use comrak::nodes::{AstNode, ListType, NodeValue, TableAlignment};
use comrak::{parse_document, Arena, Options};
use serde::Serialize;
use serde_json::{json, Map, Value};
use std::collections::BTreeSet;
use std::hash::{Hash, Hasher};
use std::path::{Path, PathBuf};

#[derive(Debug, Clone)]
pub struct ParsedLocalMarkdownPage {
    pub title: String,
    pub body: String,
}

#[derive(Debug, Clone)]
struct MarkdownAstDocument {
    blocks: Vec<MarkdownBlock>,
}

#[derive(Debug, Clone)]
enum MarkdownBlock {
    Paragraph(Vec<MarkdownInline>),
    Heading {
        level: u8,
        content: Vec<MarkdownInline>,
    },
    Quote(Vec<MarkdownInline>),
    CodeBlock {
        language: String,
        text: String,
    },
    Divider,
    BulletListItem(Vec<MarkdownInline>),
    NumberedListItem(Vec<MarkdownInline>),
    Todo {
        checked: bool,
        content: Vec<MarkdownInline>,
    },
    Table {
        alignments: Vec<TableAlignment>,
        rows: Vec<MarkdownTableRow>,
    },
    Image {
        alt: String,
        source_path: String,
    },
    Mindmap {
        name: String,
        source_path: String,
    },
    Media {
        name: String,
        source_path: String,
    },
}

#[derive(Debug, Clone)]
struct MarkdownTableRow {
    is_header: bool,
    cells: Vec<MarkdownTableCell>,
}

#[derive(Debug, Clone)]
struct MarkdownTableCell {
    content: Vec<MarkdownInline>,
}

#[derive(Debug, Clone, PartialEq, Eq)]
struct MarkdownInline {
    text: String,
    styles: MarkdownInlineStyles,
}

#[derive(Debug, Clone, Default, PartialEq, Eq)]
struct MarkdownInlineStyles {
    bold: bool,
    italic: bool,
    strike: bool,
    underline: bool,
    code: bool,
    link: Option<String>,
}

#[derive(Debug, Clone, PartialEq, Eq, Hash, Serialize)]
#[serde(rename_all = "camelCase")]
pub struct AttachmentSourceRange {
    pub start: usize,
    pub end: usize,
}

#[derive(Debug, Clone, PartialEq, Eq, Serialize)]
#[serde(rename_all = "camelCase")]
pub struct AttachmentRef {
    pub ref_id: String,
    pub owner_document_path: String,
    pub owner_root_uri: String,
    pub raw_href: String,
    pub normalized_href: String,
    pub label: String,
    pub kind: String,
    pub resolved_uri: Option<String>,
    pub resolved_absolute_path: Option<String>,
    pub relative_path: Option<String>,
    pub ext: Option<String>,
    pub content_type: Option<String>,
    pub exists: Option<bool>,
    pub authorized: Option<bool>,
    pub open_kind: String,
    pub source_range: Option<AttachmentSourceRange>,
}

pub fn parse_markdown_page(markdown: &str, file_name: &str) -> ParsedLocalMarkdownPage {
    let (_frontmatter, body) = split_frontmatter(markdown);
    let body_owned = body.to_string();
    // 本地 Markdown 的树标题和页头标题统一来自文件名；
    // frontmatter title 与正文 H1 都保留为正文/元数据内容，不作为资源标题真相。
    let title = file_stem_title(file_name);
    ParsedLocalMarkdownPage {
        title,
        body: body_owned,
    }
}

pub fn markdown_to_blocks(markdown: &str) -> Value {
    markdown_to_blocks_with_attachment_paths(markdown, &BTreeSet::new())
}

pub fn markdown_to_blocks_with_attachment_paths(
    markdown: &str,
    attachment_paths: &BTreeSet<String>,
) -> Value {
    markdown_ast_document_to_blocks(&parse_markdown_ast_document(markdown, attachment_paths))
}

pub fn parse_markdown_attachment_refs(
    markdown: &str,
    owner_document_path: &str,
    owner_root_uri: &str,
) -> Vec<AttachmentRef> {
    let arena = Arena::new();
    let options = markdown_options();
    let root = parse_document(&arena, markdown, &options);
    let mut refs = Vec::new();
    let mut cursor = 0usize;
    collect_attachment_refs_from_ast(
        root,
        markdown,
        owner_document_path,
        owner_root_uri,
        &mut cursor,
        &mut refs,
    );
    collect_html_embed_attachment_refs(markdown, owner_document_path, owner_root_uri, &mut refs);
    refs
}

fn markdown_options() -> Options<'static> {
    let mut options = Options::default();
    options.extension.table = true;
    options.extension.tasklist = true;
    options.extension.strikethrough = true;
    options.extension.autolink = true;
    options.extension.front_matter_delimiter = Some("---".to_string());
    options.parse.tasklist_in_table = true;
    options
}

pub fn parse_markdown_attachment_link(trimmed: &str) -> Option<(String, String)> {
    parse_markdown_attachment_link_with_paths(trimmed, &BTreeSet::new())
}

fn parse_markdown_attachment_link_with_paths(
    trimmed: &str,
    attachment_paths: &BTreeSet<String>,
) -> Option<(String, String)> {
    let value = trimmed
        .strip_prefix('!')
        .unwrap_or(trimmed)
        .strip_prefix('[')?;
    let (label, rest) = value.split_once("](")?;
    let raw_target = rest.strip_suffix(')')?.trim();
    let target = raw_target
        .strip_prefix('<')
        .and_then(|value| value.strip_suffix('>'))
        .unwrap_or(raw_target)
        .trim();
    if target.is_empty()
        || target.starts_with("http://")
        || target.starts_with("https://")
        || target.starts_with('#')
        || target.starts_with("mailto:")
    {
        return None;
    }
    let target_path = std::path::Path::new(target);
    let extension = target_path.extension().and_then(|value| value.to_str())?;
    if (extension.eq_ignore_ascii_case("md") || extension.eq_ignore_ascii_case("markdown"))
        && !attachment_paths.contains(target)
    {
        return None;
    }
    let fallback_name = target_path
        .file_name()
        .and_then(|value| value.to_str())
        .unwrap_or(target)
        .trim();
    let name = if label.trim().is_empty() {
        fallback_name
    } else {
        label.trim()
    };
    Some((name.to_string(), target.to_string()))
}

fn collect_attachment_refs_from_ast<'a>(
    node: &'a AstNode<'a>,
    markdown: &str,
    owner_document_path: &str,
    owner_root_uri: &str,
    cursor: &mut usize,
    refs: &mut Vec<AttachmentRef>,
) {
    match &node.data.borrow().value {
        NodeValue::Link(link) => {
            let raw_href = link.url.trim();
            if should_collect_attachment_href(raw_href) {
                let label = collect_plain_text(node);
                let source_range = find_href_source_range(markdown, raw_href, cursor);
                refs.push(build_attachment_ref(
                    owner_document_path,
                    owner_root_uri,
                    raw_href,
                    label.trim(),
                    source_range,
                ));
            }
        }
        NodeValue::Image(link) => {
            let raw_href = link.url.trim();
            if should_collect_attachment_href(raw_href) {
                let label = collect_plain_text(node);
                let source_range = find_href_source_range(markdown, raw_href, cursor);
                refs.push(build_attachment_ref(
                    owner_document_path,
                    owner_root_uri,
                    raw_href,
                    label.trim(),
                    source_range,
                ));
            }
        }
        _ => {}
    }
    for child in node.children() {
        collect_attachment_refs_from_ast(
            child,
            markdown,
            owner_document_path,
            owner_root_uri,
            cursor,
            refs,
        );
    }
}

fn collect_html_embed_attachment_refs(
    markdown: &str,
    owner_document_path: &str,
    owner_root_uri: &str,
    refs: &mut Vec<AttachmentRef>,
) {
    let lower = markdown.to_ascii_lowercase();
    let mut offset = 0usize;
    while let Some(relative_start) = lower[offset..].find("<embed") {
        let start = offset + relative_start;
        let Some(relative_end) = lower[start..].find('>') else {
            break;
        };
        let end = start + relative_end + 1;
        let fragment = &markdown[start..end];
        if let Some((raw_href, value_start, value_end)) =
            extract_html_attr(fragment, "src").or_else(|| extract_html_attr(fragment, "href"))
        {
            let source_range = Some(AttachmentSourceRange {
                start: start + value_start,
                end: start + value_end,
            });
            refs.push(build_attachment_ref(
                owner_document_path,
                owner_root_uri,
                raw_href,
                raw_href,
                source_range,
            ));
        }
        offset = end;
    }
}

fn extract_html_attr<'a>(fragment: &'a str, name: &str) -> Option<(&'a str, usize, usize)> {
    let lower = fragment.to_ascii_lowercase();
    let needle = format!("{name}=");
    let attr_start = lower.find(&needle)? + needle.len();
    let bytes = fragment.as_bytes();
    let quote = *bytes.get(attr_start)?;
    if quote != b'"' && quote != b'\'' {
        return None;
    }
    let value_start = attr_start + 1;
    let value_end = fragment[value_start..]
        .find(quote as char)
        .map(|index| value_start + index)?;
    Some((&fragment[value_start..value_end], value_start, value_end))
}

fn should_collect_attachment_href(raw_href: &str) -> bool {
    let trimmed = raw_href.trim();
    !trimmed.is_empty() && !trimmed.starts_with('#') && !trimmed.starts_with("mailto:")
}

fn build_attachment_ref(
    owner_document_path: &str,
    owner_root_uri: &str,
    raw_href: &str,
    label: &str,
    source_range: Option<AttachmentSourceRange>,
) -> AttachmentRef {
    let raw_href = raw_href.trim();
    let normalized_href = normalize_attachment_href(raw_href);
    let owner_document = Path::new(owner_document_path);
    let owner_dir = owner_document.parent();
    let (kind, resolved_absolute_path, relative_path) =
        resolve_attachment_path(&normalized_href, owner_dir, owner_root_uri);
    let resolved_uri = resolved_absolute_path
        .as_ref()
        .map(|path| file_uri_for_attachment_path(Path::new(path)))
        .or_else(|| {
            if is_remote_href(&normalized_href) {
                Some(normalized_href.clone())
            } else {
                None
            }
        });
    let ext = attachment_extension(&normalized_href, resolved_absolute_path.as_deref());
    let content_type = ext
        .as_deref()
        .and_then(attachment_content_type)
        .map(str::to_string);
    let exists = resolved_absolute_path
        .as_ref()
        .map(|path| Path::new(path).exists());
    let open_kind = attachment_open_kind(ext.as_deref()).to_string();
    let label = if label.trim().is_empty() {
        resolved_absolute_path
            .as_ref()
            .and_then(|path| Path::new(path).file_name())
            .and_then(|name| name.to_str())
            .or_else(|| {
                Path::new(&normalized_href)
                    .file_name()
                    .and_then(|name| name.to_str())
            })
            .unwrap_or(raw_href)
            .to_string()
    } else {
        label.trim().to_string()
    };
    AttachmentRef {
        ref_id: attachment_ref_id(owner_document_path, raw_href, &source_range),
        owner_document_path: owner_document_path.to_string(),
        owner_root_uri: owner_root_uri.to_string(),
        raw_href: raw_href.to_string(),
        normalized_href,
        label,
        kind,
        resolved_uri,
        resolved_absolute_path,
        relative_path,
        ext,
        content_type,
        exists,
        authorized: None,
        open_kind,
        source_range,
    }
}

fn resolve_attachment_path(
    href: &str,
    owner_dir: Option<&Path>,
    owner_root_uri: &str,
) -> (String, Option<String>, Option<String>) {
    if is_remote_href(href) {
        return ("remoteUrl".to_string(), None, None);
    }
    if let Some(path) = href.strip_prefix("file://").and_then(file_uri_path) {
        return (
            "externalFile".to_string(),
            Some(normalize_path_string(&path)),
            None,
        );
    }
    let href_path = Path::new(href);
    if href_path.is_absolute() {
        return (
            "externalFile".to_string(),
            Some(normalize_path_string(href_path)),
            None,
        );
    }
    let decoded_href = percent_decode_lossy(href);
    if decoded_href.starts_with("../") || decoded_href.contains("/../") {
        return ("unknown".to_string(), None, None);
    }
    let relative_path = decoded_href
        .strip_prefix("./")
        .unwrap_or(&decoded_href)
        .replace('\\', "/");
    let resolved = owner_dir.map(|dir| normalize_path_string(&dir.join(&decoded_href)));
    let root_path = owner_root_path(owner_root_uri);
    let relative_to_root = resolved
        .as_deref()
        .and_then(|path| {
            root_path
                .as_ref()
                .and_then(|root| relative_to_root_path(path, root))
        })
        .or(Some(relative_path));
    ("pageLocal".to_string(), resolved, relative_to_root)
}

fn normalize_attachment_href(raw_href: &str) -> String {
    let trimmed = raw_href
        .trim()
        .strip_prefix('<')
        .and_then(|value| value.strip_suffix('>'))
        .unwrap_or(raw_href.trim())
        .trim();
    if Path::new(trimmed).is_absolute() {
        file_uri_for_attachment_path(Path::new(trimmed))
    } else {
        trimmed.to_string()
    }
}

fn file_uri_path(value: &str) -> Option<PathBuf> {
    let path = if let Some(rest) = value.strip_prefix("localhost/") {
        format!("/{rest}")
    } else if value.starts_with('/') {
        value.to_string()
    } else {
        format!("/{value}")
    };
    Some(PathBuf::from(percent_decode_lossy(&path)))
}

fn owner_root_path(root_uri: &str) -> Option<PathBuf> {
    root_uri
        .strip_prefix("file://")
        .and_then(file_uri_path)
        .or_else(|| {
            let path = Path::new(root_uri);
            if path.is_absolute() {
                Some(path.to_path_buf())
            } else {
                None
            }
        })
}

fn relative_to_root_path(path: &str, root: &Path) -> Option<String> {
    Path::new(path)
        .strip_prefix(root)
        .ok()
        .map(|value| value.to_string_lossy().replace('\\', "/"))
}

fn find_href_source_range(
    markdown: &str,
    raw_href: &str,
    cursor: &mut usize,
) -> Option<AttachmentSourceRange> {
    let raw_href = raw_href.trim();
    let start = markdown
        .get(*cursor..)
        .and_then(|tail| tail.find(raw_href).map(|index| *cursor + index))
        .or_else(|| markdown.find(raw_href))?;
    let end = start + raw_href.len();
    *cursor = end;
    Some(AttachmentSourceRange { start, end })
}

fn is_remote_href(href: &str) -> bool {
    href.starts_with("http://") || href.starts_with("https://")
}

fn attachment_extension(href: &str, path: Option<&str>) -> Option<String> {
    path.or(Some(href))
        .and_then(|value| Path::new(value).extension())
        .and_then(|value| value.to_str())
        .map(|value| value.trim_start_matches('.').to_ascii_lowercase())
        .filter(|value| !value.is_empty())
}

fn attachment_content_type(ext: &str) -> Option<&'static str> {
    match ext {
        "png" => Some("image/png"),
        "jpg" | "jpeg" => Some("image/jpeg"),
        "gif" => Some("image/gif"),
        "webp" => Some("image/webp"),
        "svg" => Some("image/svg+xml"),
        "pdf" => Some("application/pdf"),
        "docx" => Some("application/vnd.openxmlformats-officedocument.wordprocessingml.document"),
        "pptx" => Some("application/vnd.openxmlformats-officedocument.presentationml.presentation"),
        "xlsx" => Some("application/vnd.openxmlformats-officedocument.spreadsheetml.sheet"),
        "mp3" => Some("audio/mpeg"),
        "wav" => Some("audio/wav"),
        "mp4" => Some("video/mp4"),
        "webm" => Some("video/webm"),
        "md" | "markdown" | "txt" | "rs" | "js" | "ts" | "tsx" | "jsx" | "json" | "toml"
        | "yaml" | "yml" => Some("text/plain"),
        _ => None,
    }
}

fn attachment_open_kind(ext: Option<&str>) -> &'static str {
    match ext.unwrap_or_default() {
        "png" | "jpg" | "jpeg" | "gif" | "webp" | "svg" => "image",
        "pdf" => "pdf",
        "doc" | "docx" | "ppt" | "pptx" | "xls" | "xlsx" => "office",
        "mp3" | "wav" | "ogg" | "m4a" => "audio",
        "mp4" | "webm" | "mov" | "mkv" => "video",
        "md" | "markdown" | "txt" | "rs" | "js" | "ts" | "tsx" | "jsx" | "json" | "toml"
        | "yaml" | "yml" => "text",
        "" => "unknown",
        _ => "download",
    }
}

fn normalize_path_string(path: &Path) -> String {
    let mut normalized = PathBuf::new();
    for component in path.components() {
        match component {
            std::path::Component::CurDir => {}
            std::path::Component::ParentDir => {
                normalized.pop();
            }
            _ => normalized.push(component.as_os_str()),
        }
    }
    normalized.to_string_lossy().replace('\\', "/")
}

fn file_uri_for_attachment_path(path: &Path) -> String {
    format!("file://{}", normalize_path_string(path))
}

fn percent_decode_lossy(value: &str) -> String {
    let bytes = value.as_bytes();
    let mut output = Vec::with_capacity(bytes.len());
    let mut index = 0usize;
    while index < bytes.len() {
        if bytes[index] == b'%' && index + 2 < bytes.len() {
            if let (Some(high), Some(low)) =
                (hex_value(bytes[index + 1]), hex_value(bytes[index + 2]))
            {
                output.push(high * 16 + low);
                index += 3;
                continue;
            }
        }
        output.push(bytes[index]);
        index += 1;
    }
    String::from_utf8_lossy(&output).into_owned()
}

fn hex_value(value: u8) -> Option<u8> {
    match value {
        b'0'..=b'9' => Some(value - b'0'),
        b'a'..=b'f' => Some(value - b'a' + 10),
        b'A'..=b'F' => Some(value - b'A' + 10),
        _ => None,
    }
}

fn attachment_ref_id(
    owner_document_path: &str,
    raw_href: &str,
    source_range: &Option<AttachmentSourceRange>,
) -> String {
    let mut hasher = std::collections::hash_map::DefaultHasher::new();
    owner_document_path.hash(&mut hasher);
    raw_href.hash(&mut hasher);
    source_range.hash(&mut hasher);
    format!("attachment:{:016x}", hasher.finish())
}

fn parse_markdown_ast_document(
    markdown: &str,
    attachment_paths: &BTreeSet<String>,
) -> MarkdownAstDocument {
    let arena = Arena::new();
    let options = markdown_options();
    let root = parse_document(&arena, markdown, &options);
    let mut blocks = Vec::new();
    for node in root.children() {
        append_ast_block(node, &mut blocks, attachment_paths);
    }
    MarkdownAstDocument { blocks }
}

fn append_ast_block<'a>(
    node: &'a AstNode<'a>,
    blocks: &mut Vec<MarkdownBlock>,
    attachment_paths: &BTreeSet<String>,
) {
    match node.data.borrow().value.clone() {
        NodeValue::Paragraph => append_ast_paragraph(node, blocks, attachment_paths),
        NodeValue::Heading(heading) => blocks.push(MarkdownBlock::Heading {
            level: heading.level,
            content: collect_inline_children(node),
        }),
        NodeValue::BlockQuote => blocks.push(MarkdownBlock::Quote(collect_inline_children(node))),
        NodeValue::ThematicBreak => blocks.push(MarkdownBlock::Divider),
        NodeValue::CodeBlock(code_block) => blocks.push(MarkdownBlock::CodeBlock {
            language: code_block.info.clone(),
            text: code_block.literal.clone(),
        }),
        NodeValue::List(list) => {
            for item in node.children() {
                append_ast_list_item(
                    item,
                    list.list_type == ListType::Ordered,
                    blocks,
                    attachment_paths,
                );
            }
        }
        NodeValue::Table(table) => blocks.push(ast_table_to_ir(node, table.alignments)),
        NodeValue::HtmlBlock(html) => blocks.push(MarkdownBlock::Paragraph(vec![MarkdownInline {
            text: html.literal.clone(),
            styles: MarkdownInlineStyles::default(),
        }])),
        NodeValue::FrontMatter(_) => {}
        _ => {
            let text = collect_plain_text(node);
            if !text.is_empty() {
                blocks.push(MarkdownBlock::Paragraph(vec![MarkdownInline {
                    text,
                    styles: MarkdownInlineStyles::default(),
                }]));
            }
        }
    }
}

fn append_ast_paragraph<'a>(
    node: &'a AstNode<'a>,
    blocks: &mut Vec<MarkdownBlock>,
    attachment_paths: &BTreeSet<String>,
) {
    if let Some((alt, source_path)) = paragraph_image(node) {
        blocks.push(MarkdownBlock::Image { alt, source_path });
        return;
    }
    if let Some((name, source_path)) = paragraph_mindmap(node) {
        blocks.push(MarkdownBlock::Mindmap { name, source_path });
        return;
    }
    if let Some((name, source_path)) = paragraph_attachment_media(node, attachment_paths) {
        blocks.push(MarkdownBlock::Media { name, source_path });
        return;
    }
    if let Some((name, source_path, remaining)) =
        paragraph_leading_attachment_media(node, attachment_paths)
    {
        blocks.push(MarkdownBlock::Media { name, source_path });
        let content = merge_adjacent_inline_nodes(remaining);
        if !content.is_empty() {
            blocks.push(MarkdownBlock::Paragraph(content));
        }
        return;
    }
    blocks.push(MarkdownBlock::Paragraph(collect_inline_children(node)));
}

fn append_ast_list_item<'a>(
    node: &'a AstNode<'a>,
    ordered: bool,
    blocks: &mut Vec<MarkdownBlock>,
    attachment_paths: &BTreeSet<String>,
) {
    let (is_task, checked) = match node.data.borrow().value.clone() {
        NodeValue::TaskItem(task_item) => (true, task_item.symbol.is_some()),
        NodeValue::Item(_) => (false, false),
        _ => return append_ast_block(node, blocks, attachment_paths),
    };
    let mut content = Vec::new();
    for child in node.children() {
        match child.data.borrow().value.clone() {
            NodeValue::Paragraph => content.extend(collect_inline_children(child)),
            _ => append_ast_block(child, blocks, attachment_paths),
        }
    }

    if is_task {
        blocks.push(MarkdownBlock::Todo { checked, content });
    } else if ordered {
        blocks.push(MarkdownBlock::NumberedListItem(content));
    } else {
        blocks.push(MarkdownBlock::BulletListItem(content));
    }
}

fn ast_table_to_ir<'a>(node: &'a AstNode<'a>, alignments: Vec<TableAlignment>) -> MarkdownBlock {
    let rows = node
        .children()
        .map(|row| {
            let is_header = matches!(row.data.borrow().value, NodeValue::TableRow(true));
            let cells = row
                .children()
                .map(|cell| MarkdownTableCell {
                    content: collect_inline_children(cell),
                })
                .collect::<Vec<_>>();
            MarkdownTableRow { is_header, cells }
        })
        .collect::<Vec<_>>();
    MarkdownBlock::Table { alignments, rows }
}

fn collect_inline_children<'a>(node: &'a AstNode<'a>) -> Vec<MarkdownInline> {
    let mut nodes = Vec::new();
    for child in node.children() {
        collect_inline_nodes(child, &MarkdownInlineStyles::default(), &mut nodes);
    }
    merge_adjacent_inline_nodes(nodes)
}

fn collect_inline_nodes<'a>(
    node: &'a AstNode<'a>,
    active_styles: &MarkdownInlineStyles,
    nodes: &mut Vec<MarkdownInline>,
) {
    match node.data.borrow().value.clone() {
        NodeValue::Text(text) => push_inline_text_node(nodes, text.as_ref(), active_styles),
        NodeValue::TaskItem(task_item) => {
            let marker = if task_item.symbol.is_some() {
                "[x] "
            } else {
                "[ ] "
            };
            push_inline_text_node(nodes, marker, active_styles);
            for child in node.children() {
                collect_inline_nodes(child, active_styles, nodes);
            }
        }
        NodeValue::Code(code) => {
            let mut styles = active_styles.clone();
            styles.code = true;
            push_inline_text_node(nodes, &code.literal, &styles);
        }
        NodeValue::Strong => {
            let mut styles = active_styles.clone();
            styles.bold = true;
            collect_inline_children_with_styles(node, &styles, nodes);
        }
        NodeValue::Emph => {
            let mut styles = active_styles.clone();
            styles.italic = true;
            collect_inline_children_with_styles(node, &styles, nodes);
        }
        NodeValue::Strikethrough => {
            let mut styles = active_styles.clone();
            styles.strike = true;
            collect_inline_children_with_styles(node, &styles, nodes);
        }
        NodeValue::Underline => {
            let mut styles = active_styles.clone();
            styles.underline = true;
            collect_inline_children_with_styles(node, &styles, nodes);
        }
        NodeValue::Link(link) => {
            let mut styles = active_styles.clone();
            styles.link = Some(link.url.clone());
            collect_inline_children_with_styles(node, &styles, nodes);
        }
        NodeValue::SoftBreak | NodeValue::LineBreak => {
            push_inline_text_node(nodes, " ", active_styles);
        }
        NodeValue::HtmlInline(text) => push_inline_text_node(nodes, text.as_ref(), active_styles),
        NodeValue::Image(link) => {
            let mut styles = active_styles.clone();
            styles.link = Some(link.url.clone());
            push_inline_text_node(nodes, link.url.as_str(), &styles);
        }
        _ => collect_inline_children_with_styles(node, active_styles, nodes),
    }
}

fn collect_inline_children_with_styles<'a>(
    node: &'a AstNode<'a>,
    active_styles: &MarkdownInlineStyles,
    nodes: &mut Vec<MarkdownInline>,
) {
    for child in node.children() {
        collect_inline_nodes(child, active_styles, nodes);
    }
}

fn push_inline_text_node(
    nodes: &mut Vec<MarkdownInline>,
    text: &str,
    styles: &MarkdownInlineStyles,
) {
    if text.is_empty() {
        return;
    }
    nodes.push(MarkdownInline {
        text: text.to_string(),
        styles: styles.clone(),
    });
}

fn merge_adjacent_inline_nodes(nodes: Vec<MarkdownInline>) -> Vec<MarkdownInline> {
    let mut merged = Vec::<MarkdownInline>::new();
    for node in nodes {
        if let Some(last) = merged.last_mut() {
            if last.styles == node.styles {
                last.text.push_str(&node.text);
                continue;
            }
        }
        merged.push(node);
    }
    merged
}

fn paragraph_attachment_media<'a>(
    node: &'a AstNode<'a>,
    attachment_paths: &BTreeSet<String>,
) -> Option<(String, String)> {
    let mut children = node.children();
    let first = children.next()?;
    if children.next().is_some() {
        return None;
    }
    link_attachment_media(first, attachment_paths)
}

fn paragraph_mindmap<'a>(node: &'a AstNode<'a>) -> Option<(String, String)> {
    let mut children = node.children();
    let first = children.next()?;
    if children.next().is_some() {
        return None;
    }
    link_mindmap(first)
}

fn paragraph_image<'a>(node: &'a AstNode<'a>) -> Option<(String, String)> {
    let mut children = node.children();
    let first = children.next()?;
    if children.next().is_some() {
        return None;
    }
    let NodeValue::Image(link) = &first.data.borrow().value else {
        return None;
    };
    let alt = collect_plain_text(first).trim().to_string();
    Some((alt, link.url.clone()))
}

fn paragraph_leading_attachment_media<'a>(
    node: &'a AstNode<'a>,
    attachment_paths: &BTreeSet<String>,
) -> Option<(String, String, Vec<MarkdownInline>)> {
    let mut children = node.children();
    let first = children.next()?;
    let (name, source_path) = link_attachment_media(first, attachment_paths)?;
    let second = children.next()?;
    if !matches!(
        second.data.borrow().value,
        NodeValue::SoftBreak | NodeValue::LineBreak
    ) {
        return None;
    }
    let mut remaining = Vec::new();
    for child in children {
        collect_inline_nodes(child, &MarkdownInlineStyles::default(), &mut remaining);
    }
    Some((name, source_path, remaining))
}

fn link_attachment_media<'a>(
    node: &'a AstNode<'a>,
    attachment_paths: &BTreeSet<String>,
) -> Option<(String, String)> {
    let NodeValue::Link(link) = &node.data.borrow().value else {
        return None;
    };
    parse_markdown_attachment_link_with_paths(
        &format!("[{}]({})", collect_plain_text(node), link.url),
        attachment_paths,
    )
}

fn link_mindmap<'a>(node: &'a AstNode<'a>) -> Option<(String, String)> {
    let NodeValue::Link(link) = &node.data.borrow().value else {
        return None;
    };
    let target = link.url.trim();
    let file_name = std::path::Path::new(target)
        .file_name()
        .and_then(|value| value.to_str())
        .unwrap_or(target)
        .trim();
    let lower = file_name.to_ascii_lowercase();
    let is_mindmap = lower.ends_with(".mindmap.json")
        || (file_name.starts_with("思维导图") && lower.ends_with(".json"));
    if !is_mindmap {
        return None;
    }
    let name = collect_plain_text(node).trim().to_string();
    Some((
        if name.is_empty() {
            "思维导图".to_string()
        } else {
            name
        },
        target.to_string(),
    ))
}

fn markdown_ast_document_to_blocks(document: &MarkdownAstDocument) -> Value {
    Value::Array(
        document
            .blocks
            .iter()
            .enumerate()
            .map(|(index, block)| markdown_block_to_json(block, index + 1))
            .collect(),
    )
}

fn markdown_block_to_json(block: &MarkdownBlock, block_number: usize) -> Value {
    match block {
        MarkdownBlock::Paragraph(content) => json_block(
            "paragraph",
            legacy_inline_nodes_to_json(content),
            block_number,
        ),
        MarkdownBlock::Heading { level, content } => json!({
            "id": format!("local-block-{block_number}"),
            "type": "heading",
            "props": { "level": level },
            "content": legacy_inline_nodes_to_json(content),
            "children": [],
        }),
        MarkdownBlock::Quote(content) => {
            json_block("quote", legacy_inline_nodes_to_json(content), block_number)
        }
        MarkdownBlock::CodeBlock { language, text } => json!({
            "id": format!("local-block-{block_number}"),
            "type": "codeBlock",
            "props": { "language": language },
            "content": [{ "type": "text", "text": text, "styles": {} }],
            "children": [],
        }),
        MarkdownBlock::Divider => json!({
            "id": format!("local-block-{block_number}"),
            "type": "divider",
            "content": [],
            "children": [],
        }),
        MarkdownBlock::BulletListItem(content) => json_block(
            "bulletListItem",
            legacy_inline_nodes_to_json(content),
            block_number,
        ),
        MarkdownBlock::NumberedListItem(content) => json_block(
            "numberedListItem",
            legacy_inline_nodes_to_json(content),
            block_number,
        ),
        MarkdownBlock::Todo { checked, content } => json!({
            "id": format!("local-block-{block_number}"),
            "type": "todo",
            "props": { "checked": checked },
            "content": legacy_inline_nodes_to_json(content),
            "children": [],
        }),
        MarkdownBlock::Table { alignments, rows } => {
            table_block_to_json(alignments, rows, block_number)
        }
        MarkdownBlock::Image { alt, source_path } => json!({
            "id": format!("local-block-{block_number}"),
            "type": "image",
            "props": {
                "src": source_path,
                "alt": alt,
                "title": alt,
            },
            "content": [],
            "children": [],
        }),
        MarkdownBlock::Mindmap { name, source_path } => json!({
            "id": format!("local-block-{block_number}"),
            "type": "mindmap",
            "props": {
                "name": name,
                "sourcePath": source_path,
                "mindmapId": source_path,
                "rootNodeId": "root",
            },
            "content": [],
            "children": [],
        }),
        MarkdownBlock::Media { name, source_path } => json!({
            "id": format!("local-block-{block_number}"),
            "type": "media",
            "props": {
                "name": name,
                "sourcePath": source_path,
            },
            "content": [],
            "children": [],
        }),
    }
}

fn table_block_to_json(
    alignments: &[TableAlignment],
    rows: &[MarkdownTableRow],
    block_number: usize,
) -> Value {
    let content_rows = rows
        .iter()
        .map(|row| {
            let cells = row
                .cells
                .iter()
                .enumerate()
                .map(|(column_index, cell)| {
                    let cell_type = if row.is_header {
                        "tableHeader"
                    } else {
                        "tableCell"
                    };
                    let text_align = match alignments
                        .get(column_index)
                        .copied()
                        .unwrap_or(TableAlignment::None)
                    {
                        TableAlignment::Left => "left",
                        TableAlignment::Center => "center",
                        TableAlignment::Right => "right",
                        TableAlignment::None => "",
                    };
                    json!({
                        "type": cell_type,
                        "attrs": {
                            "colspan": 1,
                            "rowspan": 1,
                            "colwidth": null,
                            "textAlign": text_align,
                        },
                        "content": [{
                            "type": "paragraph",
                            "content": tiptap_inline_nodes_to_json(&cell.content),
                        }]
                    })
                })
                .collect::<Vec<_>>();
            json!({
                "type": "tableRow",
                "content": cells,
            })
        })
        .collect::<Vec<_>>();
    json!({
        "id": format!("local-block-{block_number}"),
        "type": "table",
        "props": {
            "tiptapTable": {
                "type": "table",
                "attrs": { "blockId": format!("local-block-{block_number}") },
                "content": content_rows,
            }
        },
        "content": [],
        "children": [],
    })
}

fn json_block(block_type: &str, content: Vec<Value>, block_number: usize) -> Value {
    json!({
        "id": format!("local-block-{block_number}"),
        "type": block_type,
        "content": content,
        "children": [],
    })
}

fn legacy_inline_nodes_to_json(nodes: &[MarkdownInline]) -> Vec<Value> {
    nodes
        .iter()
        .map(|node| {
            json!({
                "type": "text",
                "text": node.text,
                "styles": legacy_styles_to_json(&node.styles),
            })
        })
        .collect()
}

fn legacy_styles_to_json(styles: &MarkdownInlineStyles) -> Value {
    let mut object = Map::new();
    if styles.bold {
        object.insert("bold".to_string(), Value::Bool(true));
    }
    if styles.italic {
        object.insert("italic".to_string(), Value::Bool(true));
    }
    if styles.strike {
        object.insert("strike".to_string(), Value::Bool(true));
    }
    if styles.underline {
        object.insert("underline".to_string(), Value::Bool(true));
    }
    if styles.code {
        object.insert("code".to_string(), Value::Bool(true));
    }
    if let Some(href) = styles
        .link
        .as_deref()
        .map(str::trim)
        .filter(|href| !href.is_empty())
    {
        object.insert("link".to_string(), Value::String(href.to_string()));
    }
    Value::Object(object)
}

fn tiptap_inline_nodes_to_json(nodes: &[MarkdownInline]) -> Vec<Value> {
    nodes
        .iter()
        .filter(|node| !node.text.is_empty())
        .map(|node| {
            let mut object = Map::new();
            object.insert("type".to_string(), Value::String("text".to_string()));
            object.insert("text".to_string(), Value::String(node.text.clone()));
            let marks = tiptap_marks_from_styles(&node.styles);
            if !marks.is_empty() {
                object.insert("marks".to_string(), Value::Array(marks));
            }
            Value::Object(object)
        })
        .collect()
}

fn tiptap_marks_from_styles(styles: &MarkdownInlineStyles) -> Vec<Value> {
    let mut marks = Vec::new();
    if styles.bold {
        marks.push(json!({ "type": "bold" }));
    }
    if styles.italic {
        marks.push(json!({ "type": "italic" }));
    }
    if styles.underline {
        marks.push(json!({ "type": "underline" }));
    }
    if styles.strike {
        marks.push(json!({ "type": "strike" }));
    }
    if styles.code {
        marks.push(json!({ "type": "code" }));
    }
    if let Some(href) = styles
        .link
        .as_deref()
        .map(str::trim)
        .filter(|href| !href.is_empty())
    {
        marks.push(json!({ "type": "link", "attrs": { "href": href } }));
    }
    marks
}

fn collect_plain_text<'a>(node: &'a AstNode<'a>) -> String {
    let mut parts = Vec::new();
    for descendant in node.descendants() {
        if let NodeValue::Text(text) = &descendant.data.borrow().value {
            parts.push(text.as_ref().to_string());
        }
    }
    parts.join("")
}

pub(crate) fn split_frontmatter(markdown: &str) -> (Option<String>, &str) {
    let normalized = markdown.strip_prefix('\u{feff}').unwrap_or(markdown);
    if !normalized.starts_with("---\n") {
        return (None, normalized);
    }
    let rest = &normalized[4..];
    if let Some(end) = rest.find("\n---\n") {
        let frontmatter = rest[..end].to_string();
        let body = &rest[end + 5..];
        return (Some(frontmatter), body);
    }
    (None, normalized)
}

pub(crate) fn file_stem_title(file_name: &str) -> String {
    std::path::Path::new(file_name)
        .file_stem()
        .and_then(|stem| stem.to_str())
        .map(str::trim)
        .filter(|value| !value.is_empty())
        .unwrap_or(file_name)
        .to_string()
}

#[cfg(test)]
mod tests {
    use super::{markdown_to_blocks, parse_markdown_attachment_refs, parse_markdown_page};

    #[test]
    fn markdown_image_parses_as_image_block() {
        let blocks = markdown_to_blocks("![示例图片](assets/photo.jpg)\n");
        let first = blocks
            .as_array()
            .and_then(|items| items.first())
            .expect("first block");

        assert_eq!(first["type"].as_str(), Some("image"));
        assert_eq!(first["props"]["src"].as_str(), Some("assets/photo.jpg"));
        assert_eq!(first["props"]["alt"].as_str(), Some("示例图片"));
    }

    #[test]
    fn markdown_attachment_refs_parse_standard_href_variants() {
        let root = std::env::temp_dir().join(format!(
            "mnote-attachment-ref-parser-{}",
            std::process::id()
        ));
        let owner_dir = root.join("docs");
        std::fs::create_dir_all(&owner_dir).expect("create owner dir");
        std::fs::write(owner_dir.join("同目录 文件.pdf"), b"pdf").expect("write relative file");
        std::fs::write(owner_dir.join("figure.png"), b"png").expect("write image file");
        let owner = owner_dir.join("page.md");
        let external = root.join("external.docx");
        std::fs::write(&external, b"docx").expect("write external file");
        let markdown = format!(
            "[同目录 PDF](./%E5%90%8C%E7%9B%AE%E5%BD%95%20%E6%96%87%E4%BB%B6.pdf)\n\
![图片](./figure.png)\n\
[外部](file://{})\n\
[网页资料](https://example.com/paper.pdf)\n\
[裸绝对]({})\n\
<embed src=\"./missing.pptx\">\n",
            external.display(),
            external.display()
        );

        let refs = parse_markdown_attachment_refs(
            &markdown,
            &owner.display().to_string(),
            &format!("file://{}", root.display()),
        );

        assert_eq!(refs.len(), 6);
        assert_eq!(
            refs[0].raw_href,
            "./%E5%90%8C%E7%9B%AE%E5%BD%95%20%E6%96%87%E4%BB%B6.pdf"
        );
        assert_eq!(refs[0].kind, "pageLocal");
        assert_eq!(refs[0].open_kind, "pdf");
        assert_eq!(refs[0].exists, Some(true));
        assert_eq!(
            refs[0].relative_path,
            Some("docs/同目录 文件.pdf".to_string())
        );
        assert_eq!(refs[1].open_kind, "image");
        assert_eq!(refs[2].kind, "externalFile");
        assert_eq!(refs[2].open_kind, "office");
        assert_eq!(refs[3].kind, "remoteUrl");
        assert_eq!(
            refs[3].resolved_uri,
            Some("https://example.com/paper.pdf".to_string())
        );
        assert_eq!(
            refs[4].normalized_href,
            format!("file://{}", external.display())
        );
        assert_eq!(refs[5].raw_href, "./missing.pptx");
        assert_eq!(refs[5].open_kind, "office");
        assert_eq!(refs[5].exists, Some(false));
        assert!(refs.iter().all(|item| item.source_range.is_some()));

        let _ = std::fs::remove_dir_all(&root);
    }

    #[test]
    fn markdown_attachment_refs_do_not_resolve_parent_directory_relative_paths() {
        let root = std::env::temp_dir().join(format!(
            "mnote-attachment-ref-parent-relative-{}",
            std::process::id()
        ));
        let owner_dir = root.join("docs");
        std::fs::create_dir_all(&owner_dir).expect("create owner dir");
        let owner = owner_dir.join("page.md");

        let refs = parse_markdown_attachment_refs(
            "[上级目录](../assets/a.pdf)\n",
            &owner.display().to_string(),
            &format!("file://{}", root.display()),
        );

        assert_eq!(refs.len(), 1);
        assert_eq!(refs[0].raw_href, "../assets/a.pdf");
        assert_eq!(refs[0].kind, "unknown");
        assert_eq!(refs[0].resolved_absolute_path, None);
        assert_eq!(refs[0].relative_path, None);
        assert_eq!(refs[0].exists, None);

        let _ = std::fs::remove_dir_all(&root);
    }

    /// 固定空引用块行为：`>` 在 GFM AST 中产生 BlockQuote 节点，
    /// collect_inline_children 返回空 vec → 输出 type=quote content=[]。
    #[test]
    fn markdown_empty_blockquote_parse() {
        let blocks = markdown_to_blocks("> \n\n>");
        let array = blocks.as_array().expect("blocks");
        assert!(!array.is_empty(), "应至少产生一个引用块");
        for block in array.iter() {
            if block["type"].as_str() == Some("quote") {
                let content = block["content"].as_array().expect("quote content");
                assert!(
                    content.is_empty(),
                    "空引用块 content 应为空，实际 {:?}",
                    content
                );
            }
        }
    }

    /// 固定空表格单元格行为：comrak 解析空单元格为空的 tiptap paragraph，
    /// content 字段为 []。
    #[test]
    fn markdown_table_empty_cells_parse() {
        let blocks = markdown_to_blocks("| 左 |  |\n| --- | --- |\n|  | 右 |\n");
        let array = blocks.as_array().expect("blocks");
        let table = array
            .iter()
            .find(|b| b["type"].as_str() == Some("table"))
            .expect("should have table block");
        let tiptap_table = table["props"]["tiptapTable"]
            .as_object()
            .expect("tiptapTable object");
        let content_rows = tiptap_table["content"]
            .as_array()
            .expect("table content rows");
        // 表头行：两个单元格
        let header_row = &content_rows[0]["content"]
            .as_array()
            .expect("header row cells");
        assert_eq!(header_row.len(), 2);
        // 表头第一个单元格（非空）
        let h1_cell = &header_row[0]["content"]
            .as_array()
            .expect("header cell paragraphs");
        assert!(!h1_cell.is_empty(), "表头第一个单元格不应为空");
        // 表头第二个单元格（空）：单元格的 content 为 [{type:"paragraph", content:[]}]
        // 段落层的 content 应为空数组
        let h2_par_content = &header_row[1]["content"][0]["content"];
        let h2_inline = h2_par_content.as_array().expect("header cell para content");
        assert!(
            h2_inline.is_empty(),
            "空表头单元格的 paragraph content 应为空，实际值: {}",
            serde_json::to_string_pretty(h2_par_content).unwrap()
        );

        // 数据行
        let data_row = &content_rows[1]["content"]
            .as_array()
            .expect("data row cells");
        assert_eq!(data_row.len(), 2);
        // 数据行第一个单元格（空）：段落层的 content 应为空数组
        let d1_par_content = &data_row[0]["content"][0]["content"];
        let d1_inline = d1_par_content.as_array().expect("data cell para content");
        assert!(
            d1_inline.is_empty(),
            "空数据单元格的 paragraph content 应为空，实际值: {}",
            serde_json::to_string_pretty(d1_par_content).unwrap()
        );
        // 数据行第二个单元格（非空）：段落层的 content 不应为空
        let d2_par_content = &data_row[1]["content"][0]["content"];
        let d2_inline = d2_par_content.as_array().expect("data cell para content");
        assert!(!d2_inline.is_empty(), "非空数据单元格不应为空");
    }

    // 本地 Markdown 标题统一来自文件名，frontmatter title 和 H1 都只保留为正文/元数据。

    #[test]
    fn parse_markdown_title_uses_filename_over_frontmatter_and_h1() {
        let parsed = parse_markdown_page(
            "---\ntitle: Frontmatter Title\n---\n# H1 Heading\nbody\n",
            "File Name.md",
        );
        assert_eq!(parsed.title, "File Name");
    }

    #[test]
    fn parse_markdown_title_uses_filename_when_h1_exists() {
        let parsed = parse_markdown_page("# H1 Title\nbody\n## Not H1\n", "File Name.md");
        assert_eq!(parsed.title, "File Name");
    }

    #[test]
    fn parse_markdown_title_uses_filename_when_body_has_no_h1() {
        let parsed = parse_markdown_page("plain text\nmore text\n", "My File.md");
        assert_eq!(parsed.title, "My File");
    }

    #[test]
    fn parse_markdown_title_ignores_frontmatter_without_title() {
        let parsed = parse_markdown_page("---\ntags: foo\n---\nplain text\n", "NoH1.md");
        assert_eq!(parsed.title, "NoH1");
    }

    #[test]
    fn parse_markdown_title_ignores_hash_inside_code_block() {
        let parsed = parse_markdown_page("```md\n# Not A Title\n```\nplain text\n", "Fallback.md");
        assert_eq!(parsed.title, "Fallback");
    }
}