fleischwolf-core 0.1.0

//! The unified document representation.

use crate::markdown::{to_markdown, to_markdown_images};
use crate::ImageMode;

/// The unified, format-agnostic document produced by every backend.
///
/// This is the heart of docling: backends parse their source format into a
/// `DoclingDocument`, and serializers turn it back into Markdown, HTML, JSON,
/// etc. Phase 0 uses a flat sequence of [`Node`]s; the production schema will
/// match docling-core's body-tree-with-references layout.
#[derive(Debug, Clone, PartialEq)]
pub struct DoclingDocument {
    /// Logical document name (usually the input file stem).
    pub name: String,
    /// Top-level content, in reading order.
    pub nodes: Vec<Node>,
    /// Default Markdown export mode for [`Self::export_to_markdown`]. `false`
    /// (the default) reproduces docling's legacy output byte-for-byte; `true`
    /// emits cleaner, more conformant Markdown. Set by `DocumentConverter`.
    pub strict_markdown: bool,
}

/// A single piece of document content.
#[derive(Debug, Clone, PartialEq)]
pub enum Node {
    /// A heading. `level` is 1-6.
    Heading { level: u8, text: String },
    /// A run of body text.
    Paragraph { text: String },
    /// A single list item at the given nesting `level` (0 = top). For ordered
    /// items, `number` is the display number (honoring the list's `start`); it
    /// is unused for unordered items. `first_in_list` marks the first item of a
    /// list so the serializer can blank-line-separate adjacent sibling lists.
    ListItem {
        ordered: bool,
        number: u64,
        first_in_list: bool,
        text: String,
        level: u8,
    },
    /// A fenced code block.
    Code {
        language: Option<String>,
        text: String,
    },
    /// A table. The first row is treated as the header.
    Table(Table),
    /// A picture/figure, with an optional caption and (when a backend extracts
    /// it) the embedded image itself.
    Picture {
        caption: Option<String>,
        image: Option<PictureImage>,
    },
    /// A logical grouping of child nodes (e.g. a list, a section).
    Group { label: String, children: Vec<Node> },
}

/// An extracted picture's raw encoded bytes plus its mimetype and pixel size —
/// the fleischwolf analogue of docling-core's `ImageRef`.
#[derive(Debug, Clone, PartialEq)]
pub struct PictureImage {
    /// e.g. `image/png`, `image/jpeg`.
    pub mimetype: String,
    pub width: u32,
    pub height: u32,
    /// The image file bytes, exactly as embedded (PNG/JPEG/…).
    pub data: Vec<u8>,
}

impl PictureImage {
    /// A `data:` URI for the image (`data:<mimetype>;base64,<…>`).
    pub fn data_uri(&self) -> String {
        format!(
            "data:{};base64,{}",
            self.mimetype,
            crate::base64::encode(&self.data)
        )
    }
}

/// A simple row-major table. `rows[0]` is the header row.
#[derive(Debug, Clone, PartialEq)]
pub struct Table {
    pub rows: Vec<Vec<String>>,
}

impl DoclingDocument {
    /// Create an empty document with the given name.
    pub fn new(name: impl Into<String>) -> Self {
        Self {
            name: name.into(),
            nodes: Vec::new(),
            strict_markdown: false,
        }
    }

    /// Append a node.
    pub fn push(&mut self, node: Node) {
        self.nodes.push(node);
    }

    /// Convenience: append a heading.
    pub fn add_heading(&mut self, level: u8, text: impl Into<String>) {
        self.push(Node::Heading {
            level,
            text: text.into(),
        });
    }

    /// Convenience: append a paragraph.
    pub fn add_paragraph(&mut self, text: impl Into<String>) {
        self.push(Node::Paragraph { text: text.into() });
    }

    /// Serialize the document to Markdown.
    ///
    /// The Rust equivalent of docling-core's
    /// `DoclingDocument.export_to_markdown()`. Uses [`Self::strict_markdown`] to
    /// pick between docling-legacy output (default) and the cleaner, more
    /// conformant variant.
    pub fn export_to_markdown(&self) -> String {
        to_markdown(self, self.strict_markdown)
    }

    /// Serialize to Markdown, explicitly choosing the mode regardless of
    /// [`Self::strict_markdown`]. `strict = true` produces cleaner, more
    /// conformant Markdown (code-fence languages preserved, no inline-run
    /// spacing artifacts); `strict = false` reproduces docling's legacy output.
    pub fn export_to_markdown_with(&self, strict: bool) -> String {
        to_markdown(self, strict)
    }

    /// Serialize to docling-core's native JSON wire format (`DoclingDocument`
    /// schema), pretty-printed — the Rust equivalent of
    /// `DoclingDocument.export_to_dict()` / `save_as_json()`. The output loads
    /// back into Python docling-core and round-trips to the same Markdown.
    pub fn export_to_json(&self) -> String {
        serde_json::to_string_pretty(&crate::json::to_json(self))
            .expect("DoclingDocument JSON is always serializable")
    }

    /// Serialize to Markdown with an explicit picture [`ImageMode`] (mirrors
    /// docling's `image_mode`). Returns the Markdown and, for
    /// [`ImageMode::Referenced`], the `(relative-path, bytes)` of each image the
    /// caller should write next to the Markdown file. `artifacts_dir` is the
    /// directory name used in referenced links.
    pub fn export_to_markdown_with_images(
        &self,
        image_mode: ImageMode,
        artifacts_dir: &str,
    ) -> (String, Vec<(String, Vec<u8>)>) {
        to_markdown_images(self, self.strict_markdown, image_mode, artifacts_dir)
    }
}