import type { MarkdownRenderResult, MarkdownRenderableBlock } from "./types.js";
type RenderState = {
blocksById: Map<string, MarkdownRenderableBlock>;
warnings: string[];
warningSet: Set<string>;
unsupportedCount: number;
visited: Set<string>;
};
type RenderChunk = {
lines: string[];
isList: boolean;
};
function addWarning(state: RenderState, warning: string): void {
if (!state.warningSet.has(warning)) {
state.warningSet.add(warning);
state.warnings.push(warning);
}
}
function formatQuote(text: string): string[] {
const lines = text.split("\n");
return lines.map(line => `> ${line}`);
}
function escapePipe(value: string): string {
return value.replace(/\|/g, "\\|");
}
function renderTable(tableData: string[][]): string[] {
if (tableData.length === 0) {
return ["| |", "| --- |"];
}
const columns = tableData.reduce((max, row) => Math.max(max, row.length), 0);
if (columns === 0) {
return ["| |", "| --- |"];
}
const normalized = tableData.map(row => {
const copy = [...row];
while (copy.length < columns) {
copy.push("");
}
return copy;
});
const header = normalized[0].map(escapePipe);
const separator = new Array(columns).fill("---");
const body = normalized.slice(1).map(row => `| ${row.map(cell => escapePipe(cell ?? "")).join(" | ")} |`);
return [
`| ${header.join(" | ")} |`,
`| ${separator.join(" | ")} |`,
...body,
];
}
function childList(block: MarkdownRenderableBlock): string[] {
return Array.isArray(block.childIds) ? block.childIds : [];
}
function renderBlock(
blockId: string,
listDepth: number,
state: RenderState
): RenderChunk {
if (state.visited.has(blockId)) {
return { lines: [], isList: false };
}
state.visited.add(blockId);
const block = state.blocksById.get(blockId);
if (!block) {
state.unsupportedCount += 1;
addWarning(state, `Missing block '${blockId}' while exporting markdown.`);
return { lines: [], isList: false };
}
const text = (block.text ?? "").trim();
const flavour = block.flavour ?? "";
const type = block.type ?? "";
const children = childList(block);
switch (flavour) {
case "affine:paragraph": {
let lines: string[] = [];
if (/^h[1-6]$/.test(type)) {
const level = Number(type.slice(1));
lines = [`${"#".repeat(level)} ${text}`.trimEnd()];
} else if (type === "quote") {
lines = formatQuote(text);
} else {
lines = [text];
}
for (const childId of children) {
const child = renderBlock(childId, listDepth, state);
if (child.lines.length > 0) {
lines.push(...child.lines);
}
}
return { lines: lines.filter(line => line.length > 0), isList: false };
}
case "affine:list": {
const indent = " ".repeat(Math.max(0, listDepth));
const style = type === "numbered" ? "numbered" : type === "todo" ? "todo" : "bulleted";
const marker =
style === "numbered"
? "1."
: style === "todo"
? block.checked
? "- [x]"
: "- [ ]"
: "-";
const lines: string[] = [`${indent}${marker}${text ? ` ${text}` : ""}`];
for (const childId of children) {
const child = state.blocksById.get(childId);
const nextDepth = child?.flavour === "affine:list" ? listDepth + 1 : listDepth;
const rendered = renderBlock(childId, nextDepth, state);
if (rendered.lines.length > 0) {
lines.push(...rendered.lines);
}
}
return { lines, isList: true };
}
case "affine:code": {
const language = block.language ?? "";
const lines = [`\`\`\`${language}`, block.text ?? "", "\`\`\`"];
return { lines, isList: false };
}
case "affine:divider":
return { lines: ["---"], isList: false };
case "affine:bookmark":
case "affine:embed-youtube":
case "affine:embed-github":
case "affine:embed-figma":
case "affine:embed-loom":
case "affine:embed-iframe": {
const url = (block.url ?? "").trim();
if (!url) {
state.unsupportedCount += 1;
addWarning(state, `Bookmark/embed block '${blockId}' had no URL and was skipped.`);
return { lines: [], isList: false };
}
const label = (block.caption ?? "").trim() || text || url;
return { lines: [`[${label}](${url})`], isList: false };
}
case "affine:image": {
const source = (block.sourceId ?? "").trim();
if (!source) {
state.unsupportedCount += 1;
addWarning(state, `Image block '${blockId}' had no sourceId and was skipped.`);
return { lines: [], isList: false };
}
const alt = (block.caption ?? "").trim() || "image";
return { lines: [``], isList: false };
}
case "affine:table": {
if (!block.tableData || block.tableData.length === 0) {
state.unsupportedCount += 1;
addWarning(state, `Table block '${blockId}' had no readable cell data.`);
return { lines: ["| |", "| --- |"], isList: false };
}
return {
lines: renderTable(block.tableData),
isList: false,
};
}
case "affine:note":
case "affine:page":
case "affine:surface": {
const chunks: string[] = [];
for (const childId of children) {
const child = renderBlock(childId, listDepth, state);
if (child.lines.length > 0) {
if (chunks.length > 0 && !child.isList) {
chunks.push("");
}
chunks.push(...child.lines);
}
}
return { lines: chunks, isList: false };
}
default: {
state.unsupportedCount += 1;
addWarning(state, `Unsupported AFFiNE block flavour '${flavour || "unknown"}' was exported as a comment placeholder.`);
return {
lines: [`<!-- unsupported: flavour=${flavour || "unknown"} blockId=${blockId} -->`],
isList: false,
};
}
}
}
export function renderBlocksToMarkdown(input: {
rootBlockIds: string[];
blocksById: Map<string, MarkdownRenderableBlock>;
}): MarkdownRenderResult {
const state: RenderState = {
blocksById: input.blocksById,
warnings: [],
warningSet: new Set<string>(),
unsupportedCount: 0,
visited: new Set<string>(),
};
const chunks: RenderChunk[] = [];
for (const rootId of input.rootBlockIds) {
const rendered = renderBlock(rootId, 0, state);
if (rendered.lines.length > 0) {
chunks.push(rendered);
}
}
const lines: string[] = [];
for (let i = 0; i < chunks.length; i += 1) {
const chunk = chunks[i];
if (i > 0) {
const previous = chunks[i - 1];
const shouldInsertBlank = !(previous.isList && chunk.isList);
if (shouldInsertBlank) {
lines.push("");
}
}
lines.push(...chunk.lines);
}
return {
markdown: lines.join("\n").trimEnd(),
warnings: state.warnings,
lossy: state.unsupportedCount > 0,
stats: {
blockCount: state.visited.size,
unsupportedCount: state.unsupportedCount,
},
};
}
