"use strict";

const fs = require("fs-extra");
const path = require("path");
const { parseVariantsData } = require("../export-data/variants-data");
const { parseLigationData } = require("../export-data/ligation-data");
const { getCharMapAndSupportedLanguageList } = require("../export-data/supported-languages");

///////////////////////////////////////////////////////////////////////////////////////////////////

module.exports = async function main(argv) {
	const readmePath = path.resolve(__dirname, "../../README.md");
	let readme = await fs.readFile(readmePath, "utf-8");
	readme = (await processSsOt()).apply(readme);
	readme = (await processCherryPickingStyles()).apply(readme);
	readme = (await processSsStyles()).apply(readme);
	readme = (await processCvOt()).apply(readme);
	readme = (await processLigSetCherryPicking()).apply(readme);
	readme = (await processLigSetPreDef()).apply(readme);
	readme = (await processLigSetOt(1, g => g.tag === "calt")).apply(readme);
	readme = (await processLigSetOt(2, g => g.tag !== "calt")).apply(readme);
	readme = (await processLangList(argv)).apply(readme);
	readme = (await processPrivateBuildPlans()).apply(readme);
	await fs.writeFile(readmePath, readme);
};

async function processSsOt() {
	const variantsData = await parseVariantsData();
	const md = new MdCol("Section-OT-Stylistic-Sets");
	md.log(`<table>`);
	for (const ss of variantsData.composites) {
		if (!ss.rank) continue;
		{
			md.log(`<tr>`);
			md.log(`<td colspan="2"><code>${ss.tag}</code> — ${ss.description}</td>`);
			md.log(`</tr>`);
		}
		{
			md.log(`<tr>`);
			md.log(`<td><img src="images/stylistic-set-u-${ss.tag}-${ss.rank}.png"/></td>`);
			md.log(`<td><img src="images/stylistic-set-i-${ss.tag}-${ss.rank}.png"/></td>`);
			md.log(`</tr>`);
		}
	}
	md.log(`</table>`);
	return md;
}
async function processCvOt() {
	const variantsData = await parseVariantsData();
	const md = new MdCol("Section-OT-Character-Variants");
	const TableColumns = 12;
	md.log(`<table>`);
	for (const cv of variantsData.primes) {
		if (!cv.tag) continue;
		let effVariants = [];
		for (const cvv of cv.variants) if (cvv.rank) effVariants.push(cvv);
		const entryWidth = sampleImageCountEmOfCv(cv);
		const imgWidth = 32 * entryWidth;
		const entriesPerRow = Math.floor(TableColumns / entryWidth);
		const rowsNeeded = Math.ceil(effVariants.length / entriesPerRow);
		const itemColSpanHtml = entryWidth > 1 ? ` colspan="${entryWidth}"` : ``;

		for (let rid = 0; rid < rowsNeeded; rid++) {
			const entriesInThisRow = Math.min(
				entriesPerRow,
				effVariants.length - rid * entriesPerRow
			);
			const tailBlankColumnsCount = TableColumns - entryWidth * entriesInThisRow;

			// Image row
			md.log(`<tr>`);
			if (rid === 0) md.log(`<td rowspan="${2 * rowsNeeded}"><code>${cv.tag}</code></td>`);
			for (let cid = 0; cid < entriesPerRow; cid++) {
				const iCvv = rid * entriesPerRow + cid;
				if (iCvv >= effVariants.length) continue;
				const cvv = effVariants[iCvv];
				const imageUrl = `images/character-variant-${cv.tag}-${cvv.rank}.png`;
				md.log(`<td${itemColSpanHtml}><img src="${imageUrl}" width="${imgWidth}"/></td>`);
			}
			if (tailBlankColumnsCount > 0) md.log(`<td colspan="${tailBlankColumnsCount}"> </td>`);
			md.log(`</tr>`);

			// CV ID row
			md.log(`<tr>`);
			for (let cid = 0; cid < entriesPerRow; cid++) {
				const iCvv = rid * entriesPerRow + cid;
				if (iCvv >= effVariants.length) continue;
				const cvv = effVariants[iCvv];
				md.log(`<td${itemColSpanHtml}>${cvv.rank}</td>`);
			}
			if (tailBlankColumnsCount > 0) md.log(`<td colspan="${tailBlankColumnsCount}"> </td>`);
			md.log(`</tr>`);
		}
	}
	md.log(`</table>`);
	return md;
}

async function processSsStyles() {
	const variantsData = await parseVariantsData();
	const md = new MdCol("Section-Stylistic-Sets");
	const headerPath = path.resolve(__dirname, "fragments/description-stylistic-sets.md");
	md.log(await fs.readFile(headerPath, "utf-8"));
	for (const gr of variantsData.composites) {
		if (!gr.rank) continue;
		md.log(`  - \`${gr.tag}\`: Set character variant to “${gr.description}”.`);
	}
	return md;
}
async function processCherryPickingStyles() {
	const variantsData = await parseVariantsData();
	const md = new MdCol("Section-Cherry-Picking-Styles");

	const headerPath = path.resolve(__dirname, "fragments/description-cheery-picking-styles.md");
	md.log(await fs.readFile(headerPath, "utf-8"));

	formatCv(md, {
		introMD: `Default digit form`,
		sampleImageCountEm: 10,
		alternatives: [
			{
				imageId: "lnum",
				selectors: [`digit-form = 'lining'`],
				description: `Lining (default)`
			},
			{
				imageId: "onum",
				selectors: [`digit-form = 'old-style'`],
				description: `Old-style`
			}
		]
	});

	formatCv(md, {
		introMD: `APL form`,
		sampleImageCountEm: 7,
		alternatives: [
			{
				imageId: "APLF-off",
				selectors: [`apl-form = 'none'`],
				description: `Disable APL-specific forms`
			},
			{
				imageId: "APLF-on",
				selectors: [`apl-form = 'enable'`],
				description: `Enable APL-specific forms for operators used in APL to harmonize APL operators`
			}
		]
	});

	for (const cv of variantsData.primes) {
		if (!cv.tag) continue;
		const sampleText = cv.descSampleText
			.map(c => (c === "`" ? "`` ` ``" : `\`${c}\``))
			.join(", ");
		const explainText = cv.samplerExplain ? ` (${cv.samplerExplain})` : ``;
		const info = {
			introMD: `Styles for ${sampleText}${explainText}`,
			sampleImageCountEm: sampleImageCountEmOfCv(cv),
			alternatives: []
		};
		const defaults = figureOutDefaults(variantsData, cv);
		for (const cvv of cv.variants) {
			if (!cvv.rank) continue;

			info.alternatives.push({
				imageId: `${cv.tag}-${cvv.rank}`,
				selectors: [`${cv.key} = '${cvv.key}'`, `${cv.tag} = ${cvv.rank}`],
				description: formatDescription(cvv.description) + formatDefaults(cvv.key, defaults)
			});
		}
		formatCv(md, info);
	}
	return md;
}

function sampleImageCountEmOfCv(cv) {
	return cv.hotChars.length * (cv.slopeDependent ? 2 : 1);
}

function formatCv(md, info) {
	md.log(`  - ${info.introMD}:`);
	const imgWidth = 32 * info.sampleImageCountEm;
	let sTable = "     <table>";
	for (const alt of info.alternatives) {
		const imageUrl = `images/character-variant-${alt.imageId}.png`;
		const image = `<img src="${imageUrl}" width="${imgWidth}"/>`;
		const selectorText = alt.selectors.map(x => `<code>${x}</code>`).join(", ");
		sTable +=
			`<tr><td rowspan="2" width="${2 * 14 + imgWidth}">${image}</td>` +
			`<td>${selectorText}</td></tr>`;
		sTable += `<tr><td>${alt.description}</td></tr>`;
	}
	sTable += "</table>";
	md.log(sTable);
}

function formatDescription(s) {
	return s
		.replace(/`` (\S+?) ``/g, ($0, $1) => `<code>${escapeHtml($1)}</code>`)
		.replace(/`([^`]+?)`/g, ($0, $1) => `<code>${escapeHtml($1)}</code>`);
}

function escapeHtml(s) {
	return s.replace(/&/g, "&amp;").replace(/</g, "&lt;").replace(/>/g, "&gt;");
}

async function processPrivateBuildPlans() {
	const md = new MdCol("Section-Private-Build-Plan-Sample");
	const tomlPath = path.resolve(__dirname, "../../private-build-plans.sample.toml");
	const toml = await fs.readFile(tomlPath, "utf-8");
	md.log("```toml\n" + toml + "```");
	return md;
}

function formatDefaults(selector, defaults) {
	let dcs = [],
		mask = 0;
	for (const dc of defaults) {
		if (dc.result !== selector) continue;
		dcs.push(dc);
		mask |= dc.mask;
	}
	if (!dcs.length) return "";
	if (mask === 0xf) return ` (default)`;
	if (mask === 0x5) return ` (default for Upright)`;
	if (mask === 0xa) return ` (default for Italic)`;
	if (mask === 0x3) return ` (default for Sans)`;
	if (mask === 0xc) return ` (default for Slab)`;
	return ` (default for ${dcs.map(x => x.desc).join(", ")})`;
}

function figureOutDefaults(variantsData, gr) {
	const defaultConfigs = [
		{
			desc: "Sans Upright",
			mask: 1,
			result: null,
			composition: { ...variantsData.defaults.sansUpright }
		},
		{
			desc: "Sans Italic",
			mask: 2,
			result: null,
			composition: { ...variantsData.defaults.sansItalic }
		},
		{
			desc: "Slab Upright",
			mask: 4,
			result: null,
			composition: { ...variantsData.defaults.slabUpright }
		},
		{
			desc: "Slab Italic",
			mask: 8,
			result: null,
			composition: { ...variantsData.defaults.slabItalic }
		}
	];

	for (const variant of gr.variants) {
		for (const dc of defaultConfigs) {
			if (variant.key === dc.composition[gr.key]) dc.result = variant.key;
		}
	}
	return defaultConfigs;
}

async function processLigSetCherryPicking() {
	const ligData = await parseLigationData();
	const md = new MdCol("Section-Cherry-Picking-Ligation-Sets");
	const headerPath = path.resolve(
		__dirname,
		"fragments/description-cherry-picking-ligation-sets.md"
	);
	md.log(await fs.readFile(headerPath, "utf-8"));

	for (const gr in ligData.cherry) {
		md.log(`  - \`${gr}\`: ${ligData.cherry[gr].desc}.`);
	}
	return md;
}

async function processLigSetPreDef() {
	const ligData = await parseLigationData();
	const md = new MdCol("Section-Predefined-Ligation-Sets");
	const headerPath = path.resolve(__dirname, "fragments/description-predefined-ligation-sets.md");
	md.log(await fs.readFile(headerPath, "utf-8"));
	for (const gr in ligData.rawSets) {
		const readmeDesc =
			ligData.rawSets[gr].readmeDesc ||
			`Default ligation set would be assigned to ${ligData.rawSets[gr].desc}`;
		md.log(`  - \`${gr}\`: ${readmeDesc}.`);
	}
	return md;
}

async function processLigSetOt(index, fn) {
	const ligData = await parseLigationData();
	const md = new MdCol(`Section-OT-Ligation-Tags-${index}`);
	md.log(`<table>`);
	for (const ls of ligData.sets) {
		if (!fn(ls)) continue;
		{
			md.log(`<tr>`);
			if (ls.tagName)
				md.log(`<td>${ls.tagName.map(x => `<code>${x}</code>`).join("; ")}</td>`);
			else md.log(`<td><code>${ls.tag} off</td>`);
			md.log(`<td>${ls.desc}</td>`);
			md.log(`</tr>`);
		}
		{
			md.log(`<tr>`);
			md.log(`<td colspan="2"><img src="images/ligset-${ls.tag}-${ls.rank}.png"/></td>`);
			md.log(`</tr>`);
		}
	}
	md.log(`</table>`);
	return md;
}

async function processLangList(argv) {
	const cl = await getCharMapAndSupportedLanguageList(
		argv.charMapPath,
		argv.charMapItalicPath,
		argv.charMapObliquePath
	);
	const md = new MdCol("Section-Language-List");
	md.log(`${cl.languages.length} Supported Languages: \n`);
	md.log(cl.languages.join(", "));
	return md;
}

/////////////////////////////////////////////////////////////////////////////////////////////////////

class MdCol {
	constructor(sectionName) {
		this.data = "";
		this.sectionName = sectionName;
		this.matchRegex = new RegExp(
			`^([ \\t]*)<!-- BEGIN ${sectionName} -->\\n[\\s\\S]*?<!-- END ${sectionName} -->\\n`,
			`m`
		);
	}
	log(...s) {
		this.data += s.join("") + "\n";
	}
	apply(s) {
		return s.replace(this.matchRegex, (m, $1) => {
			return (
				`<!-- BEGIN ${this.sectionName} -->\n` +
				`<!-- THIS SECTION IS AUTOMATICALLY GENERATED. DO NOT EDIT. -->\n\n` +
				this.data +
				`\n<!-- END ${this.sectionName} -->\n`
			).replace(/^/gm, $1);
		});
	}
}