/**
 * Morfo DOM-validation check.
 *
 * For each morfo at `src/uix/morfo/components/*.ts`:
 *   1. Navigate to the matching routed demo at `/uix/components/{kebab}`.
 *   2. For every `public` part declared in the morfo, query the DOM for
 *      `[data-{component}-{part}]` (or `[data-{component}]` for root).
 *   3. For each matching element, verify:
 *        - Every data-attr the morfo declares with `severity: 'required'`
 *          is present.
 *        - Every data-attr with `values: [...]` has a value in that set.
 *        - No `data-{component}-*` attr is present that isn't declared in
 *          the morfo (strict mode — excludes `data-_*` privates).
 *
 * Runs after `npm run smoke` passes. Requires `npm run dev` running.
 * Morfos without a current routed demo are reported as SKIP.
 *
 * Exit codes:
 *   0 — all routed morfos validate against their rendered DOM.
 *   1 — at least one morfo-vs-DOM discrepancy.
 *   2 — no dev server / couldn't load morfos / no routed morfos.
 */

import { chromium, type Page } from 'playwright';
import { existsSync, readdirSync } from 'node:fs';
import { fileURLToPath, pathToFileURL } from 'node:url';
import { dirname, join } from 'node:path';
import type { Morfo, MorfoPart, MorfoData } from '../src/uix/morfo/types';
import { validateMorfo } from '../src/uix/morfo/schema';

const __dirname = dirname(fileURLToPath(import.meta.url));
const MORFOS_DIR = join(__dirname, '..', 'src', 'uix', 'morfo', 'components');
const ROUTES_DIR = join(__dirname, '..', 'web', 'routes');
const DEFAULT_ROUTE_PREFIX = '/uix/components';
const routePrefix = normaliseRoutePrefix(process.env.MORFO_ROUTE_PREFIX ?? DEFAULT_ROUTE_PREFIX);

function normaliseRoutePrefix(value: string): string {
	const trimmed = value.trim().replace(/\/+$/, '');
	if (!trimmed || trimmed === '/') return '';
	return trimmed.startsWith('/') ? trimmed : `/${trimmed}`;
}

function routeToPageFile(route: string): string {
	const segments = route
		.split('/')
		.filter(Boolean)
		.filter((segment) => !(segment.startsWith('(') && segment.endsWith(')')));

	return join(ROUTES_DIR, ...segments, '+page.svelte');
}

function routeForMorfo(morfo: Morfo): string | null {
	const route = `${routePrefix}/${morfo.kebab}`.replace(/\/+/g, '/');
	return existsSync(routeToPageFile(route)) ? route : null;
}

async function probePort(start: number, end: number): Promise<string | null> {
	for (let port = start; port <= end; port++) {
		try {
			const res = await fetch(`http://localhost:${port}/`, {
				signal: AbortSignal.timeout(500)
			});
			if (res.ok || res.status === 404 || res.status === 500) {
				return `http://localhost:${port}`;
			}
		} catch {
			// try next
		}
	}
	return null;
}

async function loadMorfos(): Promise<Morfo[]> {
	const files = readdirSync(MORFOS_DIR).filter(
		(f) => f.endsWith('.ts') && !f.endsWith('.test.ts')
	);
	const out: Morfo[] = [];
	for (const f of files) {
		// Use file:// URL on Windows — absolute paths starting with "g:" are
		// rejected by Node's ESM loader.
		const url = pathToFileURL(join(MORFOS_DIR, f)).href;
		const mod = (await import(url)) as Record<string, unknown>;
		for (const v of Object.values(mod)) {
			if (typeof v === 'object' && v !== null && 'kebab' in v && 'parts' in v) {
				out.push(validateMorfo(v));
			}
		}
	}
	return out;
}

type Issue = { kind: 'missing' | 'bad-value' | 'undeclared'; message: string };

/** Flatten morfo parts into a flat array for validation lookup. */
function flatParts(parts: readonly MorfoPart[]): MorfoPart[] {
	const out: MorfoPart[] = [];
	for (const p of parts) {
		out.push(p);
		if (p.parts && p.parts.length > 0) out.push(...flatParts(p.parts));
	}
	return out;
}

function dataAttrFor(kebab: string, part: MorfoPart): string {
	return part.kebab === 'provider' ? `data-${kebab}` : `data-${kebab}-${part.kebab}`;
}

async function validateMorfoAgainstDom(page: Page, morfo: Morfo): Promise<Issue[]> {
	const issues: Issue[] = [];
	const parts = flatParts(morfo.parts).filter((p) => p.kind === 'public');

	// Collect every part-identifying attr across the morfo so a part can
	// legitimately carry a sibling's identifying attr (e.g. tag-group Link
	// is a variant of Item, the <a> element carries both data-tag-group-link
	// and data-tag-group-item).
	const allPartAttrs = new Set(parts.map((p) => dataAttrFor(morfo.kebab, p)));

	for (const part of parts) {
		const partAttr = dataAttrFor(morfo.kebab, part);

		// All elements on the page that carry this part's identifying attr.
		const elementsAttrs = await page.$$eval(`[${partAttr}]`, (nodes) =>
			nodes.map((el) =>
				Array.from(el.attributes)
					.filter((a) => a.name.startsWith('data-'))
					.map((a) => ({ name: a.name, value: a.value }))
			)
		);

		if (elementsAttrs.length === 0) {
			// Not on the demo page — skip validation entirely. Morfo "optional"
			// vs "required" is about composition validity (whether a consumer
			// MAY omit the part), not about demo-page presence. Dialog.Content
			// is required in a valid composition but only mounts when
			// `open=true`, which the static demo page may not exercise.
			//
			// A dedicated permutation-matrix script (future) will exercise
			// each component through its state space and validate part
			// presence per permutation. For now, demo presence is advisory.
			continue;
		}

		const declared = new Set(part.data.map((d) => d.attr));
		declared.add(partAttr); // the part-identifying attr itself
		// Sibling parts' identifying attrs are legitimate (Link-is-Item pattern).
		for (const siblingAttr of allPartAttrs) declared.add(siblingAttr);
		const declaredByAttr = new Map<string, MorfoData>(
			part.data.map((d) => [d.attr, d])
		);

		for (const elAttrs of elementsAttrs) {
			// (a) required attrs present
			for (const data of part.data) {
				if ((data.severity ?? 'required') !== 'required') continue;
				const found = elAttrs.find((a) => a.name === data.attr);
				if (!found) {
					issues.push({
						kind: 'missing',
						message: `${morfo.kebab}.${part.kebab}: required attr "${data.attr}" not emitted`
					});
				}
			}

			// (b) enum-valued attrs have valid values
			for (const { name, value } of elAttrs) {
				const decl = declaredByAttr.get(name);
				if (decl?.values && !decl.values.includes(value)) {
					issues.push({
						kind: 'bad-value',
						message: `${morfo.kebab}.${part.kebab}: "${name}" has value "${value}", morfo declares [${decl.values.join(', ')}]`
					});
				}
			}

			// (c) no undeclared public data-{component}-* attrs
			for (const { name } of elAttrs) {
				if (!name.startsWith(`data-${morfo.kebab}`) && !name.startsWith('data-')) continue;
				if (name.startsWith(`data-_`)) continue; // private escape hatch
				if (declared.has(name)) continue;
				// Allow other components' part attrs (nested composition).
				if (!name.startsWith(`data-${morfo.kebab}`)) continue;
				issues.push({
					kind: 'undeclared',
					message: `${morfo.kebab}.${part.kebab}: undeclared attr "${name}" emitted on element (not in morfo)`
				});
			}
		}
	}

	return issues;
}

// ── Main ────────────────────────────────────────────────────────────────────

const BASE = process.argv[2] ?? (await probePort(5173, 5180));
if (!BASE) {
	console.error('Could not find a running dev server on 5173-5180.');
	console.error('Start it with `npm run dev` in another terminal.');
	process.exit(2);
}
console.error(`Using dev server at ${BASE}`);

const morfos = await loadMorfos();
if (morfos.length === 0) {
	console.error('No morfos found under src/uix/morfo/components/');
	process.exit(2);
}
console.error(`Loaded ${morfos.length} morfo${morfos.length === 1 ? '' : 's'}`);

const browser = await chromium.launch();
const ctx = await browser.newContext();
const failures: Array<{ morfo: string; issues: Issue[] }> = [];
const skipped: string[] = [];
let checked = 0;

for (const morfo of morfos) {
	const route = routeForMorfo(morfo);
	if (!route) {
		skipped.push(morfo.kebab);
		console.log(`SKIP  ${morfo.kebab.padEnd(24)}  no routed demo under ${routePrefix}`);
		continue;
	}

	checked += 1;
	const page = await ctx.newPage();
	try {
		await page.goto(BASE + route, { waitUntil: 'networkidle', timeout: 20000 });
		await page.waitForTimeout(500);
		const issues = await validateMorfoAgainstDom(page, morfo);
		if (issues.length === 0) {
			console.log(`PASS  ${morfo.kebab.padEnd(24)}  ${route}`);
		} else {
			console.log(`FAIL  ${morfo.kebab.padEnd(24)}  ${route}`);
			issues.forEach((i) => console.log(`      [${i.kind}] ${i.message}`));
			failures.push({ morfo: morfo.kebab, issues });
		}
	} catch (e) {
		console.log(`ERROR ${morfo.kebab.padEnd(24)}  ${(e as Error).message}`);
		failures.push({
			morfo: morfo.kebab,
			issues: [{ kind: 'missing', message: `navigation error: ${(e as Error).message}` }]
		});
	} finally {
		await page.close();
	}
}

await browser.close();

console.log('');
if (checked === 0) {
	console.log(`No routed morfos found under ${routePrefix}.`);
	process.exit(2);
} else if (failures.length === 0) {
	console.log(
		`All ${checked} routed morfo${checked === 1 ? '' : 's'} validate against their demo DOM.`
	);
	if (skipped.length > 0) {
		console.log(`${skipped.length}/${morfos.length} morfos skipped without routed demo.`);
	}
	process.exit(0);
} else {
	const totalIssues = failures.reduce((sum, f) => sum + f.issues.length, 0);
	console.log(
		`${failures.length}/${checked} routed morfos failed (${totalIssues} total issues): ${failures.map((f) => f.morfo).join(', ')}`
	);
	if (skipped.length > 0) {
		console.log(`${skipped.length}/${morfos.length} morfos skipped without routed demo.`);
	}
	process.exit(1);
}