import assert from 'node:assert/strict';
import { readdirSync, readFileSync, statSync } from 'node:fs';
import path from 'node:path';
import test from 'node:test';
import valueParser from 'postcss-value-parser';
import vueTemplateCompiler from 'vue-template-compiler';

const roots = ['pages', 'components'];
const extraFiles = ['App.vue', 'uni.scss'];
const styleExtensions = new Set(['.css', '.scss']);

function listFiles(dir) {
  const result = [];
  for (const entry of readdirSync(dir)) {
    const fullPath = path.join(dir, entry);
    const stat = statSync(fullPath);
    if (stat.isDirectory()) {
      result.push(...listFiles(fullPath));
    } else {
      result.push(fullPath);
    }
  }
  return result;
}

function stripCssCommentsPreserveOffsets(source) {
  let output = '';
  let quote = null;

  for (let i = 0; i < source.length; i += 1) {
    const char = source[i];
    const next = source[i + 1];

    if (quote) {
      output += char;
      if (char === '\\') {
        i += 1;
        output += source[i] || '';
      } else if (char === quote) {
        quote = null;
      }
      continue;
    }

    if (char === '"' || char === "'") {
      quote = char;
      output += char;
      continue;
    }

    if (char === '/' && next === '*') {
      output += '  ';
      i += 2;
      while (i < source.length && !(source[i] === '*' && source[i + 1] === '/')) {
        output += source[i] === '\n' ? '\n' : ' ';
        i += 1;
      }
      output += '  ';
      i += 1;
      continue;
    }

    if (char === '/' && next === '/') {
      output += '  ';
      i += 2;
      while (i < source.length && source[i] !== '\n') {
        output += ' ';
        i += 1;
      }
      if (source[i] === '\n') {
        output += '\n';
      }
      continue;
    }

    output += char;
  }

  return output;
}

function lineForOffset(source, offset) {
  return source.slice(0, offset).split('\n').length;
}

function collectRootStaticStyleUrls(filePath, styleSource, sourceOffset = 0, originalSource = styleSource) {
  const stripped = stripCssCommentsPreserveOffsets(styleSource);
  const findings = [];

  valueParser(stripped).walk((node) => {
    if (node.type !== 'function' || node.value.toLowerCase() !== 'url') {
      return;
    }

    const url = valueParser.stringify(node.nodes).trim().replace(/^['"]|['"]$/g, '');
    if (!url.startsWith('/static/')) {
      return;
    }

    findings.push({
      filePath,
      line: lineForOffset(originalSource, sourceOffset + node.sourceIndex),
      url,
    });
  });

  return findings;
}

function styleSourcesForFile(filePath) {
  const source = readFileSync(filePath, 'utf8');
  if (filePath.endsWith('.vue')) {
    const descriptor = vueTemplateCompiler.parseComponent(source);
    return descriptor.styles.map((style) => ({
      source: style.content,
      sourceOffset: style.start,
      originalSource: source,
    }));
  }

  return [{ source, sourceOffset: 0, originalSource: source }];
}

test('style url() references do not use H5-root /static paths', () => {
  const files = [
    ...roots.flatMap((root) => listFiles(root)),
    ...extraFiles,
  ].filter((filePath) => filePath.endsWith('.vue') || styleExtensions.has(path.extname(filePath)));

  const findings = files.flatMap((filePath) =>
    styleSourcesForFile(filePath).flatMap(({ source, sourceOffset, originalSource }) =>
      collectRootStaticStyleUrls(filePath, source, sourceOffset, originalSource)
    )
  );

  assert.deepEqual(
    findings,
    [],
    `style url() must use relative static paths so H5 /h5 deployments do not request site-root assets:\n${
      findings.map((item) => `${item.filePath}:${item.line} ${item.url}`).join('\n')
    }`
  );
});