import fs from 'node:fs';
import path from 'node:path';
import { createRequire } from 'node:module';
import { fileURLToPath } from 'node:url';

const projectRoot = path.resolve(path.dirname(fileURLToPath(import.meta.url)), '..');
const sourceRoot = path.resolve(process.env.XIAOSHU_UNIAPP_ROOT || path.join(projectRoot, '..', 'xiaoshu-uniapp'));
const sourceRequire = createRequire(path.join(sourceRoot, 'package.json'));
const JSON5 = sourceRequire('json5');
const { parseComponent } = sourceRequire('vue-template-compiler');
const parser = sourceRequire('@babel/parser');
const pagesJson = JSON5.parse(fs.readFileSync(path.join(sourceRoot, 'pages.json'), 'utf8'));
const pages = [
  ...(pagesJson.pages || []).map((page) => page.path),
  ...(pagesJson.subPackages || pagesJson.subpackages || []).flatMap((group) =>
    (group.pages || []).map((page) => `${group.root}/${page.path}`),
  ),
];

const rows = pages.map((pagePath) => inspectPage(pagePath));
const actions = [...new Set(rows.flatMap((page) => page.apiCalls.map((call) => call.action)).filter((action) => action !== '<dynamic>'))].sort();
const externalCalls = [...new Set(rows.flatMap((page) => page.externalCalls.map((call) => `${call.service}.${call.operation}`)))].sort();
const outputPath = path.join(projectRoot, 'projects/xiaoshu-mobile/src/app/core/source-parity.generated.ts');
const output = `// Generated by npm run parity:generate. Do not edit manually.\n` +
  `export const SOURCE_PAGE_PARITY = ${JSON.stringify(rows, null, 2)} as const;\n\n` +
  `export const SOURCE_API_ACTIONS = ${JSON.stringify(actions, null, 2)} as const;\n\n` +
  `export const SOURCE_EXTERNAL_CALLS = ${JSON.stringify(externalCalls, null, 2)} as const;\n`;

if (process.argv.includes('--check')) {
  const current = fs.existsSync(outputPath) ? fs.readFileSync(outputPath, 'utf8') : '';
  if (current !== output) {
    console.error('Source parity manifest is stale. Run npm run parity:generate.');
    process.exitCode = 1;
  }
} else {
  fs.writeFileSync(outputPath, output);
  console.log(`Generated ${rows.length} pages and ${actions.length} API actions.`);
}

function inspectPage(pagePath) {
  const file = path.join(sourceRoot, `${pagePath}.vue`);
  const source = fs.readFileSync(file, 'utf8');
  const descriptor = parseComponent(source, { pad: 'line' });
  const script = descriptor.script?.content || '';
  const ast = parser.parse(script, { sourceType: 'module', plugins: ['optionalChaining', 'objectRestSpread'] });
  const apiCalls = [];
  const externalCalls = [];
  const methods = [];
  const navigations = [];
  walk(ast, (node) => {
    if (node.type === 'ObjectMethod' && node.key?.type === 'Identifier') methods.push(node.key.name);
    if (node.type !== 'CallExpression') return;
    const callee = memberName(node.callee);
    const first = node.arguments?.[0];
    const literal = first?.type === 'StringLiteral' ? first.value : '<dynamic>';
    if (/(?:uni\.\$u\.http|this\.\$u\.http)\.(get|post)$/.test(callee)) {
      apiCalls.push({ method: callee.endsWith('.post') ? 'post' : 'get', action: literal, line: node.loc?.start.line || 0 });
    }
    if (/^httpApi\.[A-Za-z0-9_]+$/.test(callee)) {
      externalCalls.push({ service: 'bytedesk', operation: callee.slice('httpApi.'.length), line: node.loc?.start.line || 0 });
    }
    if (/(?:navigateTo|redirectTo|switchTab|reLaunch|\.route)$/.test(callee)) {
      navigations.push({ call: callee, target: literal, line: node.loc?.start.line || 0 });
    }
  });
  return {
    path: pagePath,
    sourceFile: `${pagePath}.vue`,
    apiCalls: unique(apiCalls, (item) => `${item.method}:${item.action}:${item.line}`),
    externalCalls: unique(externalCalls, (item) => `${item.service}:${item.operation}:${item.line}`),
    methods: [...new Set(methods)],
    navigations,
  };
}

function memberName(node) {
  if (!node) return '';
  if (node.type === 'Identifier') return node.name;
  if (node.type === 'ThisExpression') return 'this';
  if (node.type === 'MemberExpression' || node.type === 'OptionalMemberExpression') {
    const property = node.computed ? node.property?.value ?? memberName(node.property) : memberName(node.property);
    return `${memberName(node.object)}.${property}`;
  }
  return '';
}

function walk(node, visit) {
  if (!node || typeof node !== 'object') return;
  visit(node);
  for (const [key, value] of Object.entries(node)) {
    if (['loc', 'start', 'end', 'extra'].includes(key)) continue;
    if (Array.isArray(value)) value.forEach((entry) => walk(entry, visit));
    else if (value?.type) walk(value, visit);
  }
}

function unique(items, key) {
  return [...new Map(items.map((item) => [key(item), item])).values()];
}