import { app } from 'electron';
import fs from 'fs';
import path from 'path';
import log from 'electron-log';
import type {
  AutomationScript,
  ScriptMetaItem,
  ScriptsMeta,
  ScriptSaveInput,
} from '../../types/script-types';

const META_FILENAME = 'scripts.meta.json';

function getScriptsDir(): string {
  return app.isPackaged
    ? path.join(__dirname, 'scripts')
    : path.join(process.cwd(), 'electron/scripts');
}

function ensureScriptsDir(): void {
  const dir = getScriptsDir();
  if (!fs.existsSync(dir)) {
    fs.mkdirSync(dir, { recursive: true });
  }
}

function getMetaPath(): string {
  return path.join(getScriptsDir(), META_FILENAME);
}

function readMeta(): ScriptsMeta {
  const metaPath = getMetaPath();
  if (!fs.existsSync(metaPath)) {
    return { scripts: [] };
  }
  try {
    const raw = fs.readFileSync(metaPath, 'utf-8');
    const parsed = JSON.parse(raw);
    if (parsed && Array.isArray(parsed.scripts)) {
      return parsed as ScriptsMeta;
    }
  } catch (err) {
    log.warn('[script-store-service] Failed to read meta:', err);
  }
  return { scripts: [] };
}

function writeMeta(meta: ScriptsMeta): void {
  ensureScriptsDir();
  const metaPath = getMetaPath();
  fs.writeFileSync(metaPath, JSON.stringify(meta, null, 2), 'utf-8');
}

function sanitizeFilename(name: string): string {
  return name
    .toLowerCase()
    .replace(/[^a-z0-9\u4e00-\u9fa5]+/g, '-')
    .replace(/^-+|-+$/g, '')
    || 'script';
}

function generateUniqueFilename(name: string, existingNames: Set<string>): string {
  const base = sanitizeFilename(name);
  let filename = `${base}.mjs`;
  let counter = 1;
  while (existingNames.has(filename)) {
    filename = `${base}-${counter}.mjs`;
    counter++;
  }
  return filename;
}

function seedScripts(): void {
  const scriptsDir = getScriptsDir();
  const metaPath = getMetaPath();

  if (fs.existsSync(metaPath)) {
    return;
  }

  if (!fs.existsSync(scriptsDir)) {
    log.info('[script-store-service] Scripts directory does not exist, skipping seed.');
    return;
  }

  const meta: ScriptsMeta = { scripts: [] };
  const scriptFiles = fs.readdirSync(scriptsDir).filter((f) => f.endsWith('.mjs'));

  for (const file of scriptFiles) {
    try {
      const name = file.replace(/\.mjs$/, '');
      const now = new Date().toISOString();
      meta.scripts.push({
        id: `seed-${name}`,
        name,
        description: '',
        filename: file,
        enabled: true,
        channel: '',
        createdAt: now,
        updatedAt: now,
      });
    } catch (err) {
      log.warn('[script-store-service] Failed to seed script', file, err);
    }
  }

  writeMeta(meta);
  log.info('[script-store-service] Seeded scripts:', meta.scripts.length);
}

export function initScriptStoreService(): void {
  ensureScriptsDir();
  seedScripts();
}

export function listScripts(): AutomationScript[] {
  const meta = readMeta();
  return meta.scripts
    .map((item) => enrichWithCode(item))
    .sort((a, b) => new Date(b.updatedAt).getTime() - new Date(a.updatedAt).getTime());
}

export function getScript(id: string): AutomationScript | null {
  const meta = readMeta();
  const item = meta.scripts.find((s) => s.id === id);
  if (!item) return null;
  return enrichWithCode(item);
}

export function getScriptPathById(id: string): string | null {
  const meta = readMeta();
  const item = meta.scripts.find((s) => s.id === id);
  if (!item) return null;
  return path.join(getScriptsDir(), item.filename);
}

export function saveScript(input: ScriptSaveInput): AutomationScript {
  const meta = readMeta();
  const scriptsDir = getScriptsDir();
  const existingNames = new Set(meta.scripts.map((s) => s.filename));
  const now = new Date().toISOString();

  if (input.id) {
    const index = meta.scripts.findIndex((s) => s.id === input.id);
    if (index >= 0) {
      const existing = meta.scripts[index];
      const filePath = path.join(scriptsDir, existing.filename);
      fs.writeFileSync(filePath, input.code, 'utf-8');
      meta.scripts[index] = {
        ...existing,
        name: input.name,
        description: input.description,
        channel: input.channel,
        enabled: input.enabled,
        updatedAt: now,
      };
      writeMeta(meta);
      return enrichWithCode(meta.scripts[index]);
    }
  }

  const filename = generateUniqueFilename(input.name, existingNames);
  const filePath = path.join(scriptsDir, filename);
  fs.writeFileSync(filePath, input.code, 'utf-8');

  const id = `script-${Date.now()}-${Math.random().toString(36).slice(2, 7)}`;
  const item: ScriptMetaItem = {
    id,
    name: input.name,
    description: input.description,
    filename,
    enabled: input.enabled,
    channel: input.channel,
    createdAt: now,
    updatedAt: now,
  };

  meta.scripts.push(item);
  writeMeta(meta);
  return enrichWithCode(item);
}

export function deleteScript(id: string): boolean {
  const meta = readMeta();
  const index = meta.scripts.findIndex((s) => s.id === id);
  if (index === -1) return false;

  const item = meta.scripts[index];
  const filePath = path.join(getScriptsDir(), item.filename);
  if (fs.existsSync(filePath)) {
    try {
      fs.unlinkSync(filePath);
    } catch (err) {
      log.warn('[script-store-service] Failed to delete script file:', err);
    }
  }

  meta.scripts.splice(index, 1);
  writeMeta(meta);
  return true;
}

export function toggleScript(id: string, enabled: boolean): boolean {
  const meta = readMeta();
  const index = meta.scripts.findIndex((s) => s.id === id);
  if (index === -1) return false;

  meta.scripts[index].enabled = enabled;
  meta.scripts[index].updatedAt = new Date().toISOString();
  writeMeta(meta);
  return true;
}

export function updateLastRun(id: string, lastRun: NonNullable<AutomationScript['lastRun']>): boolean {
  const meta = readMeta();
  const index = meta.scripts.findIndex((s) => s.id === id);
  if (index === -1) return false;

  meta.scripts[index].lastRun = lastRun;
  meta.scripts[index].updatedAt = new Date().toISOString();
  writeMeta(meta);
  return true;
}

function enrichWithCode(item: ScriptMetaItem): AutomationScript {
  const scriptsDir = getScriptsDir();
  const filePath = path.join(scriptsDir, item.filename);
  let code = '';
  try {
    if (fs.existsSync(filePath)) {
      code = fs.readFileSync(filePath, 'utf-8');
    }
  } catch (err) {
    log.warn('[script-store-service] Failed to read script file:', err);
  }
  return {
    ...item,
    code,
  } as AutomationScript;
}