/**
 * Skill Config Utilities
 * Direct read/write access to skill configuration in ~/.openclaw/openclaw.json
 * This bypasses the Gateway RPC for faster and more reliable config updates.
 *
 * All file I/O uses async fs/promises to avoid blocking the main thread.
 */
import { spawn } from 'child_process';
import { app } from 'electron';
import { readFile, writeFile, access, mkdir, readdir, constants, cp } from 'fs/promises';
import { existsSync } from 'fs';
import { join } from 'path';
import { getOpenClawConfigDir, ensureDir, getResourcesDir } from './paths';

const OPENCLAW_CONFIG_PATH = join(getOpenClawConfigDir(), 'openclaw.json');
const SKILLS_DIR = join(getOpenClawConfigDir(), 'skills');

interface SkillEntry {
  enabled?: boolean;
  apiKey?: string;
  env?: Record<string, string>;
}

interface OpenClawConfig {
  skills?: {
    entries?: Record<string, SkillEntry>;
    [key: string]: unknown;
  };
  [key: string]: unknown;
}

interface PreinstalledSkillSpec {
  slug: string;
  version?: string;
  autoEnable?: boolean;
}

interface PreinstalledManifest {
  skills?: PreinstalledSkillSpec[];
}

interface PreinstalledLockEntry {
  slug: string;
  version?: string;
}

interface PreinstalledLockFile {
  skills?: PreinstalledLockEntry[];
}

interface PreinstalledMarker {
  source: 'clawx-preinstalled';
  slug: string;
  version: string;
  installedAt: string;
}

export interface SkillConfigRecord {
  slug?: string;
  name?: string;
  description?: string;
  enabled?: boolean;
  icon?: string;
  version?: string;
  author?: string;
  config?: Record<string, unknown>;
  apiKey?: string;
  env?: Record<string, string>;
  isCore?: boolean;
  isBundled?: boolean;
  source?: string;
  baseDir?: string;
  filePath?: string;
}

interface ParsedFrontmatter {
  name?: string;
  description?: string;
  version?: string;
  author?: string;
  icon?: string;
  [key: string]: unknown;
}

const PREINSTALLED_MANIFEST_NAME = 'preinstalled-manifest.json';
const PREINSTALLED_MARKER_NAME = '.clawx-preinstalled.json';

async function fileExists(p: string): Promise<boolean> {
  try {
    await access(p, constants.F_OK);
    return true;
  } catch {
    return false;
  }
}

/**
 * Read the current OpenClaw config
 */
async function readConfig(): Promise<OpenClawConfig> {
  if (!(await fileExists(OPENCLAW_CONFIG_PATH))) {
    return {};
  }
  try {
    const raw = await readFile(OPENCLAW_CONFIG_PATH, 'utf-8');
    return JSON.parse(raw) as OpenClawConfig;
  } catch (err) {
    console.error('Failed to read openclaw config:', err);
    return {};
  }
}

/**
 * Write the OpenClaw config
 */
async function writeConfig(config: OpenClawConfig): Promise<void> {
  const json = JSON.stringify(config, null, 2);
  await writeFile(OPENCLAW_CONFIG_PATH, json, 'utf-8');
}

async function setSkillsEnabled(skillKeys: string[], enabled: boolean): Promise<void> {
  if (skillKeys.length === 0) {
    return;
  }

  const config = await readConfig();
  if (!config.skills) {
    config.skills = {};
  }
  if (!config.skills.entries) {
    config.skills.entries = {};
  }

  for (const skillKey of skillKeys) {
    const entry = config.skills.entries[skillKey] || {};
    entry.enabled = enabled;
    config.skills.entries[skillKey] = entry;
  }

  await writeConfig(config);
}

/**
 * Parse YAML-like frontmatter from markdown content.
 * Extracts key: value pairs from the --- delimited block at the start.
 */
function parseFrontmatter(content: string): ParsedFrontmatter {
  const match = content.match(/^---\s*\n([\s\S]*?)\n---/);
  if (!match) {
    return {};
  }

  const frontmatter = match[1];
  const result: ParsedFrontmatter = {};

  for (const line of frontmatter.split('\n')) {
    const trimmed = line.trim();
    if (!trimmed || trimmed.startsWith('#')) {
      continue;
    }

    // Match key: value (simple scalar values only)
    const colonIndex = trimmed.indexOf(':');
    if (colonIndex === -1) {
      continue;
    }

    const key = trimmed.slice(0, colonIndex).trim();
    let value = trimmed.slice(colonIndex + 1).trim();

    // Remove surrounding quotes
    if ((value.startsWith('"') && value.endsWith('"')) ||
        (value.startsWith("'") && value.endsWith("'"))) {
      value = value.slice(1, -1);
    }

    if (key) {
      result[key] = value;
    }
  }

  return result;
}

async function readPreinstalledManifest(): Promise<PreinstalledSkillSpec[]> {
  const candidates = [
    join(getResourcesDir(), 'skills', PREINSTALLED_MANIFEST_NAME),
    join(process.cwd(), 'resources', 'skills', PREINSTALLED_MANIFEST_NAME),
  ];

  const manifestPath = candidates.find((candidate) => existsSync(candidate));
  if (!manifestPath) {
    return [];
  }

  try {
    const raw = await readFile(manifestPath, 'utf-8');
    const parsed = JSON.parse(raw) as PreinstalledManifest;
    if (!Array.isArray(parsed.skills)) {
      return [];
    }
    return parsed.skills.filter((skill): skill is PreinstalledSkillSpec => Boolean(skill?.slug));
  } catch (error) {
    console.warn('Failed to read preinstalled skills manifest:', error);
    return [];
  }
}

function resolvePreinstalledSkillsSourceRoot(): string | null {
  const candidates = [
    join(getResourcesDir(), 'preinstalled-skills'),
    join(process.cwd(), 'build', 'preinstalled-skills'),
    join(__dirname, '../../build/preinstalled-skills'),
  ];

  const root = candidates.find((candidate) => existsSync(candidate));
  return root || null;
}

async function preparePreinstalledSkillsSourceRootForDev(): Promise<string | null> {
  const existingRoot = resolvePreinstalledSkillsSourceRoot();
  if (existingRoot) {
    return existingRoot;
  }

  if (app.isPackaged) {
    return null;
  }

  const appRoot = app.getAppPath();
  const scriptPath = join(appRoot, 'scripts', 'bundle-preinstalled-skills.mjs');
  const zxBinName = process.platform === 'win32' ? 'zx.cmd' : 'zx';
  const zxPath = join(appRoot, 'node_modules', '.bin', zxBinName);

  if (!existsSync(scriptPath) || !existsSync(zxPath)) {
    console.warn('Preinstalled skills bundle missing and dev prepare tooling is unavailable.');
    return null;
  }

  console.info('Preinstalled skills bundle missing; preparing it on startup for dev mode...');

  await new Promise<void>((resolve, reject) => {
    const child = spawn(zxPath, [scriptPath], {
      cwd: appRoot,
      env: {
        ...process.env,
        CI: 'true',
        FORCE_COLOR: '0',
      },
      stdio: 'pipe',
      windowsHide: true,
    });

    let stderr = '';

    child.stdout.on('data', (chunk) => {
      console.info(`[preinstalled-skills] ${String(chunk).trim()}`);
    });

    child.stderr.on('data', (chunk) => {
      const text = String(chunk).trim();
      stderr += text;
      if (text) {
        console.warn(`[preinstalled-skills] ${text}`);
      }
    });

    child.on('error', (error) => reject(error));
    child.on('close', (code) => {
      if (code === 0) {
        resolve();
        return;
      }
      reject(new Error(stderr || `bundle-preinstalled-skills exited with code ${code ?? 'unknown'}`));
    });
  });

  return resolvePreinstalledSkillsSourceRoot();
}

async function readPreinstalledLockVersions(sourceRoot: string): Promise<Map<string, string>> {
  const lockPath = join(sourceRoot, '.preinstalled-lock.json');
  if (!(await fileExists(lockPath))) {
    return new Map();
  }

  try {
    const raw = await readFile(lockPath, 'utf-8');
    const parsed = JSON.parse(raw) as PreinstalledLockFile;
    const versions = new Map<string, string>();

    for (const entry of parsed.skills || []) {
      const slug = entry.slug?.trim();
      const version = entry.version?.trim();
      if (slug && version) {
        versions.set(slug, version);
      }
    }

    return versions;
  } catch (error) {
    console.warn('Failed to read preinstalled skills lock file:', error);
    return new Map();
  }
}

async function tryReadPreinstalledMarker(markerPath: string): Promise<PreinstalledMarker | null> {
  if (!(await fileExists(markerPath))) {
    return null;
  }

  try {
    const raw = await readFile(markerPath, 'utf-8');
    const parsed = JSON.parse(raw) as PreinstalledMarker;
    if (!parsed?.slug || !parsed?.version) {
      return null;
    }
    return parsed;
  } catch {
    return null;
  }
}

/**
 * Scan the skills directory and parse SKILL.md frontmatter for each skill.
 */
async function scanSkillsDirectory(): Promise<Record<string, SkillConfigRecord>> {
  const result: Record<string, SkillConfigRecord> = {};

  if (!(await fileExists(SKILLS_DIR))) {
    return result;
  }

  let entries: string[];
  try {
    entries = await readdir(SKILLS_DIR, { withFileTypes: true });
  } catch {
    return result;
  }

  for (const dirent of entries) {
    if (!dirent.isDirectory()) {
      continue;
    }

    const slug = dirent.name;
    const skillDir = join(SKILLS_DIR, slug);
    const skillMdPath = join(skillDir, 'SKILL.md');
    const markerPath = join(skillDir, PREINSTALLED_MARKER_NAME);

    if (!(await fileExists(skillMdPath))) {
      continue;
    }

    let content: string;
    try {
      content = await readFile(skillMdPath, 'utf-8');
    } catch {
      continue;
    }

    const frontmatter = parseFrontmatter(content);
    const preinstalledMarker = await tryReadPreinstalledMarker(markerPath);

    result[slug] = {
      slug,
      name: frontmatter.name || slug,
      description: frontmatter.description,
      version: frontmatter.version,
      author: frontmatter.author,
      icon: frontmatter.icon,
      baseDir: skillDir,
      filePath: skillMdPath,
      source: preinstalledMarker ? 'openclaw-bundled' : 'openclaw-managed',
      isBundled: Boolean(preinstalledMarker),
    };
  }

  return result;
}

/**
 * Get skill config (raw entry from config file)
 */
export async function getSkillConfig(skillKey: string): Promise<SkillEntry | undefined> {
  const config = await readConfig();
  return config.skills?.entries?.[skillKey];
}

/**
 * Update skill config (apiKey, env, and enabled)
 */
export async function updateSkillConfig(
  skillKey: string,
  updates: { apiKey?: string; env?: Record<string, string>; enabled?: boolean }
): Promise<{ success: boolean; error?: string }> {
  try {
    const config = await readConfig();

    // Ensure skills.entries exists
    if (!config.skills) {
      config.skills = {};
    }
    if (!config.skills.entries) {
      config.skills.entries = {};
    }

    // Get or create skill entry
    const entry = config.skills.entries[skillKey] || {};

    // Update apiKey
    if (updates.apiKey !== undefined) {
      const trimmed = updates.apiKey.trim();
      if (trimmed) {
        entry.apiKey = trimmed;
      } else {
        delete entry.apiKey;
      }
    }

    // Update env
    if (updates.env !== undefined) {
      const newEnv: Record<string, string> = {};

      for (const [key, value] of Object.entries(updates.env)) {
        const trimmedKey = key.trim();
        if (!trimmedKey) continue;

        const trimmedVal = value.trim();
        if (trimmedVal) {
          newEnv[trimmedKey] = trimmedVal;
        }
      }

      if (Object.keys(newEnv).length > 0) {
        entry.env = newEnv;
      } else {
        delete entry.env;
      }
    }

    // Update enabled
    if (updates.enabled !== undefined) {
      entry.enabled = updates.enabled;
    }

    // Save entry back
    config.skills.entries[skillKey] = entry;

    await writeConfig(config);
    return { success: true };
  } catch (err) {
    console.error('Failed to update skill config:', err);
    return { success: false, error: String(err) };
  }
}

/**
 * Get all skill configs (for syncing to frontend)
 * Merges directory-scan metadata with config file entries.
 */
export async function getAllSkillConfigs(): Promise<Record<string, SkillConfigRecord>> {
  const [config, scanned] = await Promise.all([readConfig(), scanSkillsDirectory()]);
  const entries = config.skills?.entries || {};

  // Start with scanned directory data
  const result: Record<string, SkillConfigRecord> = { ...scanned };

  // Merge config entries into scanned data (or create records for config-only skills)
  for (const [slug, entry] of Object.entries(entries)) {
    if (result[slug]) {
      // Merge config values into scanned metadata
      result[slug] = {
        ...result[slug],
        enabled: entry.enabled,
        apiKey: entry.apiKey,
        env: entry.env,
      };
    } else {
      // Config-only skill (no directory found)
      result[slug] = {
        slug,
        name: slug,
        enabled: entry.enabled,
        apiKey: entry.apiKey,
        env: entry.env,
      };
    }
  }

  return result;
}

/**
 * Built-in skills bundled with zn-ai that should be pre-deployed to
 * ~/.openclaw/skills/ on first launch. These come from the app resources
 * and are available in both dev and packaged builds.
 */
const BUILTIN_SKILLS = [] as const;

/**
 * Ensure built-in skills are deployed to ~/.openclaw/skills/<slug>/.
 * Skips any skill that already has a SKILL.md present (idempotent).
 * Runs at app startup; all errors are logged and swallowed so they never
 * block the normal startup flow.
 */
export async function ensureBuiltinSkillsInstalled(): Promise<void> {
  const skillsRoot = join(getOpenClawConfigDir(), 'skills');
  ensureDir(skillsRoot);

  for (const { slug, sourceExtension } of BUILTIN_SKILLS) {
    const targetDir = join(skillsRoot, slug);
    const targetManifest = join(targetDir, 'SKILL.md');

    if (existsSync(targetManifest)) {
      continue; // already installed
    }

    // In zn-ai, built-in skills would be in app resources or node_modules
    // This is a placeholder path pattern; adjust as needed for your build layout
    const sourceDir = join(process.resourcesPath || process.cwd(), 'skills', sourceExtension, slug);

    if (!existsSync(join(sourceDir, 'SKILL.md'))) {
      console.warn(`Built-in skill source not found, skipping: ${sourceDir}`);
      continue;
    }

    try {
      await mkdir(targetDir, { recursive: true });
      await cp(sourceDir, targetDir, { recursive: true, force: true });
      console.info(`Installed built-in skill: ${slug} -> ${targetDir}`);
    } catch (error) {
      console.warn(`Failed to install built-in skill ${slug}:`, error);
    }
  }
}

/**
 * Ensure third-party preinstalled skills from the ClawX-compatible manifest
 * are copied into ~/.openclaw/skills in an idempotent, non-destructive way.
 */
export async function ensurePreinstalledSkillsInstalled(): Promise<void> {
  const skills = await readPreinstalledManifest();
  if (skills.length === 0) {
    return;
  }

  const sourceRoot = await preparePreinstalledSkillsSourceRootForDev();
  if (!sourceRoot) {
    console.warn('Preinstalled skills source root not found; skipping preinstall.');
    return;
  }

  const lockVersions = await readPreinstalledLockVersions(sourceRoot);
  const targetRoot = join(getOpenClawConfigDir(), 'skills');
  await mkdir(targetRoot, { recursive: true });

  const toEnable: string[] = [];

  for (const spec of skills) {
    const sourceDir = join(sourceRoot, spec.slug);
    const sourceManifest = join(sourceDir, 'SKILL.md');
    if (!(await fileExists(sourceManifest))) {
      console.warn(`Preinstalled skill source missing SKILL.md, skipping: ${sourceDir}`);
      continue;
    }

    const targetDir = join(targetRoot, spec.slug);
    const targetManifest = join(targetDir, 'SKILL.md');
    const markerPath = join(targetDir, PREINSTALLED_MARKER_NAME);
    const desiredVersion = lockVersions.get(spec.slug)
      || (spec.version || 'unknown').trim()
      || 'unknown';
    const marker = await tryReadPreinstalledMarker(markerPath);

    if (existsSync(targetManifest)) {
      if (!marker) {
        continue;
      }
      if (marker.version === desiredVersion) {
        continue;
      }
      continue;
    }

    try {
      await mkdir(targetDir, { recursive: true });
      await cp(sourceDir, targetDir, { recursive: true, force: true });

      const markerPayload: PreinstalledMarker = {
        source: 'clawx-preinstalled',
        slug: spec.slug,
        version: desiredVersion,
        installedAt: new Date().toISOString(),
      };
      await writeFile(markerPath, `${JSON.stringify(markerPayload, null, 2)}\n`, 'utf-8');

      if (spec.autoEnable) {
        toEnable.push(spec.slug);
      }

      console.info(`Installed preinstalled skill: ${spec.slug} -> ${targetDir}`);
    } catch (error) {
      console.warn(`Failed to install preinstalled skill ${spec.slug}:`, error);
    }
  }

  if (toEnable.length > 0) {
    try {
      await setSkillsEnabled(toEnable, true);
    } catch (error) {
      console.warn('Failed to auto-enable preinstalled skills:', error);
    }
  }
}