const { shell, clipboard, dialog } = require('electron');
const fs = require('fs');
const path = require('path');
const { spawn } = require('child_process');

function ensureExists(targetPath) {
  try {
    fs.accessSync(targetPath);
    return { ok: true };
  } catch {
    return { ok: false, error: `Path not found:\n${targetPath}` };
  }
}

function ensureWindows() {
  if (process.platform !== 'win32') {
    return { ok: false, error: 'Windows only.' };
  }
  return { ok: true };
}

async function openInExplorer(targetPath) {
  const exists = ensureExists(targetPath);
  if (!exists.ok) return exists;
  const result = await shell.openPath(targetPath);
  if (result) return { ok: false, error: result };
  return { ok: true };
}

// Reasonable cap for the alias used as a wt --title argument and as a
// search pattern. Strips control + reserved chars that would break wt's
// command parser (it splits on `;`).
function sanitizeTitle(s) {
  if (!s) return '';
  return String(s).replace(/[ -;]/g, ' ').trim().slice(0, 80);
}

function isHexColor(s) {
  return typeof s === 'string' && /^#[0-9a-fA-F]{6}$/.test(s);
}

// Per-name cache: `where <name>` is a process spawn we don't want to repeat
// per bookmark-row render. Restart the app if you install a CLI after launch.
const commandAvailableCache = new Map();

function isCommandAvailable(name) {
  if (!name) return true;
  if (commandAvailableCache.has(name)) return commandAvailableCache.get(name);
  if (process.platform !== 'win32') {
    commandAvailableCache.set(name, false);
    return false;
  }
  try {
    const { spawnSync } = require('child_process');
    const result = spawnSync('where', [name], { stdio: 'ignore' });
    const ok = result.status === 0;
    commandAvailableCache.set(name, ok);
    return ok;
  } catch {
    commandAvailableCache.set(name, false);
    return false;
  }
}

// Back-compat shim — preload still exposes isClaudeAvailable, used to disable
// the (now-seeded) Claude action button when the CLI isn't on PATH.
function isClaudeAvailable() {
  return isCommandAvailable('claude');
}

// Calls find-tab.ps1 to locate and focus a Windows Terminal tab whose title
// matches `title`. Resolves to { found: boolean, ... } from the script JSON.
// Returns { found: false } on any spawn/parse failure so callers can fall
// through to launching a fresh tab.
function findAndFocusTab(title) {
  return new Promise((resolve) => {
    const t = sanitizeTitle(title);
    if (!t) { resolve({ found: false, reason: 'no-title' }); return; }
    const scriptPath = path.join(__dirname, 'find-tab.ps1');
    const child = spawn('powershell.exe', [
      '-NoProfile', '-NonInteractive', '-ExecutionPolicy', 'Bypass',
      '-File', scriptPath, '-Title', t,
    ], {
      stdio: ['ignore', 'pipe', 'pipe'],
      windowsHide: true,
    });
    let stdout = '';
    let stderr = '';
    child.stdout.on('data', (d) => { stdout += d.toString(); });
    child.stderr.on('data', (d) => { stderr += d.toString(); });
    child.on('error', () => resolve({ found: false, reason: 'spawn-error' }));
    child.on('close', (code) => {
      if (code !== 0) {
        resolve({ found: false, reason: `exit-${code}`, stderr: stderr.trim() || null });
        return;
      }
      try {
        const parsed = JSON.parse(stdout.trim());
        resolve(parsed || { found: false });
      } catch {
        resolve({ found: false, reason: 'parse-error' });
      }
    });
  });
}

// Spawns wt.exe new-tab with the given title/color/cwd. If trailingArgs is
// non-empty, those args are appended as the commandline that runs in the new
// tab (e.g. ['cmd.exe', '/K', 'claude']). Returns immediately; falls back to
// a plain cmd window on ENOENT (older Windows builds without WT).
function spawnWtNewTab({ targetPath, alias, color, trailingArgs = [] }) {
  const args = ['new-tab', '-d', targetPath];
  const safeTitle = sanitizeTitle(alias);
  if (safeTitle) args.push('--title', safeTitle);
  if (isHexColor(color)) args.push('--tabColor', color);
  for (const a of trailingArgs) args.push(a);

  const child = spawn('wt.exe', args, {
    detached: true,
    stdio: 'ignore',
    windowsHide: false,
  });
  child.on('error', (err) => {
    if (err && err.code === 'ENOENT') spawnCmdFallback({ targetPath, trailingArgs });
  });
  child.unref();
}

// cmd.exe fallback for systems without wt.exe. cmd has no tab/title/color
// concept of its own — best effort: open a new console at the target path,
// optionally running a trailing command. Color is silently dropped.
//
// Trailing args are inspected: if they target powershell.exe (used by the
// Claude launcher), spawn a PowerShell host directly so the user gets the
// same shell they would have gotten through wt.
function spawnCmdFallback({ targetPath, trailingArgs = [] }) {
  const wantsPowerShell = trailingArgs[0] === 'powershell.exe';
  if (wantsPowerShell) {
    const psArgs = ['/c', 'start', '""', '/D', targetPath, ...trailingArgs];
    const child = spawn('cmd.exe', psArgs, {
      detached: true,
      stdio: 'ignore',
      windowsHide: false,
    });
    child.unref();
    return;
  }
  // start "" /D <path> cmd.exe [/K <cmd>]
  // The empty "" after start is the window-title arg — start treats the first
  // quoted token as the title, so omitting it makes start interpret /D as the
  // title and break.
  const args = ['/c', 'start', '""', '/D', targetPath, 'cmd.exe'];
  if (trailingArgs.length > 0) {
    args.push('/K', trailingArgs.filter((a) => !['cmd.exe', '/K'].includes(a)).join(' '));
  }
  const child = spawn('cmd.exe', args, {
    detached: true,
    stdio: 'ignore',
    windowsHide: false,
  });
  child.unref();
}

async function openTerminal({ targetPath, alias, color }) {
  const win = ensureWindows();
  if (!win.ok) return win;
  const exists = ensureExists(targetPath);
  if (!exists.ok) return exists;

  // Try to focus an existing tab first.
  if (alias) {
    const focus = await findAndFocusTab(alias);
    if (focus && focus.found) {
      return { ok: true, focused: true, tabName: focus.tabName };
    }
  }

  spawnWtNewTab({ targetPath, alias, color });
  return { ok: true, focused: false };
}

async function openClaude({ targetPath, alias, color }) {
  const win = ensureWindows();
  if (!win.ok) return win;
  const exists = ensureExists(targetPath);
  if (!exists.ok) return exists;

  if (alias) {
    const focus = await findAndFocusTab(alias);
    if (focus && focus.found) {
      return { ok: true, focused: true, tabName: focus.tabName };
    }
  }

  // -NoExit keeps the PowerShell window open after `claude` exits so the
  // user can read any final output before the tab closes itself.
  spawnWtNewTab({
    targetPath,
    alias,
    color,
    trailingArgs: ['powershell.exe', '-NoExit', '-Command', 'claude'],
  });
  return { ok: true, focused: false };
}

function findSolution(folderPath) {
  try {
    const entries = fs.readdirSync(folderPath, { withFileTypes: true });
    const slns = entries
      .filter((e) => e.isFile() && e.name.toLowerCase().endsWith('.sln'))
      .map((e) => e.name)
      .sort((a, b) => a.localeCompare(b, undefined, { sensitivity: 'base' }));
    if (slns.length === 0) return null;
    return path.join(folderPath, slns[0]);
  } catch {
    return null;
  }
}

function findFileByName(folderPath, name) {
  try {
    const entries = fs.readdirSync(folderPath, { withFileTypes: true });
    const target = String(name || '').toLowerCase();
    if (!target) return null;
    const match = entries.find((e) => e.isFile() && e.name.toLowerCase() === target);
    return match ? path.join(folderPath, match.name) : null;
  } catch {
    return null;
  }
}

// Match by either an exact filename or a simple glob with `*`. When multiple
// files match, the alphabetically first wins so the result is stable across
// runs (mirrors the existing findSolution behavior for *.sln).
function findFileByPattern(folderPath, pattern) {
  if (!pattern) return null;
  if (!String(pattern).includes('*')) return findFileByName(folderPath, pattern);
  try {
    const entries = fs.readdirSync(folderPath, { withFileTypes: true });
    const lowered = String(pattern).toLowerCase();
    const regex = new RegExp(
      '^' + lowered.split(/(\*+)/).map((seg, i) => {
        if (i % 2 === 1) return '.*';
        return seg.replace(/[.+?^${}()|[\]\\]/g, '\\$&');
      }).join('') + '$'
    );
    const matches = entries
      .filter((e) => e.isFile() && regex.test(e.name.toLowerCase()))
      .map((e) => e.name)
      .sort((a, b) => a.localeCompare(b, undefined, { sensitivity: 'base' }));
    if (matches.length === 0) return null;
    return path.join(folderPath, matches[0]);
  } catch {
    return null;
  }
}

function findRedeploy(folderPath) {
  return findFileByName(folderPath, '1ReDeploy.bat');
}

let networkDrivesCache = null;

// Enumerate Windows network-mapped drive letters once. Cached per-process —
// restart the app if the user maps or unmaps drives. Falls back to an empty
// set on any failure so a missing PowerShell or unreadable provider just
// means UNC paths are still detected and mapped drives are treated as local.
function getNetworkDrives() {
  if (networkDrivesCache) return networkDrivesCache;
  networkDrivesCache = new Set();
  if (process.platform !== 'win32') return networkDrivesCache;
  try {
    const { spawnSync } = require('child_process');
    const result = spawnSync('powershell.exe', [
      '-NoProfile', '-NonInteractive', '-Command',
      "Get-PSDrive -PSProvider FileSystem | Where-Object { $_.DisplayRoot } | ForEach-Object { $_.Name }",
    ], { encoding: 'utf8', timeout: 5000 });
    if (result.status === 0 && result.stdout) {
      for (const line of result.stdout.split(/\r?\n/)) {
        const letter = line.trim().toLowerCase();
        if (/^[a-z]$/.test(letter)) networkDrivesCache.add(letter);
      }
    }
  } catch { /* ignore */ }
  return networkDrivesCache;
}

function isNetworkPath(p) {
  if (!p) return false;
  if (/^\\\\/.test(p)) return true; // UNC
  const m = /^([a-zA-Z]):/.exec(p);
  if (!m) return false;
  return getNetworkDrives().has(m[1].toLowerCase());
}

function runRedeploy(targetPath) {
  const win = ensureWindows();
  if (!win.ok) return win;
  const exists = ensureExists(targetPath);
  if (!exists.ok) return exists;
  const batPath = findRedeploy(targetPath);
  if (!batPath) return { ok: false, error: 'No 1ReDeploy.bat found in this folder.' };
  // Open in a new cmd window with /K so the user can see output and any
  // prompts the script needs (typical .bat deploys often pause on completion).
  const child = spawn('cmd.exe', ['/c', 'start', '""', '/D', targetPath, 'cmd.exe', '/K', batPath], {
    detached: true,
    stdio: 'ignore',
    windowsHide: false,
  });
  child.unref();
  return { ok: true, batPath };
}

function openVisualStudio(targetPath) {
  const win = ensureWindows();
  if (!win.ok) return win;
  const exists = ensureExists(targetPath);
  if (!exists.ok) return exists;
  const slnPath = findSolution(targetPath);
  if (!slnPath) return { ok: false, error: 'No .sln file found in this folder.' };
  // Open via shell association — uses whichever Visual Studio version the
  // user has registered for .sln, no need to locate devenv.exe by version.
  const child = spawn('cmd.exe', ['/c', 'start', '""', slnPath], {
    detached: true,
    stdio: 'ignore',
    windowsHide: false,
  });
  child.unref();
  return { ok: true, slnPath };
}

function copyPath(text) {
  if (typeof text !== 'string' || !text) return { ok: false, error: 'No path' };
  clipboard.writeText(text);
  return { ok: true };
}

function inspectFolder(folderPath, actionFiles) {
  const isNetwork = isNetworkPath(folderPath);
  const exists = (() => {
    try { fs.accessSync(folderPath); return true; } catch { return false; }
  })();
  // Per-action requiresFile lookups — renderer passes the patterns it needs
  // resolved (exact filenames or globs like *.sln) so it knows which action
  // buttons to render for this folder.
  const actionMatches = {};
  if (Array.isArray(actionFiles)) {
    for (const pattern of actionFiles) {
      if (typeof pattern !== 'string' || !pattern) continue;
      actionMatches[pattern] = exists ? findFileByPattern(folderPath, pattern) : null;
    }
  }
  // Read .sln + 1ReDeploy.bat regardless of network status — the deploy
  // button is the main reason we'd want the row up for a network share.
  // The renderer separately hides Claude/VS for network paths.
  return {
    exists,
    slnPath: exists ? findSolution(folderPath) : null,
    redeployPath: exists ? findRedeploy(folderPath) : null,
    isNetwork,
    actionMatches,
  };
}

// Generic action runner. Two kinds:
//   terminal  — open Windows Terminal at folder, optionally run `command`
//   detached  — spawn `command` (or matched requiresFile) in a new cmd window
async function runAction(action, ctx) {
  if (!action || typeof action !== 'object') return { ok: false, error: 'Invalid action.' };
  const win = ensureWindows();
  if (!win.ok) return win;
  const exists = ensureExists(ctx.targetPath);
  if (!exists.ok) return exists;

  if (action.kind === 'terminal') {
    if (ctx.alias) {
      const focus = await findAndFocusTab(ctx.alias);
      if (focus && focus.found) return { ok: true, focused: true, tabName: focus.tabName };
    }
    const trailingArgs = action.command
      ? ['powershell.exe', '-NoExit', '-Command', String(action.command)]
      : [];
    spawnWtNewTab({
      targetPath: ctx.targetPath,
      alias: ctx.alias,
      color: ctx.color,
      trailingArgs,
    });
    return { ok: true, focused: false };
  }

  if (action.kind === 'detached') {
    let exe = action.command ? String(action.command) : '';
    const extraArgs = Array.isArray(action.args) ? action.args.map(String) : [];
    if (action.requiresFile) {
      const matched = findFileByPattern(ctx.targetPath, action.requiresFile);
      if (!matched) return { ok: false, error: `${action.requiresFile} not found in folder.` };
      if (!exe) exe = matched;
      else extraArgs.push(matched);
    }
    if (!exe) return { ok: false, error: 'No command configured.' };
    // /K keeps the cmd window open after the command exits (good for .bat
    // scripts whose output you want to inspect); /C closes it (fire-and-forget).
    const switchArg = action.keepOpen ? '/K' : '/C';
    const child = spawn(
      'cmd.exe',
      ['/c', 'start', '""', '/D', ctx.targetPath, 'cmd.exe', switchArg, exe, ...extraArgs],
      { detached: true, stdio: 'ignore', windowsHide: false },
    );
    child.unref();
    return { ok: true };
  }

  if (action.kind === 'open') {
    // Resolve a target file (matched requiresFile, or command treated as a
    // path relative to the folder), then hand off to Windows shell association
    // so whichever app is registered for that extension launches it.
    let target = null;
    if (action.requiresFile) {
      target = findFileByPattern(ctx.targetPath, action.requiresFile);
      if (!target) return { ok: false, error: `${action.requiresFile} not found in folder.` };
    } else if (action.command) {
      target = path.isAbsolute(action.command)
        ? action.command
        : path.join(ctx.targetPath, action.command);
    } else {
      return { ok: false, error: 'No file or command configured for open action.' };
    }
    const result = await shell.openPath(target);
    if (result) return { ok: false, error: result };
    return { ok: true };
  }

  return { ok: false, error: `Unknown action kind: ${action.kind || '(none)'}` };
}

async function pickFolder() {
  const result = await dialog.showOpenDialog({
    title: 'Pick a folder to bookmark',
    properties: ['openDirectory'],
  });
  if (result.canceled || !result.filePaths || result.filePaths.length === 0) return null;
  return result.filePaths[0];
}

module.exports = {
  openInExplorer,
  openTerminal,
  openClaude,
  openVisualStudio,
  runRedeploy,
  runAction,
  copyPath,
  inspectFolder,
  findSolution,
  findRedeploy,
  findFileByName,
  findFileByPattern,
  isNetworkPath,
  pickFolder,
  isClaudeAvailable,
  isCommandAvailable,
};