import crypto from 'node:crypto';
import fs from 'node:fs';
import os from 'node:os';
import path from 'node:path';
import { spawn } from 'node:child_process';
import { normalizeDeliveryRelativePath } from './mindspace-delivery-contract.mjs';
import {
  expandHome,
  resolveCursorAgentBin as resolveSharedCursorAgentBin,
} from './cursor-agent-launch.mjs';

export const HELP_ESCALATION_ACK_TEXT =
  '已转工程师处理，请稍候。处理完成后会通知你结果。';

export const HELP_ESCALATION_DETAILS_PROMPT = [
  '请补充具体问题后再发送，例如：',
  'help 我的页面 tang-dynasty 打不开',
  'help 聊天一直卡住',
  'help 定时任务没有推送',
  '',
  '工程师需要知道：出了什么问题、相关页面或链接、你期望的结果。',
].join('\n');

export const HELP_ESCALATION_STATUS = {
  QUEUED: 'queued',
  RUNNING: 'running',
  SUCCEEDED: 'succeeded',
  FAILED: 'failed',
};

const HELP_INTENT_PATTERNS = [
  /^help(?:\s+|$)/i,
  /^\/help(?:\s+|$)/i,
  /^帮助(?:\s+|$)/u,
  /^人工帮助(?:\s+|$)/u,
  /^找工程师(?:\s+|$)/u,
  /^升级处理(?:\s+|$)/u,
  /^工程师介入(?:\s+|$)/u,
];

const HELP_COMMAND_PREFIX_PATTERNS = [
  /^help[,，]?\s*/i,
  /^\/help\s*/i,
  /^帮助\s*/u,
  /^人工帮助\s*/u,
  /^找工程师\s*/u,
  /^升级处理\s*/u,
  /^工程师介入\s*/u,
];

function envFlag(value, fallback = false) {
  const raw = String(value ?? '').trim().toLowerCase();
  if (!raw) return fallback;
  return ['1', 'true', 'yes', 'on'].includes(raw);
}

function nowMs() {
  return Date.now();
}

export function extractHelpEscalationText(input) {
  if (typeof input === 'string') return input.trim();
  if (!input || typeof input !== 'object') return '';
  if (typeof input.text === 'string') return input.text.trim();
  if (Array.isArray(input.content)) {
    return input.content
      .map((item) => {
        if (!item || typeof item !== 'object') return '';
        if (item.type === 'text') return String(item.text ?? '').trim();
        return '';
      })
      .filter(Boolean)
      .join('\n')
      .trim();
  }
  return String(input.value ?? '').trim();
}

export function normalizeHelpEscalationCommandText(text) {
  const normalized = String(text ?? '').trim();
  if (!normalized) return '';
  const blocks = normalized.split(/\n\n+/);
  const lastBlock = (blocks[blocks.length - 1] ?? normalized).trim();
  const candidate = lastBlock || normalized;
  return candidate.replace(/^help[,，]\s*/i, 'help ');
}

export function isHelpEscalationIntent(text) {
  const normalized = String(text ?? '').trim();
  if (!normalized) return false;
  const commandText = normalizeHelpEscalationCommandText(normalized);
  for (const candidate of [normalized, commandText]) {
    if (!candidate) continue;
    if (HELP_INTENT_PATTERNS.some((pattern) => pattern.test(candidate))) {
      return true;
    }
  }
  return false;
}

export function extractHelpEscalationProblemText(text) {
  const commandText = normalizeHelpEscalationCommandText(text);
  if (!commandText) return '';
  for (const pattern of HELP_COMMAND_PREFIX_PATTERNS) {
    if (!pattern.test(commandText)) continue;
    return commandText.replace(pattern, '').trim();
  }
  return commandText.trim();
}

export function hasHelpEscalationProblemDescription(text) {
  return extractHelpEscalationProblemText(text).length >= 2;
}

const HELP_PAGE_PATH_PATTERN = /\b(public\/[^\s"'<>]+\.html)\b/i;

export function extractHelpEscalationPagePath(userText, context = {}) {
  const rawContextPath = context.relativePath ?? context.pagePath ?? context.workspaceRelativePath ?? '';
  const fromContext = normalizeDeliveryRelativePath(rawContextPath);
  if (fromContext) return fromContext;
  const text = String(userText ?? '');
  const match = text.match(HELP_PAGE_PATH_PATTERN);
  return match?.[1] ? match[1].replace(/\\/g, '/').trim() : null;
}

export function extractHelpEscalationSessionId(escalation) {
  const context = escalation?.context ?? {};
  return String(
    context.sessionId
    ?? context.agentSessionId
    ?? escalation?.agentSessionId
    ?? '',
  ).trim() || null;
}

function parseJsonSafe(value, fallback = null) {
  try {
    return JSON.parse(value);
  } catch {
    return fallback;
  }
}

function rowToEscalation(row) {
  if (!row) return null;
  return {
    id: row.id,
    userId: row.user_id,
    channel: row.channel,
    status: row.status,
    userText: row.user_text,
    context: parseJsonSafe(row.context_json, {}),
    agentSessionId: row.agent_session_id,
    resultText: row.result_text,
    agentOutput: row.agent_output,
    errorMessage: row.error_message,
    createdAt: Number(row.created_at),
    updatedAt: Number(row.updated_at),
    startedAt: row.started_at == null ? null : Number(row.started_at),
    completedAt: row.completed_at == null ? null : Number(row.completed_at),
  };
}

export function buildHelpEscalationPrompt(escalation, { memindRoot = process.cwd() } = {}) {
  const context = escalation?.context ?? {};
  const sessionId = context.sessionId ?? context.agentSessionId ?? escalation.agentSessionId ?? null;
  return [
    '你是 Memind 平台值班工程师。用户通过 help 指令请求人工介入，请在本机直接排查并修复问题。',
    '',
    '要求：',
    '1. 工作目录是 Memind 仓库，可以直接修改文件、运行脚本、重启相关服务。',
    '2. 优先修复用户问题，不要只做分析。',
    '3. 页面/链接类问题：必须先修复 delivery contract，再通过 Goose 原会话把链接补发给用户（禁止只改库不通知）。',
    '4. 页面链接补救优先运行（把参数换成工单上下文中的真实值）：',
    '   node scripts/help-remediate-page-delivery.mjs \\',
    '     --user-id=<用户ID> \\',
    '     --session-id=<会话ID> \\',
    '     --page=public/<页面文件名>.html \\',
    '     --via-goose',
    '5. 若用户描述不清，可在 userMessage 里继续引导其补充；问题已解决则明确告知链接与下一步。',
    '6. 完成后用中文给出简短结果，说明做了什么、用户接下来怎么用。',
    '7. 最后一行单独输出 JSON：{"status":"succeeded|failed","userMessage":"给用户的中文回复"}',
    '',
    `Memind 根目录: ${memindRoot}`,
    `工单 ID: ${escalation.id}`,
    `用户 ID: ${escalation.userId}`,
    `渠道: ${escalation.channel}`,
    `用户原文: ${escalation.userText}`,
    `会话 ID: ${sessionId ?? '无'}`,
    `OpenID: ${context.openid ?? '无'}`,
    `Request ID: ${context.requestId ?? '无'}`,
    '',
    '相关上下文 JSON:',
    JSON.stringify(context, null, 2),
  ].join('\n');
}

export function parseHelpEscalationAgentResult(stdout) {
  const text = String(stdout ?? '').trim();
  if (!text) {
    return {
      status: HELP_ESCALATION_STATUS.FAILED,
      userMessage: '工程师处理失败：Cursor 未返回结果。',
      rawOutput: text,
    };
  }

  const lines = text.split('\n').map((line) => line.trim()).filter(Boolean);
  for (let index = lines.length - 1; index >= 0; index -= 1) {
    const candidate = parseJsonSafe(lines[index], null);
    if (
      candidate
      && typeof candidate === 'object'
      && typeof candidate.userMessage === 'string'
      && candidate.userMessage.trim()
    ) {
      const status = String(candidate.status ?? '').trim().toLowerCase() === 'failed'
        ? HELP_ESCALATION_STATUS.FAILED
        : HELP_ESCALATION_STATUS.SUCCEEDED;
      return {
        status,
        userMessage: candidate.userMessage.trim(),
        rawOutput: text,
      };
    }
  }

  return {
    status: HELP_ESCALATION_STATUS.SUCCEEDED,
    userMessage: text.slice(-4000),
    rawOutput: text,
  };
}

export function resolveCursorHelpAgentBin(env = process.env) {
  return resolveSharedCursorAgentBin(env);
}

export function resolveCursorHelpWorkspace(env = process.env, fallbackRoot = process.cwd()) {
  return expandHome(env.MEMIND_CURSOR_HELP_WORKSPACE ?? fallbackRoot);
}

export function runCursorHelpAgent({
  prompt,
  workspace,
  agentBin = resolveCursorHelpAgentBin(),
  env = process.env,
  logger = console,
  timeoutMs = Number(env.MEMIND_CURSOR_HELP_TIMEOUT_MS ?? 30 * 60 * 1000),
}) {
  const args = [
    '--print',
    '--trust',
    '--force',
    '--approve-mcps',
    '--output-format',
    'text',
    '--workspace',
    workspace,
    prompt,
  ];

  logger.info?.('[cursor-help] spawning agent', {
    agentBin,
    workspace,
    timeoutMs,
  });

  return new Promise((resolve, reject) => {
    const child = spawn(agentBin, args, {
      cwd: workspace,
      env: { ...env },
      stdio: ['ignore', 'pipe', 'pipe'],
    });

    let stdout = '';
    let stderr = '';
    const timer = setTimeout(() => {
      child.kill('SIGTERM');
      reject(new Error(`Cursor help agent timed out after ${timeoutMs}ms`));
    }, timeoutMs);
    timer.unref?.();

    child.stdout.on('data', (chunk) => {
      stdout += String(chunk);
    });
    child.stderr.on('data', (chunk) => {
      stderr += String(chunk);
    });
    child.on('error', (error) => {
      clearTimeout(timer);
      reject(error);
    });
    child.on('close', (code) => {
      clearTimeout(timer);
      if (code !== 0) {
        const error = new Error(
          stderr.trim() || stdout.trim() || `Cursor help agent exited with code ${code}`,
        );
        error.code = code;
        error.stdout = stdout;
        error.stderr = stderr;
        reject(error);
        return;
      }
      resolve({ stdout, stderr });
    });
  });
}

export function createHelpEscalationService({
  pool,
  logger = console,
  env = process.env,
} = {}) {
  const enabled = envFlag(env.MEMIND_CURSOR_HELP_ENABLED, false);
  const memindRoot = resolveCursorHelpWorkspace(env);

  async function enqueue({
    userId,
    channel,
    userText,
    context = {},
    agentSessionId = null,
  }) {
    if (!enabled) {
      throw new Error('Cursor help escalation is disabled');
    }
    const id = crypto.randomUUID();
    const now = nowMs();
    await pool.query(
      `INSERT INTO h5_help_escalations (
         id, user_id, channel, status, user_text, context_json, agent_session_id,
         created_at, updated_at
       ) VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?)`,
      [
        id,
        userId,
        channel,
        HELP_ESCALATION_STATUS.QUEUED,
        userText,
        JSON.stringify(context ?? {}),
        agentSessionId,
        now,
        now,
      ],
    );
    return getById(id);
  }

  async function getById(id) {
    const [rows] = await pool.query(
      'SELECT * FROM h5_help_escalations WHERE id = ? LIMIT 1',
      [id],
    );
    return rowToEscalation(rows[0]);
  }

  async function claimNext(workerId = 'cursor-help-worker') {
    const connection = await pool.getConnection();
    try {
      await connection.beginTransaction();
      const [rows] = await connection.query(
        `SELECT *
         FROM h5_help_escalations
         WHERE status = ?
         ORDER BY created_at ASC
         LIMIT 1
         FOR UPDATE`,
        [HELP_ESCALATION_STATUS.QUEUED],
      );
      const row = rows[0];
      if (!row) {
        await connection.commit();
        return null;
      }
      const now = nowMs();
      await connection.query(
        `UPDATE h5_help_escalations
         SET status = ?, started_at = ?, updated_at = ?, error_message = NULL
         WHERE id = ?`,
        [HELP_ESCALATION_STATUS.RUNNING, now, now, row.id],
      );
      await connection.commit();
      logger.info?.('[cursor-help] claimed escalation', { id: row.id, workerId });
      return rowToEscalation({ ...row, status: HELP_ESCALATION_STATUS.RUNNING, started_at: now, updated_at: now });
    } catch (error) {
      await connection.rollback();
      throw error;
    } finally {
      connection.release();
    }
  }

  async function complete(id, {
    status,
    resultText = null,
    agentOutput = null,
    errorMessage = null,
  }) {
    const now = nowMs();
    await pool.query(
      `UPDATE h5_help_escalations
       SET status = ?, result_text = ?, agent_output = ?, error_message = ?,
           completed_at = ?, updated_at = ?
       WHERE id = ?`,
      [status, resultText, agentOutput, errorMessage, now, now, id],
    );
    return getById(id);
  }

  async function getQueueStats() {
    const [rows] = await pool.query(
      `SELECT status, COUNT(*) AS count
       FROM h5_help_escalations
       GROUP BY status`,
    );
    const stats = {
      queued: 0,
      running: 0,
      succeeded: 0,
      failed: 0,
    };
    for (const row of rows) {
      stats[row.status] = Number(row.count);
    }
    return stats;
  }

  return {
    enabled,
    memindRoot,
    enqueue,
    getById,
    claimNext,
    complete,
    getQueueStats,
    buildPrompt: (escalation) => buildHelpEscalationPrompt(escalation, { memindRoot }),
  };
}

export async function tryHandleHelpEscalation({
  helpEscalationService,
  userId,
  channel,
  userText,
  context = {},
  agentSessionId = null,
  onAck = null,
}) {
  if (!helpEscalationService?.enabled) return null;
  const rawText = String(userText ?? '').trim();
  const commandText = normalizeHelpEscalationCommandText(rawText);
  if (!isHelpEscalationIntent(commandText || rawText)) return null;

  if (!hasHelpEscalationProblemDescription(commandText || rawText)) {
    const message = HELP_ESCALATION_DETAILS_PROMPT;
    if (typeof onAck === 'function') {
      await onAck(message, null);
    }
    return { needsDetails: true, message };
  }

  const escalation = await helpEscalationService.enqueue({
    userId,
    channel,
    userText: commandText || rawText,
    context,
    agentSessionId,
  });
  if (typeof onAck === 'function') {
    await onAck(HELP_ESCALATION_ACK_TEXT, escalation);
  }
  return escalation;
}

export async function deliverHelpEscalationResult({
  escalation,
  scheduleService = null,
  sendWechatTextToUser = null,
  logger = console,
}) {
  const userMessage = String(
    escalation?.resultText
      ?? escalation?.errorMessage
      ?? '工程师已处理完成，但未返回详细说明。',
  ).trim();
  const title = escalation?.status === HELP_ESCALATION_STATUS.SUCCEEDED
    ? '工程师已处理完成'
    : '工程师处理失败';

  if (scheduleService?.createUserNotification) {
    await scheduleService.createUserNotification({
      userId: escalation.userId,
      channel: 'web',
      notificationType: 'help_escalation_result',
      title,
      body: userMessage,
      data: {
        escalationId: escalation.id,
        status: escalation.status,
        channel: escalation.channel,
      },
    }).catch((error) => {
      logger.warn?.('[cursor-help] web notification failed:', error);
    });
  }

  let wechatSent = false;
  if (typeof sendWechatTextToUser === 'function') {
    wechatSent = await sendWechatTextToUser(
      escalation.userId,
      `${title}\n${userMessage}`.trim(),
    ).catch((error) => {
      logger.warn?.('[cursor-help] wechat notification failed:', error);
      return false;
    });
  }

  return { userMessage, wechatSent };
}