var db = require('../common/db')
var RESPONSE = require('../common/response').RESPONSE
var ERROR_CODES = require('../common/response').ERROR_CODES

exports.main_handler = async function (event, context) {
  try {
    var token = extractToken(event)
    if (!token) {
      return RESPONSE.error(ERROR_CODES.UNAUTHORIZED.code, ERROR_CODES.UNAUTHORIZED.message)
    }

    var user = await verifyToken(token)
    if (!user) {
      return RESPONSE.error(ERROR_CODES.TOKEN_EXPIRED.code, ERROR_CODES.TOKEN_EXPIRED.message)
    }

    var body = parseBody(event)

    switch (event.path || event.action) {
      case '/record/sync':
        return await syncRecord(user, body)
      case '/record/list':
        return await listRecords(user, body)
      case '/record/detail':
        return await getRecordDetail(user, body)
      default:
        return RESPONSE.error(ERROR_CODES.PARAM_ERROR.code, '未知操作')
    }
  } catch (err) {
    return RESPONSE.error(ERROR_CODES.INTERNAL_ERROR.code, err.message)
  }
}

async function syncRecord(user, body) {
  if (!body.device_id || !body.started_at || !body.ended_at) {
    return RESPONSE.error(ERROR_CODES.PARAM_ERROR.code, '参数不完整')
  }

  var dbConfig = getDbConfig()

  var sessionResult = await db.query(
    'INSERT INTO sessions (user_id, device_id, status, started_at, ended_at, created_at, updated_at) ' +
    'VALUES (?, ?, 2, ?, ?, NOW(), NOW())',
    [user.id, body.device_id, body.started_at, body.ended_at],
    dbConfig
  )

  var sessionId = sessionResult.insertId

  await db.query(
    'INSERT INTO treatment_records ' +
    '(session_id, user_id, device_id, duration_seconds, mode, result_summary, sync_status, synced_at, started_at, ended_at, created_at, updated_at) ' +
    'VALUES (?, ?, ?, ?, ?, ?, 2, NOW(), ?, ?, NOW(), NOW())',
    [
      sessionId,
      user.id,
      body.device_id,
      body.duration_seconds || null,
      body.mode || null,
      body.result_summary || null,
      body.started_at,
      body.ended_at
    ],
    dbConfig
  )

  return RESPONSE.success({ session_id: sessionId })
}

async function listRecords(user, body) {
  var dbConfig = getDbConfig()
  var limit = parseInt(body.limit) || 20
  var offset = parseInt(body.offset) || 0

  var records = await db.query(
    'SELECT * FROM treatment_records WHERE user_id = ? ORDER BY started_at DESC LIMIT ? OFFSET ?',
    [user.id, limit, offset],
    dbConfig
  )

  return RESPONSE.success({ list: records })
}

async function getRecordDetail(user, body) {
  if (!body.record_id) {
    return RESPONSE.error(ERROR_CODES.PARAM_ERROR.code, '缺少记录ID')
  }

  var dbConfig = getDbConfig()

  var records = await db.query(
    'SELECT * FROM treatment_records WHERE id = ? AND user_id = ? LIMIT 1',
    [body.record_id, user.id],
    dbConfig
  )

  if (records.length === 0) {
    return RESPONSE.error(ERROR_CODES.NOT_FOUND.code, ERROR_CODES.NOT_FOUND.message)
  }

  return RESPONSE.success(records[0])
}

function extractToken(event) {
  var header = event.headers || {}
  var auth = header['Authorization'] || header['authorization'] || ''
  if (auth.startsWith('Bearer ')) {
    return auth.substring(7)
  }
  return null
}

async function verifyToken(token) {
  return { id: 1, openid: 'placeholder' }
}

function parseBody(event) {
  if (event.body) {
    try {
      return JSON.parse(event.body)
    } catch (e) {
      return {}
    }
  }
  return event.queryString || {}
}

function getDbConfig() {
  return {
    host: process.env.DB_HOST || 'localhost',
    port: parseInt(process.env.DB_PORT || '3306'),
    user: process.env.DB_USER || 'root',
    password: process.env.DB_PASSWORD || '',
    database: process.env.DB_NAME || 'hox'
  }
}