import { computed, ref } from 'vue'

import { useSystemState } from '../../composables/useSystemState.js'
import { useToast } from '../../composables/useToast.js'

const SETTINGS_STORAGE_KEY = 'x-financial-settings-draft'
const CURRENT_YEAR = new Date().getFullYear()

const SECTION_DEFINITIONS = [
  {
    id: 'profile',
    label: '企业信息',
    title: '系统基本信息',
    desc: '公司名称、品牌与版权',
    longDesc: '统一维护企业名称、系统显示名和版权信息，保存后会直接同步到当前界面的品牌预览。',
    actionLabel: '保存企业信息'
  },
  {
    id: 'admin',
    label: '管理员安全',
    title: '管理员账号与安全策略',
    desc: '账号、密码与登录安全',
    longDesc: '管理最高权限管理员的账号、密码和登录安全策略，密码类字段仅用于本次填写，不会进入浏览器草稿。',
    actionLabel: '保存安全设置'
  },
  {
    id: 'llm',
    label: '大语言模型',
    title: '模型接入配置',
    desc: '供应商、模型与推理策略',
    longDesc: '配置 AI 助手与识别流程依赖的大模型接入信息，并维护推理模式、知识检索和输出行为。',
    actionLabel: '保存模型配置'
  },
  {
    id: 'logs',
    label: '日志策略',
    title: '日志与审计策略',
    desc: '日志级别、留存与脱敏',
    longDesc: '定义系统日志级别、留存周期和审计策略，保证后续排障、追溯和安全审计有完整依据。',
    actionLabel: '保存日志策略'
  },
  {
    id: 'mail',
    label: '邮箱设置',
    title: '邮箱通知配置',
    desc: 'SMTP 与通知投递策略',
    longDesc: '维护系统邮件发送配置和通知投递策略，审批、预警和摘要邮件都会依赖这里的设置。',
    actionLabel: '保存邮箱配置'
  }
]

const LOG_LEVELS = ['DEBUG', 'INFO', 'WARN', 'ERROR']

function normalizeValue(value) {
  return String(value ?? '').trim()
}

function buildDefaultState(companyProfile, currentUser) {
  const companyName = normalizeValue(companyProfile?.name) || 'X-Financial'
  const companyCode = normalizeValue(companyProfile?.code) || 'XF-001'
  const adminEmail =
    normalizeValue(companyProfile?.adminEmail) ||
    normalizeValue(currentUser?.email) ||
    'admin@example.com'
  const adminAccount = normalizeValue(currentUser?.username) || 'superadmin'

  return {
    companyForm: {
      companyName,
      displayName: companyName,
      companyCode,
      recordNumber: '',
      environment: '生产环境',
      copyright: `Copyright © 2024-${CURRENT_YEAR} ${companyName}. All Rights Reserved.`
    },
    adminForm: {
      adminAccount,
      adminEmail,
      newPassword: '',
      confirmPassword: '',
      sessionTimeout: Number(import.meta.env.VITE_AUTH_IDLE_TIMEOUT_MINUTES || 30),
      noticeEmail: adminEmail,
      mfaEnabled: true,
      strongPassword: true,
      loginAlertEnabled: true
    },
    llmForm: {
      provider: 'OpenAI Compatible',
      model: 'gpt-4.1-mini',
      endpoint: 'https://api.openai.com/v1',
      embeddingModel: 'text-embedding-3-large',
      apiKey: '',
      reasoningMode: 'balanced',
      maxTokens: 4096,
      temperature: 0.2,
      knowledgeEnabled: true,
      citationEnabled: true
    },
    logForm: {
      level: 'INFO',
      retentionDays: 180,
      archiveCycle: 'weekly',
      logPath: 'server/logs/app.log',
      alertEmail: adminEmail,
      operationAudit: true,
      loginAudit: true,
      maskSensitive: true
    },
    mailForm: {
      smtpHost: 'smtp.exmail.qq.com',
      port: 465,
      encryption: 'SSL/TLS',
      senderName: companyName,
      senderAddress: adminEmail,
      username: adminEmail,
      password: '',
      alertEnabled: true,
      digestEnabled: false,
      digestTime: '09:00',
      defaultReceiver: adminEmail
    }
  }
}

function readStoredSettings() {
  if (typeof window === 'undefined') {
    return null
  }

  const raw = window.sessionStorage.getItem(SETTINGS_STORAGE_KEY)
  if (!raw) {
    return null
  }

  try {
    return JSON.parse(raw)
  } catch {
    return null
  }
}

function mergeStoredState(defaults, stored) {
  return {
    companyForm: { ...defaults.companyForm, ...(stored?.companyForm || {}) },
    adminForm: { ...defaults.adminForm, ...(stored?.adminForm || {}) },
    llmForm: { ...defaults.llmForm, ...(stored?.llmForm || {}) },
    logForm: { ...defaults.logForm, ...(stored?.logForm || {}) },
    mailForm: { ...defaults.mailForm, ...(stored?.mailForm || {}) }
  }
}

function sanitizeForStorage(state) {
  return {
    companyForm: { ...state.companyForm },
    adminForm: {
      ...state.adminForm,
      newPassword: '',
      confirmPassword: ''
    },
    llmForm: {
      ...state.llmForm,
      apiKey: ''
    },
    logForm: { ...state.logForm },
    mailForm: {
      ...state.mailForm,
      password: ''
    }
  }
}

function persistSettings(state) {
  if (typeof window === 'undefined') {
    return
  }

  window.sessionStorage.setItem(SETTINGS_STORAGE_KEY, JSON.stringify(sanitizeForStorage(state)))
}

function computeSectionStatus(state) {
  return {
    profile: Boolean(
      normalizeValue(state.companyForm.companyName) &&
        normalizeValue(state.companyForm.displayName) &&
        normalizeValue(state.companyForm.copyright)
    ),
    admin: Boolean(
      normalizeValue(state.adminForm.adminAccount) &&
        normalizeValue(state.adminForm.adminEmail) &&
        Number(state.adminForm.sessionTimeout) >= 5
    ),
    llm: Boolean(
      normalizeValue(state.llmForm.provider) &&
        normalizeValue(state.llmForm.model) &&
        normalizeValue(state.llmForm.endpoint)
    ),
    logs: Boolean(
      normalizeValue(state.logForm.level) &&
        Number(state.logForm.retentionDays) > 0 &&
        normalizeValue(state.logForm.logPath)
    ),
    mail: Boolean(
      normalizeValue(state.mailForm.smtpHost) &&
        Number(state.mailForm.port) > 0 &&
        normalizeValue(state.mailForm.senderAddress) &&
        normalizeValue(state.mailForm.username)
    )
  }
}

export default {
  name: 'SettingsView',
  setup() {
    const { toast } = useToast()
    const { companyProfile, currentUser, updateCompanyProfilePreview } = useSystemState()

    const defaults = buildDefaultState(companyProfile.value, currentUser.value)
    const pageState = ref(mergeStoredState(defaults, readStoredSettings()))
    const activeSection = ref('profile')

    const sections = SECTION_DEFINITIONS
    const logLevels = LOG_LEVELS

    const sectionStatus = computed(() => computeSectionStatus(pageState.value))
    const completedSectionCount = computed(() => Object.values(sectionStatus.value).filter(Boolean).length)
    const activeSectionConfig = computed(
      () => sections.find((section) => section.id === activeSection.value) || sections[0]
    )

    function activateSection(sectionId) {
      activeSection.value = sectionId
    }

    function toggleBoolean(formKey, field) {
      pageState.value[formKey][field] = !pageState.value[formKey][field]
    }

    function saveProfileSection() {
      const companyForm = pageState.value.companyForm

      if (!normalizeValue(companyForm.companyName)) {
        toast('请输入企业名称。')
        return
      }

      if (!normalizeValue(companyForm.displayName)) {
        toast('请输入系统显示名称。')
        return
      }

      if (!normalizeValue(companyForm.copyright)) {
        toast('请输入版权信息。')
        return
      }

      updateCompanyProfilePreview({
        name: normalizeValue(companyForm.displayName),
        code: normalizeValue(companyForm.companyCode)
      })

      pageState.value.mailForm.senderName = normalizeValue(companyForm.displayName)
      persistSettings(pageState.value)
      toast('企业信息已保存并应用到当前界面预览。')
    }

    function saveAdminSection() {
      const adminForm = pageState.value.adminForm

      if (!normalizeValue(adminForm.adminAccount)) {
        toast('请输入管理员账号。')
        return
      }

      if (!normalizeValue(adminForm.adminEmail)) {
        toast('请输入管理员邮箱。')
        return
      }

      if (Number(adminForm.sessionTimeout) < 5) {
        toast('会话超时时间不能少于 5 分钟。')
        return
      }

      if (adminForm.newPassword) {
        if (adminForm.newPassword.length < 5) {
          toast('管理员密码至少需要 5 位。')
          return
        }

        if (adminForm.newPassword !== adminForm.confirmPassword) {
          toast('两次输入的管理员密码不一致。')
          return
        }
      }

      updateCompanyProfilePreview({
        adminEmail: normalizeValue(adminForm.adminEmail)
      })

      persistSettings(pageState.value)
      adminForm.newPassword = ''
      adminForm.confirmPassword = ''
      toast('管理员安全设置已保存。')
    }

    function saveLlmSection() {
      const llmForm = pageState.value.llmForm

      if (
        !normalizeValue(llmForm.provider) ||
        !normalizeValue(llmForm.model) ||
        !normalizeValue(llmForm.endpoint)
      ) {
        toast('请完整填写模型供应商、模型名称和接口地址。')
        return
      }

      persistSettings(pageState.value)
      llmForm.apiKey = ''
      toast('模型配置已保存。')
    }

    function saveLogsSection() {
      const logForm = pageState.value.logForm

      if (!normalizeValue(logForm.level) || Number(logForm.retentionDays) <= 0) {
        toast('请填写有效的日志级别和留存天数。')
        return
      }

      if (!normalizeValue(logForm.logPath)) {
        toast('请输入日志路径。')
        return
      }

      persistSettings(pageState.value)
      toast('日志策略已保存。')
    }

    function saveMailSection() {
      const mailForm = pageState.value.mailForm

      if (!normalizeValue(mailForm.smtpHost) || Number(mailForm.port) <= 0) {
        toast('请填写有效的 SMTP Host 和端口。')
        return
      }

      if (!normalizeValue(mailForm.senderAddress) || !normalizeValue(mailForm.username)) {
        toast('请填写发件人邮箱和 SMTP 登录账号。')
        return
      }

      persistSettings(pageState.value)
      mailForm.password = ''
      toast('邮箱配置已保存。')
    }

    function saveActiveSection() {
      if (activeSection.value === 'profile') {
        saveProfileSection()
        return
      }

      if (activeSection.value === 'admin') {
        saveAdminSection()
        return
      }

      if (activeSection.value === 'llm') {
        saveLlmSection()
        return
      }

      if (activeSection.value === 'logs') {
        saveLogsSection()
        return
      }

      saveMailSection()
    }

    return {
      activeSection,
      activeSectionConfig,
      activateSection,
      completedSectionCount,
      logLevels,
      pageState,
      saveActiveSection,
      sectionStatus,
      sections,
      toggleBoolean
    }
  }
}