import { computed, onMounted, ref } from 'vue'

import { useSystemState } from '../../composables/useSystemState.js'
import { fetchSettings, saveSettings, testModelConnectivity } from '../../services/settings.js'
import { useToast } from '../../composables/useToast.js'

const SETTINGS_STORAGE_KEY = 'x-financial-settings-draft'
const CURRENT_YEAR = new Date().getFullYear()
const CUSTOM_OPENAI_PROVIDER = 'Custom OpenAI Compatible'
const MODEL_SECRET_MASK = '********'

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、系统显示名称和版权信息，保存后会同步更新当前系统品牌展示。',
    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: '集中管理管理员账号、邮箱和登录安全策略。密码仅在当前输入时可见，不会写入浏览器草稿。',
    actionLabel: '保存安全设置'
  },
  {
    id: 'llm',
    label: '大语言模型',
    title: '模型接入配置',
    desc: '主模型、备份模型与多模态模型',
    longDesc: '集中维护主模型、备份模型、VLM 模型和 Embedding 模型的接入参数，供 AI 助手和识别链路调用。',
    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，保证问题排查和合规审计可追溯。',
    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、告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']

const PROVIDER_OPTIONS = [
  'MiniMax',
  'GLM',
  'Kimi',
  'Ali',
  'Codex',
  'Claude',
  'Gemini',
  CUSTOM_OPENAI_PROVIDER
]

const PROVIDER_ENDPOINTS = {
  MiniMax: 'https://api.minimaxi.com/v1',
  GLM: 'https://open.bigmodel.cn/api/paas/v4/',
  Kimi: 'https://api.moonshot.ai/v1',
  Ali: 'https://dashscope.aliyuncs.com/compatible-mode/v1',
  Codex: 'https://api.openai.com/v1',
  Claude: 'https://api.anthropic.com/v1/',
  Gemini: 'https://generativelanguage.googleapis.com/v1beta/openai/',
  [CUSTOM_OPENAI_PROVIDER]: ''
}

const LEGACY_PROVIDER_MAP = {
  'OpenAI Compatible': 'Codex',
  'Azure OpenAI': CUSTOM_OPENAI_PROVIDER,
  Ollama: CUSTOM_OPENAI_PROVIDER,
  '自定义网关': CUSTOM_OPENAI_PROVIDER
}

const MODEL_TEST_CONFIGS = {
  main: {
    label: '主模型',
    providerKey: 'mainProvider',
    modelKey: 'mainModel',
    endpointKey: 'mainEndpoint',
    apiKeyKey: 'mainApiKey',
    capability: 'chat'
  },
  backup: {
    label: '备份模型',
    providerKey: 'backupProvider',
    modelKey: 'backupModel',
    endpointKey: 'backupEndpoint',
    apiKeyKey: 'backupApiKey',
    capability: 'chat'
  },
  vlm: {
    label: 'VLM 模型',
    providerKey: 'vlmProvider',
    modelKey: 'vlmModel',
    endpointKey: 'vlmEndpoint',
    apiKeyKey: 'vlmApiKey',
    capability: 'chat'
  },
  embedding: {
    label: 'Embedding 模型',
    providerKey: 'embeddingProvider',
    modelKey: 'embeddingModel',
    endpointKey: 'embeddingEndpoint',
    apiKeyKey: 'embeddingApiKey',
    capability: 'embedding'
  }
}

const MODEL_API_KEY_CONFIGS = Object.values(MODEL_TEST_CONFIGS)

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

function normalizeProviderValue(value, fallback = 'Codex') {
  const normalized = normalizeValue(value)

  if (PROVIDER_OPTIONS.includes(normalized)) {
    return normalized
  }

  if (LEGACY_PROVIDER_MAP[normalized]) {
    return LEGACY_PROVIDER_MAP[normalized]
  }

  return fallback
}

function getProviderEndpoint(provider) {
  return PROVIDER_ENDPOINTS[provider] ?? ''
}

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: '',
      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,
      adminPasswordConfigured: false
    },
    llmForm: {
      mainProvider: 'Codex',
      mainModel: 'codex-mini-latest',
      mainEndpoint: getProviderEndpoint('Codex'),
      mainApiKey: '',
      mainApiKeyConfigured: false,
      backupProvider: 'GLM',
      backupModel: 'glm-5.1',
      backupEndpoint: getProviderEndpoint('GLM'),
      backupApiKey: '',
      backupApiKeyConfigured: false,
      vlmProvider: 'Gemini',
      vlmModel: 'gemini-2.5-flash',
      vlmEndpoint: getProviderEndpoint('Gemini'),
      vlmApiKey: '',
      vlmApiKeyConfigured: false,
      embeddingProvider: 'GLM',
      embeddingModel: 'Embedding-3',
      embeddingEndpoint: getProviderEndpoint('GLM'),
      embeddingApiKey: '',
      embeddingApiKeyConfigured: false
    },
    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: '',
      passwordConfigured: false,
      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 mergeState(baseState, overrideState) {
  const mergedLlmForm = { ...baseState.llmForm, ...(overrideState?.llmForm || {}) }

  mergedLlmForm.mainProvider = normalizeProviderValue(mergedLlmForm.mainProvider, baseState.llmForm.mainProvider)
  mergedLlmForm.backupProvider = normalizeProviderValue(mergedLlmForm.backupProvider, baseState.llmForm.backupProvider)
  mergedLlmForm.vlmProvider = normalizeProviderValue(mergedLlmForm.vlmProvider, baseState.llmForm.vlmProvider)
  mergedLlmForm.embeddingProvider = normalizeProviderValue(
    mergedLlmForm.embeddingProvider,
    baseState.llmForm.embeddingProvider
  )

  return {
    companyForm: { ...baseState.companyForm, ...(overrideState?.companyForm || {}) },
    adminForm: { ...baseState.adminForm, ...(overrideState?.adminForm || {}) },
    llmForm: mergedLlmForm,
    logForm: { ...baseState.logForm, ...(overrideState?.logForm || {}) },
    mailForm: { ...baseState.mailForm, ...(overrideState?.mailForm || {}) }
  }
}

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

function getModelConfiguredKey(apiKeyKey) {
  return `${apiKeyKey}Configured`
}

function isModelSecretMask(value) {
  return value === MODEL_SECRET_MASK
}

function maskConfiguredModelSecrets(state) {
  for (const config of MODEL_API_KEY_CONFIGS) {
    const configuredKey = getModelConfiguredKey(config.apiKeyKey)

    if (state.llmForm[configuredKey] && !normalizeValue(state.llmForm[config.apiKeyKey])) {
      state.llmForm[config.apiKeyKey] = MODEL_SECRET_MASK
    }
  }

  return state
}

function buildLlmPayload(llmForm) {
  const payload = { ...llmForm }

  for (const config of MODEL_API_KEY_CONFIGS) {
    if (isModelSecretMask(payload[config.apiKeyKey])) {
      payload[config.apiKeyKey] = ''
    }
  }

  return payload
}

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

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

function isModelConfigReady(provider, model, endpoint) {
  return Boolean(normalizeValue(provider) && normalizeValue(model) && normalizeValue(endpoint))
}

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(
      isModelConfigReady(state.llmForm.mainProvider, state.llmForm.mainModel, state.llmForm.mainEndpoint) &&
        isModelConfigReady(state.llmForm.backupProvider, state.llmForm.backupModel, state.llmForm.backupEndpoint) &&
        isModelConfigReady(state.llmForm.vlmProvider, state.llmForm.vlmModel, state.llmForm.vlmEndpoint) &&
        isModelConfigReady(
          state.llmForm.embeddingProvider,
          state.llmForm.embeddingModel,
          state.llmForm.embeddingEndpoint
        )
    ),
    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 buildResolvedDefaults = () => buildDefaultState(companyProfile.value, currentUser.value)
    const pageState = ref(mergeState(buildResolvedDefaults(), readStoredSettings()))
    const activeSection = ref('profile')
    const modelTestState = ref({
      main: { status: 'idle', message: '' },
      backup: { status: 'idle', message: '' },
      vlm: { status: 'idle', message: '' },
      embedding: { status: 'idle', message: '' }
    })

    const sections = SECTION_DEFINITIONS
    const logLevels = LOG_LEVELS
    const providerOptions = PROVIDER_OPTIONS

    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 updateBrandPreviewFromState(state) {
      updateCompanyProfilePreview({
        name: normalizeValue(state.companyForm.displayName),
        code: normalizeValue(state.companyForm.companyCode),
        adminEmail: normalizeValue(state.adminForm.adminEmail)
      })
    }

    function applyLoadedSnapshot(snapshot, options = {}) {
      const {
        mergeDraft = false,
        preserveModelApiKeys = false,
        preserveAdminPasswords = false,
        preserveMailPassword = false
      } = options

      const currentState = pageState.value
      let nextState = mergeState(buildResolvedDefaults(), snapshot)

      if (mergeDraft) {
        nextState = mergeState(nextState, readStoredSettings())
      }

      if (preserveModelApiKeys) {
        nextState.llmForm.mainApiKey = currentState.llmForm.mainApiKey
        nextState.llmForm.backupApiKey = currentState.llmForm.backupApiKey
        nextState.llmForm.vlmApiKey = currentState.llmForm.vlmApiKey
        nextState.llmForm.embeddingApiKey = currentState.llmForm.embeddingApiKey
      }

      if (preserveAdminPasswords) {
        nextState.adminForm.newPassword = currentState.adminForm.newPassword
        nextState.adminForm.confirmPassword = currentState.adminForm.confirmPassword
      }

      if (preserveMailPassword) {
        nextState.mailForm.password = currentState.mailForm.password
      }

      pageState.value = maskConfiguredModelSecrets(nextState)
      persistSettings(pageState.value)
      updateBrandPreviewFromState(pageState.value)
    }

    async function loadSettingsSnapshot() {
      try {
        const snapshot = await fetchSettings()
        applyLoadedSnapshot(snapshot, { mergeDraft: true })
      } catch (error) {
        persistSettings(pageState.value)
        updateBrandPreviewFromState(pageState.value)
        toast(error.message || '无法加载已保存设置，继续使用当前会话草稿。')
      }
    }

    function buildSettingsPayload() {
      return {
        companyForm: { ...pageState.value.companyForm },
        adminForm: { ...pageState.value.adminForm },
        llmForm: buildLlmPayload(pageState.value.llmForm),
        logForm: { ...pageState.value.logForm },
        mailForm: { ...pageState.value.mailForm }
      }
    }

    async function persistRemoteSettings(successMessage, options = {}) {
      try {
        const snapshot = await saveSettings(buildSettingsPayload())
        applyLoadedSnapshot(snapshot, options)
        toast(successMessage)
        return true
      } catch (error) {
        toast(error.message || '设置保存失败，请稍后重试。')
        return false
      }
    }

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

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

    function applyProviderPreset(testKey) {
      const config = MODEL_TEST_CONFIGS[testKey]
      const llmForm = pageState.value.llmForm
      const provider = normalizeProviderValue(llmForm[config.providerKey], CUSTOM_OPENAI_PROVIDER)

      llmForm[config.providerKey] = provider
      llmForm[config.endpointKey] = getProviderEndpoint(provider)
    }

    function getModelTestState(testKey) {
      return modelTestState.value[testKey] || { status: 'idle', message: '' }
    }

    function isModelTesting(testKey) {
      return getModelTestState(testKey).status === 'testing'
    }

    function buildModelTestPayload(testKey) {
      const config = MODEL_TEST_CONFIGS[testKey]
      const llmForm = pageState.value.llmForm
      const apiKey = llmForm[config.apiKeyKey]

      return {
        provider: llmForm[config.providerKey],
        model: llmForm[config.modelKey],
        endpoint: llmForm[config.endpointKey],
        api_key: isModelSecretMask(apiKey) ? '' : apiKey,
        capability: config.capability,
        slot: testKey
      }
    }

    function clearModelSecretMask(testKey) {
      const config = MODEL_TEST_CONFIGS[testKey]

      if (isModelSecretMask(pageState.value.llmForm[config.apiKeyKey])) {
        pageState.value.llmForm[config.apiKeyKey] = ''
      }
    }

    async function testModelConnection(testKey) {
      const config = MODEL_TEST_CONFIGS[testKey]
      const payload = buildModelTestPayload(testKey)

      if (!isModelConfigReady(payload.provider, payload.model, payload.endpoint)) {
        const message = `请先完整填写${config.label}的供应商、模型名称和接口地址。`
        modelTestState.value[testKey] = { status: 'error', message }
        toast(message)
        return
      }

      modelTestState.value[testKey] = { status: 'testing', message: '正在测试模型连通性...' }

      try {
        const result = await testModelConnectivity(payload)

        modelTestState.value[testKey] = {
          status: result.ok ? 'success' : 'error',
          message: result.detail || (result.ok ? '模型连接成功。' : '模型连接失败。')
        }

        toast(modelTestState.value[testKey].message)
      } catch (error) {
        const message = error.message || '模型测试请求失败，请确认 FastAPI 已启动。'
        modelTestState.value[testKey] = { status: 'error', message }
        toast(message)
      }
    }

    async 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
      }

      pageState.value.mailForm.senderName = normalizeValue(companyForm.displayName)
      await persistRemoteSettings('企业信息已保存并应用到当前系统。', {
        preserveModelApiKeys: true,
        preserveAdminPasswords: true,
        preserveMailPassword: true
      })
    }

    async 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
        }
      }

      await persistRemoteSettings('管理员安全设置已保存。', {
        preserveModelApiKeys: true,
        preserveAdminPasswords: false,
        preserveMailPassword: true
      })
    }

    async function saveLlmSection() {
      const llmForm = pageState.value.llmForm
      const modelConfigs = [
        ['主模型', llmForm.mainProvider, llmForm.mainModel, llmForm.mainEndpoint],
        ['备份模型', llmForm.backupProvider, llmForm.backupModel, llmForm.backupEndpoint],
        ['VLM 模型', llmForm.vlmProvider, llmForm.vlmModel, llmForm.vlmEndpoint],
        ['Embedding 模型', llmForm.embeddingProvider, llmForm.embeddingModel, llmForm.embeddingEndpoint]
      ]

      for (const [label, provider, model, endpoint] of modelConfigs) {
        if (!isModelConfigReady(provider, model, endpoint)) {
          toast(`请完整填写${label}的供应商、模型名称和接口地址。`)
          return
        }
      }

      await persistRemoteSettings('模型配置已保存。', {
        preserveModelApiKeys: true,
        preserveAdminPasswords: true,
        preserveMailPassword: true
      })
    }

    async 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
      }

      await persistRemoteSettings('日志策略已保存。', {
        preserveModelApiKeys: true,
        preserveAdminPasswords: true,
        preserveMailPassword: true
      })
    }

    async 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
      }

      await persistRemoteSettings('邮箱配置已保存。', {
        preserveModelApiKeys: true,
        preserveAdminPasswords: true,
        preserveMailPassword: false
      })
    }

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

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

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

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

      await saveMailSection()
    }

    onMounted(() => {
      loadSettingsSnapshot()
    })

    return {
      activeSection,
      activeSectionConfig,
      activateSection,
      applyProviderPreset,
      clearModelSecretMask,
      completedSectionCount,
      getModelTestState,
      isModelTesting,
      logLevels,
      modelTestState,
      pageState,
      providerOptions,
      saveActiveSection,
      sectionStatus,
      sections,
      testModelConnection,
      toggleBoolean
    }
  }
}