import { ref } from 'vue'
import { getApiBase } from '@/api/config'

export interface SearchSession {
  id: string
  title: string
  mode: 'keyword' | 'visual' | 'people' | 'agent'
  message_count: number
  created_at: string
  updated_at: string
}

export interface SearchMessage {
  id: string
  session_id: string
  role: 'user' | 'assistant'
  content: string
  results: string
  mode: string
  created_at: string
}

export function useSearchSession() {
  const sessions = ref<SearchSession[]>([])
  const currentSession = ref<SearchSession | null>(null)
  const messages = ref<SearchMessage[]>([])
  const loading = ref(false)
  const error = ref<string | null>(null)

  function getAuthHeaders(): Record<string, string> {
    const stored = localStorage.getItem('mb_admin_token')
    if (stored) {
      try {
        const data = JSON.parse(stored)
        if (new Date(data.expires_at) > new Date()) {
          return { 'Authorization': `Bearer ${data.token}` }
        }
      } catch {}
    }
    return {}
  }

  async function loadSessions() {
    loading.value = true
    error.value = null
    try {
      const base = getApiBase()
      const resp = await fetch(`${base}/api/v2/search-sessions`, {
        headers: getAuthHeaders()
      })
      if (!resp.ok) throw new Error(`HTTP ${resp.status}`)
      const data = await resp.json()
      sessions.value = data.sessions || []
    } catch (e: any) {
      error.value = e.message || 'Failed to load sessions'
    } finally {
      loading.value = false
    }
  }

  async function createSession(title?: string, mode?: string) {
    loading.value = true
    error.value = null
    try {
      const base = getApiBase()
      const resp = await fetch(`${base}/api/v2/search-sessions`, {
        method: 'POST',
        headers: { 'Content-Type': 'application/json', ...getAuthHeaders() },
        body: JSON.stringify({ title: title || '未命名搜尋', mode: mode || 'keyword' })
      })
      if (!resp.ok) throw new Error(`HTTP ${resp.status}`)
      const data = await resp.json()
      await loadSessions()
      return data.session
    } catch (e: any) {
      error.value = e.message || 'Failed to create session'
      return null
    } finally {
      loading.value = false
    }
  }

  async function renameSession(id: string, title: string) {
    loading.value = true
    error.value = null
    try {
      const base = getApiBase()
      const resp = await fetch(`${base}/api/v2/search-sessions/${id}`, {
        method: 'PUT',
        headers: { 'Content-Type': 'application/json', ...getAuthHeaders() },
        body: JSON.stringify({ title })
      })
      if (!resp.ok) throw new Error(`HTTP ${resp.status}`)
      await loadSessions()
      if (currentSession.value?.id === id) {
        currentSession.value.title = title
      }
    } catch (e: any) {
      error.value = e.message || 'Failed to rename session'
    } finally {
      loading.value = false
    }
  }

  async function deleteSession(id: string) {
    loading.value = true
    error.value = null
    try {
      const base = getApiBase()
      const resp = await fetch(`${base}/api/v2/search-sessions/${id}`, {
        method: 'DELETE',
        headers: getAuthHeaders()
      })
      if (!resp.ok) throw new Error(`HTTP ${resp.status}`)
      if (currentSession.value?.id === id) {
        currentSession.value = null
        messages.value = []
      }
      await loadSessions()
    } catch (e: any) {
      error.value = e.message || 'Failed to delete session'
    } finally {
      loading.value = false
    }
  }

  async function loadMessages(sessionId: string) {
    loading.value = true
    error.value = null
    try {
      const base = getApiBase()
      const resp = await fetch(`${base}/api/v2/search-sessions/${sessionId}/messages`, {
        headers: getAuthHeaders()
      })
      if (!resp.ok) throw new Error(`HTTP ${resp.status}`)
      const data = await resp.json()
      messages.value = data.messages || []
    } catch (e: any) {
      error.value = e.message || 'Failed to load messages'
    } finally {
      loading.value = false
    }
  }

  async function saveMessage(sessionId: string, message: { role: string; content: string; mode?: string; results?: any }) {
    loading.value = true
    error.value = null
    try {
      const base = getApiBase()
      const resp = await fetch(`${base}/api/v2/search-sessions/${sessionId}/messages`, {
        method: 'POST',
        headers: { 'Content-Type': 'application/json', ...getAuthHeaders() },
        body: JSON.stringify({
          role: message.role,
          content: message.content,
          mode: message.mode || 'keyword',
          results: message.results ? JSON.stringify(message.results) : ''
        })
      })
      if (!resp.ok) throw new Error(`HTTP ${resp.status}`)
      const data = await resp.json()
      await loadMessages(sessionId)
      await loadSessions()
      return data.message
    } catch (e: any) {
      error.value = e.message || 'Failed to save message'
      return null
    } finally {
      loading.value = false
    }
  }

  async function updateMessage(sessionId: string, msgId: string, update: { role?: string; content?: string; results?: any }) {
    loading.value = true
    error.value = null
    try {
      const base = getApiBase()
      const resp = await fetch(`${base}/api/v2/search-sessions/${sessionId}/messages/${msgId}`, {
        method: 'PATCH',
        headers: { 'Content-Type': 'application/json', ...getAuthHeaders() },
        body: JSON.stringify({
          ...update,
          results: update.results ? JSON.stringify(update.results) : undefined
        })
      })
      if (!resp.ok) throw new Error(`HTTP ${resp.status}`)
      await loadMessages(sessionId)
    } catch (e: any) {
      error.value = e.message || 'Failed to update message'
    } finally {
      loading.value = false
    }
  }

  function setCurrentSession(session: SearchSession | null) {
    currentSession.value = session
    if (session) {
      loadMessages(session.id)
    } else {
      messages.value = []
    }
  }

  return {
    sessions,
    currentSession,
    messages,
    loading,
    error,
    loadSessions,
    createSession,
    renameSession,
    deleteSession,
    loadMessages,
    saveMessage,
    updateMessage,
    setCurrentSession
  }
}