/**
 * Chat Store – V2 Dashboard
 *
 * Fetches chat messages from /api/dashboard/chat/messages and
 * sends new messages via /api/dashboard/chat/send.
 *
 * Auto-refresh: every 10 seconds (incoming Iris messages).
 */
import { defineStore } from 'pinia'
import { apiFetch } from '../services/api'
import type { ChatMessage } from '../components/dashboard/v2/types'

/* ── API Response Shapes ──────────────────────────── */

interface MessageEntry {
  role: string
  content: string
  timestamp: string
}

interface ChatResponse {
  ok: boolean
  reply: string | null
  error: string | null
}

export const useChatStore = defineStore('chat', {
  state: () => ({
    messages: [] as ChatMessage[],
    isThinking: false,
    error: null as string | null,
    refreshInterval: null as ReturnType<typeof setInterval> | null,
    /** Tracks last process timestamp to avoid duplicates */
    lastProcessedTs: 0,
  }),

  getters: {
    messageList: (state) => state.messages,
  },

  actions: {
    /* ── API: Fetch history ─────────────────────── */
    async fetchHistory() {
      try {
        const res = await apiFetch('/api/dashboard/chat/messages?limit=50')
        if (!res.ok) return
        const data: MessageEntry[] = await res.json()

        // Merge new messages (avoid duplicates)
        let mostRecentTs = this.lastProcessedTs
        for (const msg of data) {
          const msgTs = new Date(msg.timestamp).getTime()
          if (msgTs <= this.lastProcessedTs) continue
          if (msgTs > mostRecentTs) mostRecentTs = msgTs

          const sender = msg.role === 'assistant' ? 'iris' as const : 'user' as const
          const tsFormatted = new Date(msg.timestamp).toLocaleTimeString('de-DE', {
            hour: '2-digit',
            minute: '2-digit',
          })

          // Avoid appending duplicates already present
          const exists = this.messages.some(
            m => m.sender === sender && m.text === msg.content && m.ts === tsFormatted
          )
          if (exists) continue

          this.messages.push({
            sender,
            text: msg.content,
            ts: tsFormatted,
          })
        }

        if (mostRecentTs > this.lastProcessedTs) {
          this.lastProcessedTs = mostRecentTs
        }
      } catch (err) {
        console.warn('[ChatStore] fetchHistory failed', err)
      }
    },

    /* ── API: Send message ──────────────────────── */
    async sendMessage(text: string) {
      if (!text.trim()) return

      const tsFormatted = new Date().toLocaleTimeString('de-DE', {
        hour: '2-digit',
        minute: '2-digit',
      })

      // Optimistic add: user message
      this.messages.push({
        sender: 'user',
        text: text.trim(),
        ts: tsFormatted,
      })

      this.isThinking = true
      this.error = null

      try {
        const res = await apiFetch('/api/dashboard/chat/send', {
          method: 'POST',
          body: JSON.stringify({ message: text.trim() }),
        })
        if (!res.ok) throw new Error(`HTTP ${res.status}`)
        const data: ChatResponse = await res.json()

        if (data.ok && data.reply) {
          this.messages.push({
            sender: 'iris',
            text: data.reply,
            ts: new Date().toLocaleTimeString('de-DE', {
              hour: '2-digit',
              minute: '2-digit',
            }),
          })
        } else if (data.error) {
          this.messages.push({
            sender: 'iris',
            text: `⚠️ ${data.error}`,
            ts: new Date().toLocaleTimeString('de-DE', {
              hour: '2-digit',
              minute: '2-digit',
            }),
          })
        }
      } catch (err) {
        console.warn('[ChatStore] sendMessage failed', err)
        this.messages.push({
          sender: 'iris',
          text: '⚠️ Connection error. Please try again.',
          ts: new Date().toLocaleTimeString('de-DE', {
            hour: '2-digit',
            minute: '2-digit',
          }),
        })
      } finally {
        this.isThinking = false
      }
    },

    /* ── Polling ─────────────────────────────────── */
    startPolling() {
      if (this.refreshInterval) return
      this.fetchHistory()
      this.refreshInterval = setInterval(() => {
        this.fetchHistory()
      }, 10000) // 10s for chat (more responsive)
    },

    stopPolling() {
      if (this.refreshInterval) {
        clearInterval(this.refreshInterval)
        this.refreshInterval = null
      }
    },
  },
})