export const dynamic = 'force-dynamic'
export const runtime = 'nodejs'

import { NextResponse } from 'next/server'
import { HttpsProxyAgent } from 'https-proxy-agent'

import { voiceBus } from '@/lib/voice-bus'
import { systemPrompt } from '@/lib/voice-prompts'
import { TOOL_SCHEMAS, executeTool } from '@/lib/tools/_registry'
import { cleanForSpeech, stripFillers, isResetCommand } from '@/lib/voice-text'
import {
  loadHistory, saveHistory, resetHistory,
  HistoryMessage,
} from '@/lib/voice-history'

const MODEL = process.env.ANTHROPIC_MODEL || 'claude-haiku-4-5'
const MAX_TOKENS = parseInt(process.env.VOICE_MAX_TOKENS || '300', 10)
const MAX_TOOL_ROUNDS = 4
const RATE_LIMIT_PER_MINUTE = parseInt(process.env.VOICE_RATE_LIMIT || '20', 10)

const ANTHROPIC_API_KEY = process.env.ANTHROPIC_API_KEY || ''
const ANTHROPIC_PROXY = process.env.ANTHROPIC_PROXY || ''

// Rate limit
const rateBuckets = new Map<string, { count: number; resetAt: number }>()
function rateLimit(key: string): boolean {
  const now = Date.now()
  const b = rateBuckets.get(key)
  if (!b || b.resetAt <= now) {
    rateBuckets.set(key, { count: 1, resetAt: now + 60_000 })
    return true
  }
  if (b.count >= RATE_LIMIT_PER_MINUTE) return false
  b.count++
  return true
}
let lastSweep = 0
function sweep() {
  const now = Date.now()
  if (now - lastSweep < 5 * 60_000) return
  lastSweep = now
  for (const [k, v] of rateBuckets) if (v.resetAt <= now) rateBuckets.delete(k)
}

// Convert OpenAI-style tool schemas to Anthropic format
function toAnthropicTools(tools: any[]): any[] {
  return tools.map(t => ({
    name: t.function.name,
    description: t.function.description || '',
    input_schema: t.function.parameters || { type: 'object', properties: {} },
  }))
}

// Convert history to Anthropic messages format
function historyToAnthropicMessages(history: HistoryMessage[]): any[] {
  const result: any[] = []
  for (const msg of history) {
    if ((msg.role as string) === 'system') continue
    if (msg.role === 'user') {
      result.push({ role: 'user', content: msg.content || '' })
    } else if (msg.role === 'assistant') {
      if (msg.tool_calls && msg.tool_calls.length > 0) {
        const content: any[] = []
        if (msg.content) content.push({ type: 'text', text: msg.content })
        for (const tc of msg.tool_calls) {
          let input: any = {}
          try { input = JSON.parse(tc.function.arguments) } catch {}
          content.push({ type: 'tool_use', id: tc.id, name: tc.function.name, input })
        }
        result.push({ role: 'assistant', content })
      } else {
        result.push({ role: 'assistant', content: msg.content || '' })
      }
    } else if (msg.role === 'tool') {
      const last = result[result.length - 1]
      const toolResultBlock = {
        type: 'tool_result',
        tool_use_id: msg.tool_call_id,
        content: msg.content || '',
      }
      if (last && last.role === 'user' && Array.isArray(last.content)) {
        last.content.push(toolResultBlock)
      } else {
        result.push({ role: 'user', content: [toolResultBlock] })
      }
    }
  }
  return result
}

async function claudeRequest(system: string, messages: any[], tools?: any[]): Promise<any> {
  const body: any = {
    model: MODEL,
    max_tokens: MAX_TOKENS,
    system,
    messages,
  }
  if (tools && tools.length > 0) {
    body.tools = tools
  }

  const fetchOptions: any = {
    method: 'POST',
    headers: {
      'Content-Type': 'application/json',
      'x-api-key': ANTHROPIC_API_KEY,
      'anthropic-version': '2023-06-01',
    },
    body: JSON.stringify(body),
  }

  if (ANTHROPIC_PROXY) {
    fetchOptions.agent = new HttpsProxyAgent(ANTHROPIC_PROXY)
  }

  const res = await fetch('https://api.anthropic.com/v1/messages', fetchOptions)

  if (!res.ok) {
    const err = await res.text()
    throw new Error(`anthropic_${res.status}: ${err}`)
  }
  return res.json()
}

type AgentId = 'cosmo' | 'lusya'

function emitVoice(event: string, agent: AgentId, text?: string) {
  voiceBus.emit('voice', { event, agent, text, timestamp: new Date().toISOString() })
}

export async function POST(req: Request) {
  const cookie = req.headers.get('cookie') || ''
  const tokenMatch = cookie.match(/auth_token=([a-f0-9]{32,})/i)
  const internal = req.headers.get('x-voice-internal') || ''
  const fwd = req.headers.get('x-forwarded-for') || ''
  const ratekey = tokenMatch?.[1] || (internal ? 'internal' : '') || fwd.split(',')[0].trim() || 'anon'
  sweep()
  if (!rateLimit(ratekey)) {
    return NextResponse.json({ error: 'rate_limited' }, { status: 429 })
  }

  const body = await req.json().catch(() => null)
  if (!body || typeof body.text !== 'string' || !body.text.trim()) {
    return NextResponse.json({ error: 'text required' }, { status: 400 })
  }
  const userText: string = body.text.trim().slice(0, 4000)
  const agent: AgentId = body.agent === 'lusya' ? 'lusya' : 'cosmo'

  emitVoice('command', agent, userText)

  if (isResetCommand(userText)) {
    await resetHistory(agent)
    const msg = 'Начинаю новую сессию.'
    emitVoice('response', agent, msg)
    return NextResponse.json({ text: msg, reset: true })
  }

  const history = await loadHistory(agent)
  const sysPrompt = systemPrompt(agent)
  const anthropicTools = toAnthropicTools(TOOL_SCHEMAS as any[])

  const messages: any[] = [
    ...historyToAnthropicMessages(history),
    { role: 'user', content: userText },
  ]

  let finalText = ''
  const newTurns: HistoryMessage[] = [{ role: 'user', content: userText }]

  try {
    for (let round = 0; round < MAX_TOOL_ROUNDS; round++) {
      const t0 = Date.now()
      const resp = await claudeRequest(sysPrompt, messages, anthropicTools)

      console.log(
        `[voice/chat] ${agent} round ${round + 1} ${Date.now() - t0}ms · ` +
        `stop=${resp.stop_reason} · in=${resp.usage?.input_tokens} out=${resp.usage?.output_tokens}`
      )

      const content: any[] = resp.content || []
      const stopReason: string = resp.stop_reason || 'end_turn'

      if (stopReason === 'tool_use') {
        const toolUseBlocks = content.filter((b: any) => b.type === 'tool_use')
        const textBlocks = content.filter((b: any) => b.type === 'text')
        const partialText = textBlocks.map((b: any) => b.text).join('')

        messages.push({ role: 'assistant', content })
        newTurns.push({
          role: 'assistant',
          content: partialText || null,
          tool_calls: toolUseBlocks.map((b: any) => ({
            id: b.id,
            function: { name: b.name, arguments: JSON.stringify(b.input) },
          })),
        })

        const toolResults: any[] = []
        for (const tb of toolUseBlocks) {
          console.log(`[voice/chat] tool ${tb.name}(${JSON.stringify(tb.input).slice(0, 200)})`)
          const result = await executeTool(tb.name, tb.input || {}, agent)
          toolResults.push({
            type: 'tool_result',
            tool_use_id: tb.id,
            content: JSON.stringify(result),
          })
          newTurns.push({
            role: 'tool',
            content: JSON.stringify(result),
            tool_call_id: tb.id,
          })
        }

        messages.push({ role: 'user', content: toolResults })
        continue
      }

      const textBlocks = content.filter((b: any) => b.type === 'text')
      finalText = textBlocks.map((b: any) => b.text).join('')
      newTurns.push({ role: 'assistant', content: finalText })
      break
    }
  } catch (e: any) {
    const errStr = String(e?.message || e)
    console.error('[voice/chat] claude error:', errStr)
    const msg = 'Что-то сломалось.'
    emitVoice('error', agent, msg)
    return NextResponse.json({ error: 'llm_failed', detail: errStr, text: msg }, { status: 502 })
  }

  if (!finalText.trim()) {
    const msg = 'Не получил ответ.'
    emitVoice('error', agent, msg)
    return NextResponse.json({ text: msg }, { status: 200 })
  }

  const updatedHistory: HistoryMessage[] = [...history, ...newTurns]
  await saveHistory(agent, updatedHistory)

  const cleaned = cleanForSpeech(stripFillers(finalText))
  emitVoice('response', agent, cleaned)
  return NextResponse.json({ text: cleaned })
}
