/*
 *  conversationTools.ts
 *  Zyquo Cloud Web
 *
 *  Author: Simon-Pierre Boucher
 *  Mail: contact@spboucher.ai
 *
 *  Conversation-level tools: summarize (via the conversation's provider using
 *  its cheapest model) and context auto-trim (drop oldest turns, keep the
 *  system prompt, when near the window limit).
 */

import { cheapestModel, estimateTokens, findModel } from './catalogHelpers'
import { clientFor } from '../providers/registry'
import { uid, useStore } from '../state/store'
import { getKey } from '../storage/keys'
import type { Conversation, Message } from '../types'

/** Appends an assistant summary turn produced by the provider's cheapest model. */
export async function summarizeConversation(conversationID: string): Promise<void> {
  const state = useStore.getState()
  const conversation = state.conversations.find((c) => c.id === conversationID)
  if (!conversation || conversation.messages.length === 0) return
  const model =
    cheapestModel(conversation.provider) ?? findModel(conversation.provider, conversation.modelID)
  const apiKey = model ? getKey(model.provider) : undefined
  if (!model || !apiKey) {
    state.toast('No key available to summarize with', 'error')
    return
  }
  state.toast('Summarizing conversation…', 'info')
  const transcript = conversation.messages
    .filter((m) => !m.errorText)
    .map((m) => `${m.role === 'user' ? 'User' : 'Assistant'}: ${m.text.slice(0, 1500)}`)
    .join('\n\n')
  try {
    const result = await clientFor(model).complete(
      {
        model,
        messages: [
          {
            id: uid(),
            role: 'user',
            text: `Summarize this conversation in a concise bullet list (key points, decisions, open questions):\n\n${transcript.slice(0, 24_000)}`,
            createdAt: Date.now(),
          },
        ],
        parameters: { maxTokens: 600 },
        stream: false,
      },
      apiKey
    )
    const summary: Message = {
      id: uid(),
      role: 'assistant',
      text: `**Conversation summary**\n\n${result.text}`,
      modelID: model.id,
      provider: model.provider,
      createdAt: Date.now(),
    }
    state.updateConversation(conversationID, {
      messages: [...conversation.messages, summary],
    })
  } catch (err) {
    state.toast(err instanceof Error ? err.message : 'Summarize failed', 'error')
  }
}

/**
 * Auto-trim: when the estimated context usage exceeds ~90% of the model's
 * window, drops the oldest non-system turns (keeping the most recent ones)
 * and returns the trimmed message list for the request.
 */
export function autoTrimForContext(conversation: Conversation): {
  messages: Message[]
  trimmed: number
} {
  const model = findModel(conversation.provider, conversation.modelID)
  if (!model) return { messages: conversation.messages, trimmed: 0 }
  const budget = model.contextWindow * 0.9
  const systemTokens = estimateTokens(conversation.systemPrompt ?? '')
  const usable = conversation.messages.filter((m) => !m.errorText)
  let total = systemTokens + usable.reduce((sum, m) => sum + estimateTokens(m.text), 0)
  if (total <= budget) return { messages: conversation.messages, trimmed: 0 }
  const kept = [...usable]
  let trimmed = 0
  while (total > budget && kept.length > 2) {
    const dropped = kept.shift()
    if (!dropped) break
    total -= estimateTokens(dropped.text)
    trimmed++
  }
  return { messages: kept, trimmed }
}