import {
  buildFinanceChatMessages,
  buildTransactionEnrichmentMessages,
} from '../../lib/aiPrompt.js'
import { useSettingsStore } from '../../stores/settings.js'
import {
  applyAiEnrichment,
  fetchRecentTransactionsForAi,
  markTransactionAiFailed,
  markTransactionAiRunning,
} from '../transactionService.js'
import { DeepSeekProvider } from './deepseekProvider.js'

const clampThreshold = (value) => {
  const numeric = Number(value)
  if (!Number.isFinite(numeric)) return 0.9
  return Math.min(Math.max(numeric, 0), 1)
}

const createProvider = (settingsStore) => {
  if (settingsStore.aiProvider !== 'deepseek') {
    throw new Error(`Unsupported AI provider: ${settingsStore.aiProvider}`)
  }

  return new DeepSeekProvider({
    apiKey: settingsStore.aiApiKey,
    model: settingsStore.aiModel,
  })
}

export const hasAiAccess = (settingsStore = useSettingsStore()) => !!settingsStore.aiApiKey

export const isAiReady = (settingsStore = useSettingsStore()) =>
  !!settingsStore.aiAutoCategoryEnabled && hasAiAccess(settingsStore)

export const maybeEnrichTransactionWithAi = async (transaction, options = {}) => {
  if (!transaction?.id || transaction.entryType === 'transfer') return transaction

  const settingsStore = useSettingsStore()
  if (!isAiReady(settingsStore)) {
    return transaction
  }

  try {
    const running = await markTransactionAiRunning(transaction.id, settingsStore.aiModel)
    if (running) {
      options.onProgress?.(running)
    }

    const provider = createProvider(settingsStore)
    const similarTransactions = await fetchRecentTransactionsForAi(6, transaction.id)
    const messages = buildTransactionEnrichmentMessages({
      transaction,
      similarTransactions: similarTransactions.filter((item) => item.entryType !== 'transfer'),
    })
    const result = await provider.enrichTransaction({ messages })
    const threshold = clampThreshold(settingsStore.aiAutoApplyThreshold)

    const updated = await applyAiEnrichment(transaction.id, result.normalized, {
      applyCategory: result.normalized.confidence >= threshold,
      model: result.model,
    })

    return updated || transaction
  } catch (error) {
    console.warn('[ai] transaction enrichment failed', error)
    const failed = await markTransactionAiFailed(
      transaction.id,
      error?.message || 'AI enrichment failed',
      settingsStore.aiModel,
    )
    return failed || transaction
  }
}

export const askFinanceAssistant = async ({ question, transactions = [], conversation = [] }) => {
  const settingsStore = useSettingsStore()
  if (!hasAiAccess(settingsStore)) {
    throw new Error('请先在设置页填写 DeepSeek API Key')
  }

  const provider = createProvider(settingsStore)
  const messages = buildFinanceChatMessages({
    question,
    transactions,
    conversation,
  })

  return provider.chat({ messages })
}