import { useCallback, useEffect, useMemo, useRef } from 'react'
import { isFeedbackSurveyDisabled } from 'src/services/analytics/config.js'
import { getFeatureValue_CACHED_MAY_BE_STALE } from 'src/services/analytics/growthbook.js'
import {
  type AnalyticsMetadata_I_VERIFIED_THIS_IS_NOT_CODE_OR_FILEPATHS,
  logEvent,
} from 'src/services/analytics/index.js'
import { isAutoMemoryEnabled } from '../../memdir/paths.js'
import { isPolicyAllowed } from '../../services/policyLimits/index.js'
import { FILE_READ_TOOL_NAME } from '../../tools/FileReadTool/prompt.js'
import type { Message } from '../../types/message.js'
import { getGlobalConfig, saveGlobalConfig } from '../../utils/config.js'
import { isEnvTruthy } from '../../utils/envUtils.js'
import { isAutoManagedMemoryFile } from '../../utils/memoryFileDetection.js'
import {
  extractTextContent,
  getLastAssistantMessage,
} from '../../utils/messages.js'
import { logOTelEvent } from '../../utils/telemetry/events.js'
import { submitTranscriptShare } from './submitTranscriptShare.js'
import type { TranscriptShareResponse } from './TranscriptSharePrompt.js'
import { useSurveyState } from './useSurveyState.js'
import type { FeedbackSurveyResponse } from './utils.js'

const HIDE_THANKS_AFTER_MS = 3000
const MEMORY_SURVEY_GATE = 'tengu_dunwich_bell'
const MEMORY_SURVEY_EVENT = 'tengu_memory_survey_event'
const SURVEY_PROBABILITY = 0.2
const TRANSCRIPT_SHARE_TRIGGER = 'memory_survey'

const MEMORY_WORD_RE = /\bmemor(?:y|ies)\b/i

function hasMemoryFileRead(messages: Message[]): boolean {
  for (const message of messages) {
    if (message.type !== 'assistant') {
      continue
    }
    const content = message.message!.content
    if (!Array.isArray(content)) {
      continue
    }
    for (const block of content) {
      if (block.type !== 'tool_use' || block.name !== FILE_READ_TOOL_NAME) {
        continue
      }
      const input = block.input as { file_path?: unknown }
      if (
        typeof input.file_path === 'string' &&
        isAutoManagedMemoryFile(input.file_path)
      ) {
        return true
      }
    }
  }
  return false
}

export function useMemorySurvey(
  messages: Message[],
  isLoading: boolean,
  hasActivePrompt = false,
  { enabled = true }: { enabled?: boolean } = {},
): {
  state:
    | 'closed'
    | 'open'
    | 'thanks'
    | 'transcript_prompt'
    | 'submitting'
    | 'submitted'
  lastResponse: FeedbackSurveyResponse | null
  handleSelect: (selected: FeedbackSurveyResponse) => void
  handleTranscriptSelect: (selected: TranscriptShareResponse) => void
} {
  // Track assistant message UUIDs that were already evaluated so we don't
  // re-roll probability on re-renders or re-scan messages for the same turn.
  const seenAssistantUuids = useRef<Set<string>>(new Set())
  // Once a memory file read is observed it stays true for the session —
  // skip the O(n) scan on subsequent turns.
  const memoryReadSeen = useRef(false)
  const messagesRef = useRef(messages)
  messagesRef.current = messages

  const onOpen = useCallback((appearanceId: string) => {
    logEvent(MEMORY_SURVEY_EVENT, {
      event_type:
        'appeared' as AnalyticsMetadata_I_VERIFIED_THIS_IS_NOT_CODE_OR_FILEPATHS,
      appearance_id:
        appearanceId as AnalyticsMetadata_I_VERIFIED_THIS_IS_NOT_CODE_OR_FILEPATHS,
    })
    void logOTelEvent('feedback_survey', {
      event_type: 'appeared',
      appearance_id: appearanceId,
      survey_type: 'memory',
    })
  }, [])

  const onSelect = useCallback(
    (appearanceId: string, selected: FeedbackSurveyResponse) => {
      logEvent(MEMORY_SURVEY_EVENT, {
        event_type:
          'responded' as AnalyticsMetadata_I_VERIFIED_THIS_IS_NOT_CODE_OR_FILEPATHS,
        appearance_id:
          appearanceId as AnalyticsMetadata_I_VERIFIED_THIS_IS_NOT_CODE_OR_FILEPATHS,
        response:
          selected as AnalyticsMetadata_I_VERIFIED_THIS_IS_NOT_CODE_OR_FILEPATHS,
      })
      void logOTelEvent('feedback_survey', {
        event_type: 'responded',
        appearance_id: appearanceId,
        response: selected,
        survey_type: 'memory',
      })
    },
    [],
  )

  const shouldShowTranscriptPrompt = useCallback(
    (selected: FeedbackSurveyResponse) => {
      if (process.env.USER_TYPE !== 'ant') {
        return false
      }
      if (selected !== 'bad' && selected !== 'good') {
        return false
      }
      if (getGlobalConfig().transcriptShareDismissed) {
        return false
      }
      if (!isPolicyAllowed('allow_product_feedback')) {
        return false
      }
      return true
    },
    [],
  )

  const onTranscriptPromptShown = useCallback((appearanceId: string) => {
    logEvent(MEMORY_SURVEY_EVENT, {
      event_type:
        'transcript_prompt_appeared' as AnalyticsMetadata_I_VERIFIED_THIS_IS_NOT_CODE_OR_FILEPATHS,
      appearance_id:
        appearanceId as AnalyticsMetadata_I_VERIFIED_THIS_IS_NOT_CODE_OR_FILEPATHS,
      trigger:
        TRANSCRIPT_SHARE_TRIGGER as AnalyticsMetadata_I_VERIFIED_THIS_IS_NOT_CODE_OR_FILEPATHS,
    })
    void logOTelEvent('feedback_survey', {
      event_type: 'transcript_prompt_appeared',
      appearance_id: appearanceId,
      survey_type: 'memory',
    })
  }, [])

  const onTranscriptSelect = useCallback(
    async (
      appearanceId: string,
      selected: TranscriptShareResponse,
    ): Promise<boolean> => {
      logEvent(MEMORY_SURVEY_EVENT, {
        event_type:
          `transcript_share_${selected}` as AnalyticsMetadata_I_VERIFIED_THIS_IS_NOT_CODE_OR_FILEPATHS,
        appearance_id:
          appearanceId as AnalyticsMetadata_I_VERIFIED_THIS_IS_NOT_CODE_OR_FILEPATHS,
        trigger:
          TRANSCRIPT_SHARE_TRIGGER as AnalyticsMetadata_I_VERIFIED_THIS_IS_NOT_CODE_OR_FILEPATHS,
      })

      if (selected === 'dont_ask_again') {
        saveGlobalConfig(current => ({
          ...current,
          transcriptShareDismissed: true,
        }))
      }

      if (selected === 'yes') {
        const result = await submitTranscriptShare(
          messagesRef.current,
          TRANSCRIPT_SHARE_TRIGGER,
          appearanceId,
        )
        logEvent(MEMORY_SURVEY_EVENT, {
          event_type: (result.success
            ? 'transcript_share_submitted'
            : 'transcript_share_failed') as AnalyticsMetadata_I_VERIFIED_THIS_IS_NOT_CODE_OR_FILEPATHS,
          appearance_id:
            appearanceId as AnalyticsMetadata_I_VERIFIED_THIS_IS_NOT_CODE_OR_FILEPATHS,
          trigger:
            TRANSCRIPT_SHARE_TRIGGER as AnalyticsMetadata_I_VERIFIED_THIS_IS_NOT_CODE_OR_FILEPATHS,
        })
        return result.success
      }

      return false
    },
    [],
  )

  const { state, lastResponse, open, handleSelect, handleTranscriptSelect } =
    useSurveyState({
      hideThanksAfterMs: HIDE_THANKS_AFTER_MS,
      onOpen,
      onSelect,
      shouldShowTranscriptPrompt,
      onTranscriptPromptShown,
      onTranscriptSelect,
    })

  const lastAssistant = useMemo(
    () => getLastAssistantMessage(messages),
    [messages],
  )

  useEffect(() => {
    if (!enabled) return

    // /clear resets messages but REPL stays mounted — reset refs so a memory
    // read from the previous conversation doesn't leak into the new one.
    if (messages.length === 0) {
      memoryReadSeen.current = false
      seenAssistantUuids.current.clear()
      return
    }

    if (state !== 'closed' || isLoading || hasActivePrompt) {
      return
    }

    // 3P default: survey off (no GrowthBook on Bedrock/Vertex/Foundry).
    if (!getFeatureValue_CACHED_MAY_BE_STALE(MEMORY_SURVEY_GATE, false)) {
      return
    }

    if (!isAutoMemoryEnabled()) {
      return
    }

    if (isFeedbackSurveyDisabled()) {
      return
    }

    if (!isPolicyAllowed('allow_product_feedback')) {
      return
    }

    if (isEnvTruthy(process.env.CLAUDE_CODE_DISABLE_FEEDBACK_SURVEY)) {
      return
    }

    if (!lastAssistant || seenAssistantUuids.current.has(lastAssistant.uuid)) {
      return
    }

    const text = extractTextContent(Array.isArray(lastAssistant.message.content) ? lastAssistant.message.content : [], ' ')
    if (!MEMORY_WORD_RE.test(text)) {
      return
    }

    // Mark as evaluated before the memory-read scan so a turn that mentions
    // "memory" but has no memory read doesn't trigger repeated O(n) scans
    // on subsequent renders with the same last assistant message.
    seenAssistantUuids.current.add(lastAssistant.uuid)

    if (!memoryReadSeen.current) {
      memoryReadSeen.current = hasMemoryFileRead(messages)
    }
    if (!memoryReadSeen.current) {
      return
    }

    if (Math.random() < SURVEY_PROBABILITY) {
      open()
    }
  }, [
    enabled,
    state,
    isLoading,
    hasActivePrompt,
    lastAssistant,
    messages,
    open,
  ])

  return { state, lastResponse, handleSelect, handleTranscriptSelect }
}