import { useMutation, useQuery, useQueryClient } from "@tanstack/react-query"
import { useNavigate } from "@tanstack/react-router"
import { useEffect } from "react"

import { agentsApi } from "./api"
import type { ScheduleUpdateRequest } from "./api"
import type { AgentThread, Chunk, ImageChunk, Message } from "./types"

export const agentThreadKeys = {
  all: ["agent-threads"] as const,
  detail: (threadId: string) => ["agent-threads", threadId] as const,
  prDiff: (threadId: string) => ["agent-threads", threadId, "pr-diff"] as const,
}

export const agentScheduleKeys = {
  all: ["agent-schedules"] as const,
}

// The list endpoint (`GET /threads`) and the detail endpoint
// (`GET /threads/{id}`) return the same per-thread summary, so warming the
// detail cache from the already-fetched list avoids a fan-out of one request
// per sidebar thread. Navigation stays instant; the real (mark-viewed) fetch
// fires only when a thread is actually opened. The active thread is skipped so
// its live detail query stays the source of truth.
export function useSeedAgentThreadDetails(
  threads: Array<AgentThread>,
  activeThreadId?: string
) {
  const queryClient = useQueryClient()

  useEffect(() => {
    for (const thread of threads) {
      if (thread.id === activeThreadId) continue
      queryClient.setQueryData(agentThreadKeys.detail(thread.id), thread)
    }
  }, [activeThreadId, queryClient, threads])
}

export function useAgentThreads() {
  return useQuery({
    queryKey: agentThreadKeys.all,
    queryFn: () => agentsApi.listThreads(),
    refetchInterval: (query) =>
      query.state.data?.some((thread) => thread.status === "running")
        ? 2000
        : false,
  })
}

export function useAgentThread(threadId: string) {
  return useQuery({
    queryKey: agentThreadKeys.detail(threadId),
    queryFn: () => agentsApi.getThread(threadId),
  })
}

export function useAgentThreadPrDiff(threadId: string, enabled: boolean) {
  return useQuery({
    queryKey: agentThreadKeys.prDiff(threadId),
    queryFn: () => agentsApi.getThreadPrDiff(threadId),
    enabled,
    staleTime: 30_000,
    retry: false,
  })
}

export function useAgentSchedules() {
  return useQuery({
    queryKey: agentScheduleKeys.all,
    queryFn: () => agentsApi.listSchedules(),
  })
}

export function useCreateAgentSchedule() {
  const queryClient = useQueryClient()

  return useMutation({
    mutationFn: agentsApi.createSchedule,
    onSuccess: () => {
      queryClient.invalidateQueries({ queryKey: agentScheduleKeys.all })
    },
  })
}

export function useUpdateAgentSchedule() {
  const queryClient = useQueryClient()

  return useMutation({
    mutationFn: (vars: { scheduleId: string; body: ScheduleUpdateRequest }) =>
      agentsApi.updateSchedule(vars.scheduleId, vars.body),
    onSuccess: () => {
      queryClient.invalidateQueries({ queryKey: agentScheduleKeys.all })
    },
  })
}

export function useDeleteAgentSchedule() {
  const queryClient = useQueryClient()

  return useMutation({
    mutationFn: agentsApi.deleteSchedule,
    onSuccess: () => {
      queryClient.invalidateQueries({ queryKey: agentScheduleKeys.all })
    },
  })
}

export interface CreateAgentThreadVariables {
  prompt: string
  images?: Array<ImageChunk>
  repo?: string | null
  repo_explicitly_none?: boolean
  model_id?: string | null
  effort?: string | null
}

/**
 * Build the placeholder thread shown the instant a run is started from the
 * home page — before the server has stamped the thread record. Seeded into
 * the detail + list caches by `AgentsHome` so the `$threadId` route renders
 * immediately (the 30s `staleTime` keeps it from refetching into a 404), then
 * reconciled to server truth by the list's running refetch + the stream's
 * `onCreated` / `onCompleted` invalidations.
 */
export function optimisticThread(
  threadId: string,
  vars: CreateAgentThreadVariables
): AgentThread {
  const now = Date.now()
  const text = vars.prompt.trim()
  const repoFullName = vars.repo ?? ""
  const chunks: Array<Chunk> = [
    ...(vars.images ?? []),
    ...(text ? [{ kind: "text", text } satisfies Chunk] : []),
  ]
  const message: Message = {
    id: `optimistic-user-${threadId}`,
    author: "user",
    timestamp: new Date(now).toISOString(),
    chunks,
  }
  return {
    id: threadId,
    title: text.slice(0, 80) || "New agent",
    repo: repoFullName.split("/")[1] ?? "",
    repoFullName,
    branch: "main",
    model: vars.model_id ?? "Default",
    effort: vars.effort ?? null,
    source: "dashboard",
    status: "running",
    viewed: true,
    viewedAt: now,
    createdAt: now,
    updatedAt: now,
    traceUrl: null,
    messages: message.chunks.length > 0 ? [message] : [],
  }
}

export interface SendAgentMessageVariables {
  content: string
  images?: Array<ImageChunk>
  model_id?: string | null
  effort?: string | null
}

export function useCancelAgentThread(threadId: string) {
  const queryClient = useQueryClient()

  return useMutation({
    mutationFn: () => agentsApi.cancelThread(threadId),
    onSuccess: (thread) => {
      queryClient.setQueryData(agentThreadKeys.detail(threadId), thread)
      queryClient.invalidateQueries({ queryKey: agentThreadKeys.all, exact: true })
    },
  })
}

export function useDeleteAgentThread() {
  const queryClient = useQueryClient()
  const navigate = useNavigate()

  return useMutation({
    mutationFn: (threadId: string) => agentsApi.deleteThread(threadId),
    onSuccess: (_, threadId) => {
      queryClient.removeQueries({ queryKey: agentThreadKeys.detail(threadId) })
      queryClient.invalidateQueries({ queryKey: agentThreadKeys.all, exact: true })
      const path = window.location.pathname
      if (path.includes(`/agents/${threadId}`)) {
        navigate({ to: "/agents" })
      }
    },
  })
}