"use client";

import { useCallback, useState } from "react";

import { api } from "@/lib/api/client";
import { useToast } from "@/components/Toast";
import type { ForeshadowView } from "@/lib/api/types";
import {
  buildRegisterRequest,
  buildTransitionRequest,
  extractReason,
  validationReasonMessage,
  type RegisterInput,
  type TransitionInput,
} from "./board";

export interface UseForeshadow {
  items: ForeshadowView[];
  busy: boolean;
  register: (input: RegisterInput) => Promise<boolean>;
  transition: (code: string, input: TransitionInput) => Promise<boolean>;
}

// 伏笔登记/状态变更（乐观更新 + 回滚 + Toast）。
// register：成功后把返回行追加进 items；422 duplicate → 友好提示，不改 items。
// transition：先乐观替换该行 status，失败回滚到旧 items 并 toast（读 details.reason）。
export function useForeshadow(initial: ForeshadowView[]): UseForeshadow {
  const [items, setItems] = useState<ForeshadowView[]>(initial);
  const [busy, setBusy] = useState(false);
  const toast = useToast();

  const register = useCallback<UseForeshadow["register"]>(
    async (input) => {
      setBusy(true);
      try {
        const { data, error } = await api.POST(
          "/projects/{project_id}/foreshadow",
          {
            params: { path: { project_id: input.projectId } },
            body: buildRegisterRequest(input),
          },
        );
        if (error || !data) {
          toast(validationReasonMessage(extractReason(error)), "error");
          return false;
        }
        setItems((prev) => [...prev, data]);
        toast(`已登记伏笔 ${data.code}`, "success");
        return true;
      } finally {
        setBusy(false);
      }
    },
    [toast],
  );

  const transition = useCallback<UseForeshadow["transition"]>(
    async (code, input) => {
      const snapshot = items;
      // 乐观：本地先改 status（若给了 toStatus）。
      if (input.toStatus) {
        const next = input.toStatus;
        setItems((prev) =>
          prev.map((it) => (it.code === code ? { ...it, status: next } : it)),
        );
      }
      setBusy(true);
      try {
        const { data, error } = await api.PATCH(
          "/projects/{project_id}/foreshadow/{code}",
          {
            params: {
              path: { project_id: input.projectId, code },
            },
            body: buildTransitionRequest(input),
          },
        );
        if (error || !data) {
          setItems(snapshot); // 回滚
          toast(validationReasonMessage(extractReason(error)), "error");
          return false;
        }
        // 用服务端权威行替换（status + progress 都对齐）。
        setItems((prev) => prev.map((it) => (it.code === code ? data : it)));
        toast(`已更新 ${data.code}`, "success");
        return true;
      } finally {
        setBusy(false);
      }
    },
    [items, toast],
  );

  return { items, busy, register, transition };
}