"use client";

import { useEffect, useState } from "react";
import {
  completeTask,
  createTask,
  failTask,
  fireTaskNow,
  listTasks,
  parseTask,
  type ParseTaskResult,
  type Task,
  type TaskType,
} from "../../lib/api";

const CHARACTER_ID = "seed-character-genki";
const USER_ID = "seed-user-primary";

const TASK_TYPE_LABELS: Record<TaskType, string> = {
  ONE_TIME: "單次提醒",
  RECURRING: "週期提醒",
  CONDITIONAL: "條件提醒",
  QUERY_ORGANIZE: "查資料／整理",
  TODO_TRACKING: "代辦追蹤",
};

const STATUS_LABELS: Record<Task["status"], string> = {
  PENDING: "尚未觸發",
  TRIGGERED: "已觸發，等候回應",
  COMPLETED: "已完成",
  FAILED: "失敗",
  CANCELLED: "已取消",
};

function isOverdue(task: Task): boolean {
  return task.status === "TRIGGERED" && task.overdueNudgeCount > 0;
}

// J-8 委託介面：自然語言輸入→（辨識成功即直接建立／辨識失敗則手動表單建立）→列表→觸發→完成或失敗，
// 對應計畫§委託子系統「角色不只陪聊，還能接受委託」。
export function TasksView() {
  const [text, setText] = useState("");
  const [tasks, setTasks] = useState<Task[]>([]);
  const [parseResult, setParseResult] = useState<ParseTaskResult | null>(null);
  const [manualDraft, setManualDraft] = useState<{ content: string; triggerAt: string } | null>(null);
  const [pending, setPending] = useState(false);
  const [error, setError] = useState<string | null>(null);

  async function refresh() {
    try {
      setTasks(await listTasks(CHARACTER_ID, USER_ID));
    } catch {
      setError("無法連線到 api 服務，委託清單暫時無法顯示");
    }
  }

  useEffect(() => {
    void refresh();
  }, []);

  async function handleParse() {
    const trimmed = text.trim();
    if (!trimmed || pending) {
      return;
    }
    setPending(true);
    setError(null);
    setParseResult(null);
    setManualDraft(null);
    try {
      const result = await parseTask(CHARACTER_ID, USER_ID, trimmed);
      setParseResult(result);
      if (result.created) {
        setText("");
        await refresh();
      } else {
        // 辨識失敗：退回手動表單，讓使用者自己補齊內容後透過 createTask() 建立。
        setManualDraft({ content: trimmed, triggerAt: "" });
      }
    } catch {
      setError("委託解析失敗，請確認 api 服務是否已啟動");
    } finally {
      setPending(false);
    }
  }

  async function handleManualCreate() {
    if (!manualDraft || !manualDraft.content.trim() || pending) {
      return;
    }
    setPending(true);
    setError(null);
    try {
      await createTask(CHARACTER_ID, USER_ID, {
        type: "TODO_TRACKING",
        content: manualDraft.content.trim(),
        rawText: text.trim() || manualDraft.content.trim(),
        triggerAt: manualDraft.triggerAt ? new Date(manualDraft.triggerAt).toISOString() : undefined,
      });
      setText("");
      setManualDraft(null);
      setParseResult(null);
      await refresh();
    } catch {
      setError("委託建立失敗，請確認 api 服務是否已啟動");
    } finally {
      setPending(false);
    }
  }

  async function handleAction(action: (taskId: string) => Promise<Task>, taskId: string) {
    setPending(true);
    setError(null);
    try {
      await action(taskId);
      await refresh();
    } catch {
      setError("操作失敗，請確認 api 服務是否已啟動");
    } finally {
      setPending(false);
    }
  }

  return (
    <div className="flex flex-col gap-4">
      <div className="flex flex-col gap-2 rounded-2xl border p-4" style={{ borderColor: "var(--line)" }}>
        <label className="text-xs" style={{ color: "var(--ink-soft)" }}>
          跟她說一句話，讓她幫你記著（例如「三點提醒我開會」）
        </label>
        <div className="flex gap-2">
          <input
            value={text}
            onChange={(event) => setText(event.target.value)}
            onKeyDown={(event) => {
              if (event.key === "Enter") {
                void handleParse();
              }
            }}
            placeholder="三點提醒我開會"
            className="flex-1 rounded-full border bg-transparent px-3 py-2 text-sm outline-none"
            style={{ borderColor: "var(--line)", color: "var(--ink)" }}
            disabled={pending}
          />
          <button
            type="button"
            onClick={() => void handleParse()}
            disabled={pending}
            className="rounded-full px-4 py-2 text-sm font-bold text-white disabled:opacity-50"
            style={{ background: "var(--accent-bright)" }}
          >
            送出
          </button>
        </div>

        {parseResult?.created && (
          <p className="text-xs" style={{ color: "var(--accent)" }}>
            已建立委託：{parseResult.task?.content}
            {parseResult.performanceLine ? `——${parseResult.performanceLine}` : ""}
          </p>
        )}

        {manualDraft && (
          <div className="flex flex-col gap-2 rounded-xl p-3 text-xs" style={{ background: "var(--bg-soft)" }}>
            <p style={{ color: "var(--ink-soft)" }}>沒辨識出明確時間，改用手動表單建立（分類為「代辦追蹤」）：</p>
            <input
              value={manualDraft.content}
              onChange={(event) => setManualDraft({ ...manualDraft, content: event.target.value })}
              placeholder="委託內容"
              className="rounded-full border bg-transparent px-3 py-1.5"
              style={{ borderColor: "var(--line)", color: "var(--ink)" }}
            />
            <input
              type="datetime-local"
              value={manualDraft.triggerAt}
              onChange={(event) => setManualDraft({ ...manualDraft, triggerAt: event.target.value })}
              className="rounded-full border bg-transparent px-3 py-1.5"
              style={{ borderColor: "var(--line)", color: "var(--ink)" }}
            />
            <button
              type="button"
              onClick={() => void handleManualCreate()}
              disabled={pending}
              className="self-start rounded-full px-4 py-1.5 font-bold text-white disabled:opacity-50"
              style={{ background: "var(--accent-bright)" }}
            >
              確認建立
            </button>
          </div>
        )}

        {error && (
          <p className="text-xs" style={{ color: "var(--accent)" }}>
            {error}
          </p>
        )}
      </div>

      <div className="flex flex-col gap-2">
        {tasks.length === 0 && (
          <p className="text-xs" style={{ color: "var(--ink-soft)" }}>
            目前沒有委託。
          </p>
        )}
        {tasks.map((task) => (
          <div key={task.id} className="flex flex-col gap-1.5 rounded-2xl border p-3 text-xs" style={{ borderColor: "var(--line)" }}>
            <div className="flex items-center justify-between">
              <span className="font-bold" style={{ color: "var(--ink)" }}>
                {task.content}
              </span>
              <span
                className="rounded-full px-2 py-0.5"
                style={{
                  background: isOverdue(task) ? "var(--accent-bright)" : "var(--chip-bg)",
                  color: isOverdue(task) ? "#fff" : "var(--accent)",
                }}
              >
                {isOverdue(task) ? "逾期未回應" : STATUS_LABELS[task.status]}
              </span>
            </div>
            <span style={{ color: "var(--ink-soft)" }}>
              {TASK_TYPE_LABELS[task.type]}
              {task.triggerAt ? `．${new Date(task.triggerAt).toLocaleString("zh-TW")}` : ""}
            </span>
            {task.triggerMessage && <span style={{ color: "var(--ink-soft)" }}>她說：{task.triggerMessage}</span>}

            {(task.status === "PENDING" || task.status === "TRIGGERED") && (
              <div className="flex gap-2 pt-1">
                {task.status === "PENDING" && (
                  <button
                    type="button"
                    onClick={() => void handleAction((id) => fireTaskNow(id).then(() => listTasks(CHARACTER_ID, USER_ID).then((all) => all.find((t) => t.id === id)!)), task.id)}
                    disabled={pending}
                    className="rounded-full border px-3 py-1 disabled:opacity-50"
                    style={{ borderColor: "var(--line)", color: "var(--ink-soft)" }}
                  >
                    立即觸發（測試用）
                  </button>
                )}
                <button
                  type="button"
                  onClick={() => void handleAction(completeTask, task.id)}
                  disabled={pending}
                  className="rounded-full px-3 py-1 font-bold text-white disabled:opacity-50"
                  style={{ background: "var(--accent-bright)" }}
                >
                  完成
                </button>
                <button
                  type="button"
                  onClick={() => void handleAction(failTask, task.id)}
                  disabled={pending}
                  className="rounded-full border px-3 py-1 disabled:opacity-50"
                  style={{ borderColor: "var(--line)", color: "var(--ink-soft)" }}
                >
                  失敗
                </button>
              </div>
            )}
          </div>
        ))}
      </div>
    </div>
  );
}