"use client";

import { useState } from "react";
import { BrainCircuit } from "lucide-react";
import { Button } from "@/components/ui/button";
import { Textarea } from "@/components/ui/textarea";
import { ZenCard } from "@/components/ui/zen-card";
import { ModeWorkspace } from "@/components/layout/mode-workspace";
import ResultAI from "@/components/result-ai";
import BaziChartDisplay from "@/components/modes/bazi-chart";
import LunarBirthPicker, {
  todaySolarYmd,
} from "@/components/shared/lunar-birth-picker";
import RegionSelect, {
  useRegionLocation,
} from "@/components/shared/region-select";
import { calculateBazi, type BaziChart } from "@/lib/calc/bazi";
import { streamAiCompletion } from "@/lib/ai/client-stream";
import { saveHistoryEntrySafe } from "@/lib/history/storage";

export default function BaziForm() {
  const [date, setDate] = useState(todaySolarYmd());
  const [time, setTime] = useState("12:00");
  const [unknownHour, setUnknownHour] = useState(false);
  const [gender, setGender] = useState<"male" | "female">("male");
  const [provinceCode, setProvinceCode] = useState("");
  const [cityCode, setCityCode] = useState("");
  const [question, setQuestion] = useState("");
  const [chart, setChart] = useState<BaziChart | null>(null);
  const [completion, setCompletion] = useState("");
  const [error, setError] = useState("");
  const [warning, setWarning] = useState("");
  const [isLoading, setIsLoading] = useState(false);

  const location = useRegionLocation(provinceCode, cityCode);

  function buildInput() {
    if (!location) {
      return null;
    }
    return {
      date,
      time: unknownHour ? "12:00" : time,
      gender,
      longitude: location.longitude,
      unknownHour,
    };
  }

  function handleCalculate() {
    const input = buildInput();
    if (!input) {
      setError("请选择出生地域");
      return;
    }
    if (!question.trim()) {
      setError("请输入问事");
      return;
    }
    setError("");
    setChart(calculateBazi(input));
    setCompletion("");
  }

  async function handleAnalyze() {
    const input = buildInput();
    if (!input) {
      setError("请选择出生地域");
      return;
    }
    if (!question.trim()) {
      setError("请输入问事");
      return;
    }
    const activeChart = chart ?? calculateBazi(input);
    if (!chart) {
      setChart(activeChart);
    }

    setError("");
    setWarning("");
    setCompletion("");
    setIsLoading(true);

    try {
      const text = await streamAiCompletion(
        {
          mode: "bazi",
          payload: {
            input,
            question,
            birthPlaceName: location!.name,
          },
        },
        setCompletion,
      );
      const saveResult = await saveHistoryEntrySafe({
        mode: "bazi",
        title: "生辰八字解读",
        question,
        summary: activeChart.lunarDate,
        completion: text,
        baziInput: {
          date: input.date,
          time: input.time,
          gender: input.gender,
          longitude: input.longitude,
          unknownHour: !!input.unknownHour,
          birthPlaceName: location!.name,
        },
        baziChart: activeChart,
        meta: {
          出生地域: location!.name,
          阳历生日: `${input.date} ${unknownHour ? "时辰不详" : input.time}`,
          农历: activeChart.lunarDate,
          性别: gender === "male" ? "男" : "女",
          四柱: `${activeChart.pillars.year.ganZhi} ${activeChart.pillars.month.ganZhi} ${activeChart.pillars.day.ganZhi} ${activeChart.pillars.time.ganZhi}`,
        },
      });
      if (!saveResult.ok) {
        setWarning(saveResult.error);
      }
    } catch (err) {
      setError(err instanceof Error ? err.message : String(err));
    } finally {
      setIsLoading(false);
    }
  }

  const activeChartPreview = chart;
  const downloadPreamble =
    completion && location
      ? `# 生辰八字 AI 解读\n\n- 问事：${question}\n- 出生地域：${location.name}\n- 阳历：${date} ${unknownHour ? "时辰不详" : time}\n${activeChartPreview ? `- 农历：${activeChartPreview.lunarDate}\n` : ""}`
      : undefined;

  return (
    <ModeWorkspace
      aiPanel={
        <ResultAI
          panel
          completion={completion}
          isLoading={isLoading}
          onCompletion={handleAnalyze}
          error={error}
          warning={warning}
          emptyHint="排盘后点击「AI 测算」获取解读"
          downloadFilename={completion ? "生辰八字解读.md" : undefined}
          downloadPreamble={downloadPreamble}
        />
      }
    >
      <ZenCard title="出生 · 命局" subtitle="四柱排盘所需信息" className="flex h-full min-h-0 flex-col">
        <LunarBirthPicker
          label="出生日期 / 时间"
          solarDate={date}
          time={time}
          timeDisabled={unknownHour}
          onSolarDateChange={setDate}
          onTimeChange={setTime}
        />
        <label className="flex items-center gap-2 text-xs text-muted-foreground">
          <input
            type="checkbox"
            checked={unknownHour}
            onChange={(e) => setUnknownHour(e.target.checked)}
          />
          时辰不详
        </label>
        <div className="flex gap-4">
          {(["male", "female"] as const).map((g) => (
            <label key={g} className="flex items-center gap-2 text-sm">
              <input
                type="radio"
                name="gender"
                checked={gender === g}
                onChange={() => setGender(g)}
              />
              {g === "male" ? "男" : "女"}
            </label>
          ))}
        </div>
        <RegionSelect
          label="出生地域"
          provinceCode={provinceCode}
          cityCode={cityCode}
          onProvinceChange={setProvinceCode}
          onCityChange={setCityCode}
        />
      </ZenCard>

      <ZenCard title="问事 · 排盘" subtitle="所求与命盘结果" className="flex h-full min-h-0 flex-col">
        <Textarea
          placeholder="事业、婚姻、健康等..."
          value={question}
          onChange={(e) => setQuestion(e.target.value)}
          rows={3}
          className="border-border/60 bg-background/50"
        />
        {error && !completion && (
          <p className="text-sm text-destructive">{error}</p>
        )}
        <div className="flex gap-2">
          <Button variant="outline" onClick={handleCalculate} className="flex-1">
            排盘
          </Button>
          <Button onClick={handleAnalyze} disabled={isLoading} className="flex-1">
            <BrainCircuit size={16} className="mr-1" />
            AI 测算
          </Button>
        </div>
        {chart && <BaziChartDisplay chart={chart} />}
      </ZenCard>
    </ModeWorkspace>
  );
}