// app/page.tsx
"use client";

import { useRouter } from "next/navigation";
import { useCallback, useMemo, useState } from "react";

import { Button } from "@/components/ui/button";
import { Card } from "@/components/ui/card";
import {
  Dialog,
  DialogContent,
  DialogFooter,
  DialogHeader,
  DialogTitle,
} from "@/components/ui/dialog";
import { Input } from "@/components/ui/input";
import { Separator } from "@/components/ui/separator";

type Mode = "freeflow" | "sprint" | "deepwork";

function modeLabel(mode: Mode) {
  switch (mode) {
    case "freeflow":
      return "프리플로우";
    case "sprint":
      return "스프린트";
    case "deepwork":
      return "딥워크";
  }
}

export default function HomePage() {
  const router = useRouter();

  const [open, setOpen] = useState(false);
  const [mode, setMode] = useState<Mode | null>(null);
  const [goal, setGoal] = useState("");

  const meta = useMemo(() => {
    if (!mode) return "";
    if (mode === "freeflow") return "무제한";
    if (mode === "sprint") return "25분";
    return "90분";
  }, [mode]);

  const go = useCallback(
    (mode: Mode, goal?: string) => {
      const params = new URLSearchParams();
      params.set("mode", mode);

      if (goal && goal.trim().length > 0) {
        localStorage.setItem("hushroom:session-goal", goal.trim());
      }

      router.push(`/session?${params.toString()}`);
    },
    [router],
  );

  const openDialog = (mode: Mode) => {
    setMode(mode);
    setGoal("");
    setOpen(true);
  };

  const start = () => {
    if (!mode) return;
    setOpen(false);
    go(mode, goal);
  };

  return (
    <main className="min-h-screen w-full bg-[#E9EEF6]">
      <header className="px-5 pt-6">
        <div className="select-none text-xl font-bold tracking-tight leading-none text-slate-800">
          hushroom
        </div>
      </header>

      <section className="mx-auto flex min-h-[calc(100vh-64px)] max-w-lg flex-col justify-center px-5 pb-10">
        <div className="mb-4">
          <div className="text-sm font-semibold text-slate-600">자유 세션</div>
          <div className="mt-1 text-base leading-relaxed text-slate-700">
            시간 제한 없이, 원할 때 종료 (60분 마다 노크합니다.)
          </div>
        </div>

        <Button
          type="button"
          onClick={() => openDialog("freeflow")}
          className="h-auto w-full items-start justify-start whitespace-normal rounded-3xl bg-[#2F6FED]
             px-8 py-6 text-left text-white shadow-sm transition active:scale-[0.99] hover:bg-[#295FD1]"
        >
          <div className="w-full">
            <div className="text-2xl font-semibold leading-none">
              프리플로우
            </div>
            <div className="mt-2 text-lg opacity-90">무제한</div>
          </div>
        </Button>

        <div className="my-8 flex items-center gap-3">
          <Separator className="flex-1 bg-[#D7E0EE]" />
          <div className="text-sm font-semibold text-slate-600">
            시간 고정 세션
          </div>
          <Separator className="flex-1 bg-[#D7E0EE]" />
        </div>

        <div className="-mt-2 mb-5 text-base leading-relaxed text-slate-700">
          한 번 실행되고 끝나면 요약으로 이동
        </div>

        {/* Sprint / Deepwork */}
        <div className="grid grid-cols-2 gap-4">
          <ModeTile
            title="스프린트"
            meta="25분"
            onClick={() => openDialog("sprint")}
          />
          <ModeTile
            title="딥워크"
            meta="90분"
            onClick={() => openDialog("deepwork")}
          />
        </div>
      </section>

      <SessionGoalDialog
        open={open}
        onOpenChange={setOpen}
        mode={mode}
        meta={meta}
        goal={goal}
        setGoal={setGoal}
        onStart={start}
      />
    </main>
  );
}

function ModeTile({
  title,
  meta,
  onClick,
}: {
  title: string;
  meta: string;
  onClick: () => void;
}) {
  return (
    <Card className="rounded-3xl border border-[#C9D7F5] bg-white shadow-sm transition hover:bg-[#F1F5FF]">
      <Button
        type="button"
        variant="ghost"
        onClick={onClick}
        className="h-auto w-full rounded-3xl px-7 text-left active:scale-[0.99]"
      >
        <div className="flex w-full items-baseline justify-between">
          <div className="text-xl font-semibold text-slate-900">{title}</div>
          <div className="text-lg font-semibold text-blue-700">{meta}</div>
        </div>
      </Button>
    </Card>
  );
}

function SessionGoalDialog({
  open,
  onOpenChange,
  mode,
  meta,
  goal,
  setGoal,
  onStart,
}: {
  open: boolean;
  onOpenChange: (v: boolean) => void;
  mode: Mode | null;
  meta: string;
  goal: string;
  setGoal: (v: string) => void;
  onStart: () => void;
}) {
  const title = mode ? `${modeLabel(mode)} · ${meta}` : "세션";

  return (
    <Dialog open={open} onOpenChange={onOpenChange}>
      <DialogContent className="sm:max-w-md rounded-2xl">
        <DialogHeader>
          <DialogTitle className="text-xl">세션 목표 설정</DialogTitle>
          <div className="text-sm text-slate-600">{title}</div>
        </DialogHeader>

        <div className="space-y-2">
          <Input
            value={goal}
            onChange={(e) => setGoal(e.target.value)}
            placeholder="목표를 입력하세요"
            className="text-lg"
            autoFocus
          />
          <div className="text-xs text-slate-500">
            짧게 적을수록 좋아요. 예: “이력서 1페이지”, “문제 10개”
          </div>
        </div>

        <DialogFooter className="gap-2 sm:gap-2">
          <Button variant="ghost" onClick={() => onOpenChange(false)}>
            취소
          </Button>
          <Button onClick={onStart} className="rounded-xl" disabled={!mode}>
            시작하기
          </Button>
        </DialogFooter>
      </DialogContent>
    </Dialog>
  );
}