import { useState, useEffect } from "react";
import { Badge } from "@/components/ui/badge";
import { ClipboardCheck, CheckCheck, SendHorizonal, Lock, Zap, Info, Tag } from "lucide-react";
import { ScrollArea, ScrollBar } from "@/components/ui/scroll-area";
import ResponsiveModal from "@/components/generic/ResponsiveModal";
import { Button } from "@/components/ui/button";
import { useNavigate } from "react-router-dom";
import api from "@/utils/api.util";
import { useClientTiers } from "@/contexts/ClientTiersProvider";
import { resolveTierBadge } from "@/utils/tierBadge.util";

function TierBadge({ tier }) {
    const { tierMap } = useClientTiers();
    const { rank, label, cls } = resolveTierBadge(tier ?? 'free', tierMap);
    return (
        <Badge className={`gap-1 ${cls} w-fit shrink-0`}>
            {rank > 0 ? <Lock className="size-3" /> : <Tag className="size-3" />}
            {label}
        </Badge>
    );
}

// ─── PassQuiz — task requirement block for pass_quiz type ─────────────────────
// Mirrors ReadUnit.jsx's fetch-detail-and-navigate pattern. A quiz is always
// unit-scoped; navigation goes into the course reader if the unit is attached
// to a course, otherwise the standalone unit reader.
const PassQuiz = ({ title = "Pass Quizzes", quizzes = [], groupId, taskListId, taskId }) => {
    const navigate = useNavigate();
    const [details,     setDetails]     = useState({});
    const [locked,      setLocked]      = useState({});
    const [lockedInfo,  setLockedInfo]  = useState({});
    const [unavailable, setUnavailable] = useState({});
    const [fetching,    setFetching]    = useState({});
    const [selected,    setSelected]    = useState(null);

    useEffect(() => {
        quizzes.forEach(async (q) => {
            if (!q.reference_id) return;
            setFetching((prev) => ({ ...prev, [q.reference_id]: true }));
            try {
                const res = await api.get(`/client/courses/quiz/uuid/${q.reference_id}`);
                const d   = res.data?.data;
                if (d) setDetails((prev) => ({ ...prev, [q.reference_id]: d }));
            } catch (err) {
                if (err?.response?.status === 403) {
                    setLocked((prev) => ({ ...prev, [q.reference_id]: true }));
                    const course = err.response?.data?.course;
                    if (course) setLockedInfo((prev) => ({ ...prev, [q.reference_id]: course }));
                } else {
                    setUnavailable((prev) => ({ ...prev, [q.reference_id]: true }));
                }
            } finally {
                setFetching((prev) => ({ ...prev, [q.reference_id]: false }));
            }
        });
    }, []);

    const goToQuiz = (info) => {
        if (!info) return;
        const taskCtx = taskId ? { has_task: true, groupId, taskListId, taskId } : undefined;
        if (info.unit?.course?.course_id) {
            navigate(`/course/${info.unit.course.course_id}/unit`, {
                state: { quizUnitId: info.unit.unit_id, ...(taskCtx ? { taskCtx } : {}) },
            });
        } else if (info.unit?.uuid) {
            navigate(`/units/${info.unit.uuid}/read`, { state: { quizId: true } });
        }
    };

    if (!quizzes.length) return null;

    const hasLocked = Object.values(locked).some(Boolean);

    return (
        <>
            <div className="border rounded-lg bg-card overflow-hidden">
                <div className="px-6 py-4 border-b flex items-center gap-2">
                    <ClipboardCheck className="size-4 text-muted-foreground" />
                    <h2 className="font-semibold text-sm">{title}</h2>
                    <Badge variant="secondary" className="ml-auto">{quizzes.length}</Badge>
                </div>

                {hasLocked && (
                    <div className="flex items-start gap-3 px-5 py-3.5 border-b bg-amber-50 dark:bg-amber-950/30 text-amber-800 dark:text-amber-300">
                        <Info className="size-4 mt-0.5 shrink-0" />
                        <div className="flex-1 min-w-0">
                            <p className="text-sm font-medium leading-snug">Subscription Required</p>
                            <p className="text-xs mt-0.5 text-amber-700 dark:text-amber-400 leading-relaxed">
                                To complete this activity, subscribe to one of our available tier plans.
                            </p>
                        </div>
                        <Button size="sm" variant="outline" className="shrink-0 border-amber-300 dark:border-amber-700 text-amber-800 dark:text-amber-300 hover:bg-amber-100 dark:hover:bg-amber-900/40" onClick={() => navigate('/plans')}>
                            <Zap className="size-3.5" /> View Plans
                        </Button>
                    </div>
                )}

                <ScrollArea className="w-full bg-muted overflow-hidden">
                    <div className="flex gap-4 p-4">
                        {quizzes.map((q) => {
                            const info          = details[q.reference_id];
                            const courseInfo    = lockedInfo[q.reference_id];
                            const isLocked      = locked[q.reference_id];
                            const isUnavailable = unavailable[q.reference_id];
                            const isFetching    = fetching[q.reference_id];
                            const passed        = info?.has_passed || q.completed;

                            if (isLocked) {
                                return (
                                    <div
                                        key={q.id}
                                        onClick={() => navigate('/plans')}
                                        className="bg-card rounded-2xl border border-dashed p-4 flex flex-col gap-3 hover:bg-muted/60 hover:shadow-sm transition-all cursor-pointer group w-80 shrink-0 opacity-80"
                                    >
                                        <div className="flex items-center gap-1.5">
                                            <ClipboardCheck className="size-3.5 text-muted-foreground shrink-0" />
                                            <span className="text-xs text-muted-foreground font-medium">Quiz</span>
                                            <div className="ml-auto"><TierBadge tier={courseInfo?.subscription} /></div>
                                        </div>
                                        <h1 className="text-base font-semibold leading-snug line-clamp-2 text-muted-foreground">{q.title}</h1>
                                        <p className="text-sm text-muted-foreground">
                                            Subscribe to <span className="font-medium">{courseInfo?.title ?? 'this course'}</span> to unlock this quiz.
                                        </p>
                                        <div className="mt-auto">
                                            <Button size="sm" className="w-full gap-1.5" onClick={(e) => { e.stopPropagation(); navigate('/plans'); }}>
                                                <Zap className="size-3.5" /> Upgrade to unlock
                                            </Button>
                                        </div>
                                    </div>
                                );
                            }

                            if (isUnavailable) {
                                return (
                                    <div key={q.id} className="bg-card rounded-2xl border border-dashed p-4 flex flex-col gap-3 w-80 shrink-0 opacity-50 cursor-not-allowed">
                                        <div className="flex items-center gap-1.5">
                                            <ClipboardCheck className="size-3.5 text-muted-foreground shrink-0" />
                                            <span className="text-xs text-muted-foreground font-medium">Quiz</span>
                                            <Badge variant="secondary" className="ml-auto gap-1 text-muted-foreground text-xs">
                                                <Lock className="size-3" /> Unavailable
                                            </Badge>
                                        </div>
                                        <h1 className="text-base font-semibold leading-snug line-clamp-2 text-muted-foreground">{q.title}</h1>
                                        <p className="text-sm text-muted-foreground">This quiz is no longer available.</p>
                                    </div>
                                );
                            }

                            return (
                                <div
                                    key={q.id}
                                    onClick={() => !isFetching && setSelected(q)}
                                    className={`bg-card rounded-2xl border p-4 flex flex-col gap-3 transition-all w-80 shrink-0 ${
                                        isFetching ? 'opacity-60 cursor-wait' : 'hover:bg-muted/60 hover:shadow-sm cursor-pointer group'
                                    }`}
                                >
                                    <div className="flex items-center gap-1.5">
                                        <ClipboardCheck className="size-3.5 text-muted-foreground shrink-0" />
                                        <span className="text-xs text-muted-foreground font-medium">Quiz</span>
                                        <div className="ml-auto">
                                            {info?.unit?.course?.subscription
                                                ? <TierBadge tier={info.unit.course.subscription} />
                                                : isFetching && <Badge variant="secondary" className="opacity-40 text-xs">Loading…</Badge>
                                            }
                                        </div>
                                    </div>
                                    {info?.unit?.title && (
                                        <p className="text-xs text-muted-foreground truncate -mt-1">
                                            in <span className="text-foreground/70 font-medium">{info.unit.title}</span>
                                        </p>
                                    )}
                                    <h1 className="text-base font-semibold leading-snug line-clamp-2">{q.title}</h1>
                                    <div className="flex items-center justify-between text-sm mt-auto pt-2 border-t">
                                        {passed ? (
                                            <span className="flex items-center gap-1.5 text-green-600 dark:text-green-400 font-medium">
                                                <CheckCheck className="size-4" /> Passed
                                            </span>
                                        ) : (
                                            <span className="text-muted-foreground font-medium">Not Attempted</span>
                                        )}
                                        {info?.passing_score && (
                                            <span className="text-xs text-muted-foreground">{info.passing_score}% to pass</span>
                                        )}
                                    </div>
                                </div>
                            );
                        })}
                    </div>
                    <ScrollBar orientation="horizontal" />
                </ScrollArea>
            </div>

            <ResponsiveModal
                open={!!selected}
                onOpenChange={(v) => !v && setSelected(null)}
                title={selected?.title}
                description="Quiz Info"
                footer={
                    <>
                        <Button variant="outline" onClick={() => setSelected(null)}>Cancel</Button>
                        <Button
                            onClick={() => goToQuiz(details[selected?.reference_id])}
                            disabled={!details[selected?.reference_id]}
                        >
                            <SendHorizonal /> Take Quiz
                        </Button>
                    </>
                }
            >
                {selected && (() => {
                    const info = details[selected.reference_id];
                    return (
                        <div className="flex flex-col gap-4">
                            {(info?.has_passed || selected.completed) && (
                                <div className="flex items-center gap-2 bg-green-50 dark:bg-green-950/40 text-green-700 dark:text-green-400 text-sm font-medium rounded-lg px-4 py-3">
                                    <CheckCheck className="size-4 shrink-0" /> Already Passed
                                </div>
                            )}
                            {info?.unit?.title && (
                                <p className="text-sm">
                                    <span className="text-muted-foreground">Unit: </span>
                                    <span className="font-medium">{info.unit.title}</span>
                                </p>
                            )}
                            {info?.passing_score && (
                                <p className="text-sm">
                                    <span className="text-muted-foreground">Passing score: </span>
                                    <span className="font-medium">{info.passing_score}%</span>
                                </p>
                            )}
                        </div>
                    );
                })()}
            </ResponsiveModal>
        </>
    );
};

export default PassQuiz;