import { useState, useCallback } from "react";
import { Page } from "@/components/layout/app-shell";
import { PageHeader } from "@/components/layout/page-header";
import { useQuery, useMutation } from "@tanstack/react-query";
import { useLocation } from "wouter";
import { CalendarClock, Upload, Loader2, Check, Link2 } from "lucide-react";
import { useDropzone } from "react-dropzone";
import { Button } from "@/components/ui/button";
import { Card, CardContent, CardDescription, CardHeader, CardTitle } from "@/components/ui/card";
import { Textarea } from "@/components/ui/textarea";
import { Label } from "@/components/ui/label";
import { Checkbox } from "@/components/ui/checkbox";
import { StoryToggle } from "@/components/reels/story-toggle";
import { useToast } from "@/hooks/use-toast";
import { apiRequest, queryClient, handleUnauthorized, getErrorMessage } from "@/lib/queryClient";
import type { SocialPage, Media } from "@shared/schema";
import { PlatformIcon } from "@/components/platform-icon";
import { EmptyState } from "@/components/empty-state";
import { MediaThumbnail } from "@/components/media-thumbnail";
import { DateTimePicker } from "@/components/datetime-picker";

/**
 * Programmation d'un Reel déjà monté : pas de rendu, la vidéo envoyée est
 * publiée telle quelle par le planificateur à la date choisie.
 */
export default function ScheduleReel() {
    const [, navigate] = useLocation();
    const { toast } = useToast();

    const [selectedVideo, setSelectedVideo] = useState<Media | null>(null);
    const [description, setDescription] = useState("");
    const [selectedPages, setSelectedPages] = useState<string[]>([]);
    const [scheduledDate, setScheduledDate] = useState<Date | undefined>(undefined);
    const [alsoStory, setAlsoStory] = useState(false);

    const { data: pages = [] } = useQuery<SocialPage[]>({ queryKey: ["/api/pages"] });
    const { data: allMedia = [] } = useQuery<Media[]>({ queryKey: ["/api/media"] });

    // Destinations acceptant un Reel
    const facebookPages = pages.filter((p) => p.platform === "facebook");
    const tiktokAccounts = pages.filter((p) => p.platform === "tiktok");
    const videoList = allMedia.filter((m) => m.type === "video").slice(0, 12);

    const uploadMutation = useMutation({
        mutationFn: async (file: File) => {
            const formData = new FormData();
            formData.append("file", file);
            const response = await fetch("/api/media/upload", {
                method: "POST",
                body: formData,
                credentials: "include",
            });
            if (!response.ok) {
                if (response.status === 401) handleUnauthorized("/api/media/upload");
                throw new Error("Upload failed");
            }
            return response.json() as Promise<Media>;
        },
        onSuccess: (media) => {
            queryClient.invalidateQueries({ queryKey: ["/api/media"] });
            setSelectedVideo(media);
            toast({ title: "Vidéo envoyée", description: media.fileName });
        },
        onError: () => {
            toast({ title: "Erreur", description: "Impossible d'envoyer la vidéo", variant: "destructive" });
        },
    });

    const onDrop = useCallback((files: File[]) => {
        if (files[0]) uploadMutation.mutate(files[0]);
    }, [uploadMutation]);

    const { getRootProps, getInputProps, isDragActive } = useDropzone({
        onDrop,
        accept: { "video/*": [".mp4", ".mov", ".webm"] },
        maxFiles: 1,
        disabled: uploadMutation.isPending,
    });

    const scheduleMutation = useMutation({
        mutationFn: async () => {
            const response = await apiRequest("POST", "/api/posts", {
                content: description,
                postType: "reel",
                mediaIds: [selectedVideo!.id],
                pageIds: selectedPages,
                scheduledFor: scheduledDate!.toISOString(),
                alsoStory,
            });
            return response.json();
        },
        onSuccess: async () => {
            await queryClient.invalidateQueries({ queryKey: ["/api/scheduled-posts"], refetchType: "all" });
            await queryClient.invalidateQueries({ queryKey: ["/api/posts"] });
            toast({ title: "Reel programmé", description: "Il sera publié à la date choisie." });
            navigate("/calendar");
        },
        onError: (error: unknown) => {
            toast({
                title: "Erreur",
                description: getErrorMessage(error, "Impossible de programmer le Reel"),
                variant: "destructive",
            });
        },
    });

    const isPast = !!scheduledDate && scheduledDate.getTime() <= Date.now();
    const canSchedule = !!selectedVideo && selectedPages.length > 0 && !!scheduledDate && !isPast;

    const togglePage = (id: string, checked: boolean) => {
        setSelectedPages((prev) => (checked ? [...prev, id] : prev.filter((p) => p !== id)));
    };

    const renderTargetCheckbox = (page: SocialPage) => {
        const checked = selectedPages.includes(page.id);
        return (
            <label
                key={page.id}
                htmlFor={`schedule-reel-page-${page.id}`}
                className={`flex cursor-pointer items-center gap-3 rounded-lg border p-3 transition-colors ${checked ? "border-primary bg-primary/5" : "hover:bg-accent"}`}
            >
                <PlatformIcon platform={page.platform} size="sm" />
                <span className="min-w-0 flex-1 truncate text-sm font-medium">{page.pageName}</span>
                <Checkbox
                    id={`schedule-reel-page-${page.id}`}
                    checked={checked}
                    onCheckedChange={(value) => togglePage(page.id, value === true)}
                />
            </label>
        );
    };

    const sectionTitle = (n: number, title: string, done: boolean) => (
        <CardTitle className="flex items-center gap-3">
            <span
                className={`flex h-7 w-7 shrink-0 items-center justify-center rounded-full text-xs font-semibold ${done ? "bg-primary text-primary-foreground" : "bg-primary/10 text-primary"}`}
            >
                {done ? <Check className="h-4 w-4" /> : n}
            </span>
            {title}
        </CardTitle>
    );

    return (
        <Page width="narrow">
                    <PageHeader
                        icon={CalendarClock}
                        title="Programmer un Reel"
                        description="Publiez une vidéo déjà montée, telle quelle, à la date et l'heure choisies."
                    />

                    <div className="space-y-6">
                    {/* 1. Vidéo */}
                    <Card>
                        <CardHeader>
                            {sectionTitle(1, "Vidéo", !!selectedVideo)}
                            <CardDescription>Format vertical 9:16 recommandé.</CardDescription>
                        </CardHeader>
                        <CardContent className="space-y-4">
                            <div
                                {...getRootProps()}
                                className={`border-2 border-dashed rounded-xl p-6 text-center cursor-pointer transition-colors ${
                                    isDragActive ? "border-primary bg-primary/5" : "border-border bg-muted/30 hover:border-primary/50"
                                }`}
                                data-testid="dropzone-schedule-reel"
                            >
                                <input {...getInputProps()} />
                                {uploadMutation.isPending ? (
                                    <div className="flex items-center justify-center gap-2 text-muted-foreground">
                                        <Loader2 className="w-5 h-5 animate-spin" /> Envoi en cours...
                                    </div>
                                ) : (
                                    <div className="space-y-1">
                                        <Upload className="w-8 h-8 mx-auto text-muted-foreground" />
                                        <p className="font-medium">Déposez votre Reel ici ou cliquez pour choisir</p>
                                        <p className="text-xs text-muted-foreground">MP4, MOV ou WebM</p>
                                    </div>
                                )}
                            </div>

                            {videoList.length > 0 && (
                                <div className="space-y-2">
                                    <Label>Ou choisissez une vidéo de la médiathèque</Label>
                                    <div className="grid grid-cols-3 sm:grid-cols-4 md:grid-cols-6 gap-2">
                                        {videoList.map((media) => {
                                            const selected = selectedVideo?.id === media.id;
                                            return (
                                                <button
                                                    key={media.id}
                                                    type="button"
                                                    onClick={() => setSelectedVideo(media)}
                                                    className={`relative aspect-[9/16] rounded-lg overflow-hidden border-2 ${
                                                        selected ? "border-primary" : "border-transparent"
                                                    }`}
                                                >
                                                    <MediaThumbnail
                                                        src={media.originalUrl}
                                                        alt={media.fileName}
                                                        thumbnailUrl={media.thumbnailUrl ?? undefined}
                                                        type="video"
                                                    />
                                                    {selected && (
                                                        <div className="absolute inset-0 bg-primary/30 flex items-center justify-center">
                                                            <Check className="w-6 h-6 text-primary-foreground" />
                                                        </div>
                                                    )}
                                                </button>
                                            );
                                        })}
                                    </div>
                                </div>
                            )}

                            {selectedVideo && (
                                <p className="text-sm text-muted-foreground">
                                    Sélectionnée : <span className="font-medium text-foreground">{selectedVideo.fileName}</span>
                                </p>
                            )}
                        </CardContent>
                    </Card>

                    {/* 2. Description */}
                    <Card>
                        <CardHeader>
                            {sectionTitle(2, "Description", !!description.trim())}
                            <CardDescription>Texte publié avec le Reel (facultatif).</CardDescription>
                        </CardHeader>
                        <CardContent>
                            <Textarea
                                value={description}
                                onChange={(e) => setDescription(e.target.value)}
                                placeholder="Texte publié avec le Reel (optionnel)"
                                rows={4}
                                data-testid="textarea-schedule-reel-description"
                            />
                        </CardContent>
                    </Card>

                    {/* 3. Destinations et date */}
                    <Card>
                        <CardHeader>
                            {sectionTitle(3, "Destinations et date", canSchedule)}
                        </CardHeader>
                        <CardContent className="space-y-6">
                            {facebookPages.length === 0 && tiktokAccounts.length === 0 && (
                                <EmptyState
                                    compact
                                    icon={Link2}
                                    title="Aucun compte connecté"
                                    description="Connectez une page Facebook ou un compte TikTok pour publier."
                                    action={<Button size="sm" onClick={() => navigate("/pages")}>Connecter un compte</Button>}
                                />
                            )}
                            {facebookPages.length > 0 && (
                                <div className="space-y-2">
                                    <p className="text-xs font-semibold uppercase tracking-wide text-muted-foreground">Pages Facebook</p>
                                    <div className="grid grid-cols-1 gap-2 sm:grid-cols-2">{facebookPages.map(renderTargetCheckbox)}</div>
                                    <StoryToggle checked={alsoStory} onCheckedChange={setAlsoStory} />
                                </div>
                            )}
                            {tiktokAccounts.length > 0 && (
                                <div className="space-y-2">
                                    <p className="text-xs font-semibold uppercase tracking-wide text-muted-foreground">Comptes TikTok</p>
                                    <div className="grid grid-cols-1 gap-2 sm:grid-cols-2">{tiktokAccounts.map(renderTargetCheckbox)}</div>
                                </div>
                            )}

                            <div className="space-y-2">
                                <Label>Date et heure de parution</Label>
                                <DateTimePicker
                                    value={scheduledDate}
                                    onChange={setScheduledDate}
                                    placeholder="Choisir la date et l'heure"
                                />
                                {isPast && (
                                    <p className="text-sm text-destructive">La date doit être dans le futur.</p>
                                )}
                            </div>

                            <Button
                                className="w-full"
                                size="lg"
                                variant="brand"
                                disabled={!canSchedule || scheduleMutation.isPending}
                                onClick={() => scheduleMutation.mutate()}
                                data-testid="button-schedule-reel"
                            >
                                {scheduleMutation.isPending ? (
                                    <Loader2 className="w-4 h-4 animate-spin" />
                                ) : (
                                    <CalendarClock className="w-4 h-4" />
                                )}
                                Programmer le Reel
                            </Button>
                        </CardContent>
                    </Card>
                    </div>
                </Page>
    );
}