'use client';

import { useState } from 'react';
import { useRouter } from 'next/navigation';
import { toast } from 'sonner';
import {
    Video,
    Building2,
    FolderPlus,
    PlayCircle,
    Bell,
    ChevronRight,
    Loader2,
    Lock,
    UserPlus,
    Globe,
    Youtube,
    Upload,
    Mail,
    AlertCircle,
    Info,
} from 'lucide-react';
import { Button } from '@/components/ui/button';
import { Card, CardContent } from '@/components/ui/card';
import { Input } from '@/components/ui/input';
import { Label } from '@/components/ui/label';
import { Textarea } from '@/components/ui/textarea';
import { cn } from '@/lib/utils';

type Visibility = 'PRIVATE' | 'INVITE' | 'PUBLIC';

const TOTAL_STEPS = 5;

const visibilityOptions: { value: Visibility; label: string; description: string; icon: React.ReactNode }[] = [
    {
        value: 'PRIVATE',
        label: 'Private',
        description: 'Only workspace members and project members can access',
        icon: <Lock className="h-5 w-5" />,
    },
    {
        value: 'INVITE',
        label: 'Invite Only',
        description: 'Share with specific people via email',
        icon: <UserPlus className="h-5 w-5" />,
    },
    {
        value: 'PUBLIC',
        label: 'Public',
        description: 'Anyone with the link can view',
        icon: <Globe className="h-5 w-5" />,
    },
];

function ToggleButton({
    enabled,
    onToggle,
    label,
    description,
}: {
    enabled: boolean;
    onToggle: () => void;
    label: string;
    description?: string;
}) {
    return (
        <button
            type="button"
            onClick={onToggle}
            className={cn(
                'flex items-center justify-between w-full p-3 rounded-lg border transition-colors text-left',
                enabled ? 'border-primary/50 bg-primary/5' : 'border-border hover:bg-accent/50'
            )}
        >
            <div className="flex-1 min-w-0 pr-4">
                <span className="text-sm font-medium">{label}</span>
                {description && (
                    <p className="text-xs text-muted-foreground mt-0.5">{description}</p>
                )}
            </div>
            <div className={cn('w-10 h-6 shrink-0 rounded-full relative transition-colors', enabled ? 'bg-primary' : 'bg-muted')}>
                <div className={cn('absolute top-1 w-4 h-4 rounded-full bg-white transition-transform', enabled ? 'translate-x-5' : 'translate-x-1')} />
            </div>
        </button>
    );
}

// ─── Step 1: Welcome ───────────────────────────────────────────────────────────

function StepWelcome({ userName, onNext }: { userName: string; onNext: () => void }) {
    return (
        <div className="text-center space-y-8">
            <div className="mx-auto w-24 h-24 rounded-full bg-primary/10 flex items-center justify-center">
                <Video className="h-12 w-12 text-primary" />
            </div>
            <div className="space-y-3">
                <h2 className="text-3xl font-bold tracking-tight">Welcome to OpenFrame, {userName.split(' ')[0]}!</h2>
                <p className="text-base text-muted-foreground max-w-md mx-auto">
                    OpenFrame is your collaborative video review platform. Collect timestamped feedback, manage versions, and streamline approvals — all in one place.
                </p>
            </div>
            <Button onClick={onNext} size="lg" className="w-full sm:w-auto px-10 h-12 text-base">
                Get Started
                <ChevronRight className="h-5 w-5 ml-1" />
            </Button>
        </div>
    );
}

// ─── Step 2: Create Workspace ──────────────────────────────────────────────────

function StepWorkspace({
    onNext,
    onWorkspaceCreated,
}: {
    onNext: () => void;
    onWorkspaceCreated: (id: string) => void;
}) {
    const [isLoading, setIsLoading] = useState(false);
    const [error, setError] = useState('');
    const [formData, setFormData] = useState({ name: '', description: '' });

    const handleSubmit = async (e: React.FormEvent) => {
        e.preventDefault();
        setIsLoading(true);
        setError('');
        try {
            const res = await fetch('/api/workspaces', {
                method: 'POST',
                headers: { 'Content-Type': 'application/json' },
                body: JSON.stringify(formData),
            });
            const data = await res.json();
            if (!res.ok) {
                setError(data.error || 'Failed to create workspace');
                return;
            }
            onWorkspaceCreated(data.data.id);
            onNext();
        } catch {
            setError('Something went wrong. Please try again.');
        } finally {
            setIsLoading(false);
        }
    };

    return (
        <div className="space-y-7">
            <div className="text-center space-y-3">
                <div className="mx-auto w-16 h-16 rounded-full bg-primary/10 flex items-center justify-center mb-3">
                    <Building2 className="h-8 w-8 text-primary" />
                </div>
                <h2 className="text-2xl font-bold tracking-tight">Create your workspace</h2>
                <p className="text-base text-muted-foreground">
                    Workspaces organize your projects and team members.
                </p>
            </div>

            <form onSubmit={handleSubmit} className="space-y-5">
                <div className="space-y-2">
                    <Label htmlFor="ws-name" className="text-sm font-medium">
                        Workspace Name
                    </Label>
                    <Input
                        id="ws-name"
                        placeholder="e.g., My Studio"
                        value={formData.name}
                        onChange={(e) => setFormData({ ...formData, name: e.target.value })}
                        required
                        disabled={isLoading}
                        className="h-11"
                    />
                </div>
                <div className="space-y-2">
                    <Label htmlFor="ws-desc" className="text-sm font-medium">
                        Description <span className="text-muted-foreground font-normal">(optional)</span>
                    </Label>
                    <Textarea
                        id="ws-desc"
                        placeholder="What is this workspace for?"
                        value={formData.description}
                        onChange={(e) => setFormData({ ...formData, description: e.target.value })}
                        rows={3}
                        disabled={isLoading}
                        className="resize-none"
                    />
                </div>

                {error && (
                    <div className="flex items-center gap-2 rounded-md bg-destructive/10 p-3 text-sm text-destructive">
                        <AlertCircle className="h-4 w-4 shrink-0" />
                        {error}
                    </div>
                )}

                <div className="flex flex-col gap-2 pt-1">
                    <Button type="submit" className="w-full h-11" disabled={isLoading || !formData.name.trim()}>
                        {isLoading ? (
                            <>
                                <Loader2 className="h-4 w-4 mr-2 animate-spin" />
                                Creating...
                            </>
                        ) : (
                            'Create Workspace'
                        )}
                    </Button>
                    <Button type="button" variant="ghost" onClick={onNext} disabled={isLoading} className="w-full text-muted-foreground">
                        Skip this step
                    </Button>
                </div>
            </form>
        </div>
    );
}

// ─── Step 3: Create Project ────────────────────────────────────────────────────

function StepProject({
    workspaceId,
    onNext,
    onProjectCreated,
}: {
    workspaceId: string | null;
    onNext: () => void;
    onProjectCreated: (id: string) => void;
}) {
    const [isLoading, setIsLoading] = useState(false);
    const [error, setError] = useState('');
    const [formData, setFormData] = useState({
        name: '',
        description: '',
        visibility: 'PRIVATE' as Visibility,
    });

    const handleSubmit = async (e: React.FormEvent) => {
        e.preventDefault();
        if (!workspaceId) return;
        setIsLoading(true);
        setError('');
        try {
            const res = await fetch('/api/projects', {
                method: 'POST',
                headers: { 'Content-Type': 'application/json' },
                body: JSON.stringify({ ...formData, workspaceId }),
            });
            const data = await res.json();
            if (!res.ok) {
                setError(data.error || 'Failed to create project');
                return;
            }
            onProjectCreated(data.data.id);
            onNext();
        } catch {
            setError('Something went wrong. Please try again.');
        } finally {
            setIsLoading(false);
        }
    };

    return (
        <div className="space-y-7">
            <div className="text-center space-y-3">
                <div className="mx-auto w-16 h-16 rounded-full bg-primary/10 flex items-center justify-center mb-3">
                    <FolderPlus className="h-8 w-8 text-primary" />
                </div>
                <h2 className="text-2xl font-bold tracking-tight">Create your first project</h2>
                <p className="text-base text-muted-foreground">
                    Projects hold your videos and collected feedback.
                </p>
            </div>

            {!workspaceId ? (
                <div className="space-y-4">
                    <div className="flex items-start gap-3 rounded-lg border border-dashed p-4 text-sm text-muted-foreground">
                        <Info className="h-4 w-4 shrink-0 mt-0.5" />
                        <span>You skipped workspace creation. Projects require a workspace — you can create both from the dashboard later.</span>
                    </div>
                    <Button onClick={onNext} className="w-full h-11">
                        Continue
                        <ChevronRight className="h-4 w-4 ml-1" />
                    </Button>
                </div>
            ) : (
                <form onSubmit={handleSubmit} className="space-y-5">
                    <div className="space-y-2">
                        <Label htmlFor="proj-name" className="text-sm font-medium">
                            Project Name
                        </Label>
                        <Input
                            id="proj-name"
                            placeholder="e.g., Product Demo Q1"
                            value={formData.name}
                            onChange={(e) => setFormData({ ...formData, name: e.target.value })}
                            required
                            disabled={isLoading}
                            className="h-11"
                        />
                    </div>
                    <div className="space-y-2">
                        <Label htmlFor="proj-desc" className="text-sm font-medium">
                            Description <span className="text-muted-foreground font-normal">(optional)</span>
                        </Label>
                        <Textarea
                            id="proj-desc"
                            placeholder="Brief description of what this project is about..."
                            value={formData.description}
                            onChange={(e) => setFormData({ ...formData, description: e.target.value })}
                            rows={3}
                            disabled={isLoading}
                            className="resize-none"
                        />
                    </div>

                    <div className="space-y-2">
                        <Label className="text-sm font-medium">Who can access?</Label>
                        <div className="grid gap-2.5">
                            {visibilityOptions.map((option) => (
                                <button
                                    key={option.value}
                                    type="button"
                                    onClick={() => setFormData({ ...formData, visibility: option.value })}
                                    disabled={isLoading}
                                    className={cn(
                                        'w-full flex items-center gap-4 p-4 rounded-xl border-2 text-left transition-all',
                                        formData.visibility === option.value
                                            ? 'border-primary bg-primary/5 ring-1 ring-primary/20'
                                            : 'border-border hover:border-border/80 hover:bg-accent/50'
                                    )}
                                >
                                    <div className={cn(
                                        'shrink-0 w-10 h-10 rounded-lg flex items-center justify-center',
                                        formData.visibility === option.value
                                            ? 'bg-primary text-primary-foreground'
                                            : 'bg-muted text-muted-foreground'
                                    )}>
                                        {option.icon}
                                    </div>
                                    <div className="flex-1 min-w-0">
                                        <div className="font-medium">{option.label}</div>
                                        <div className="text-sm text-muted-foreground">{option.description}</div>
                                    </div>
                                    <div className={cn(
                                        'shrink-0 w-5 h-5 rounded-full border-2 flex items-center justify-center',
                                        formData.visibility === option.value ? 'border-primary bg-primary' : 'border-muted-foreground/30'
                                    )}>
                                        {formData.visibility === option.value && (
                                            <div className="w-2 h-2 rounded-full bg-primary-foreground" />
                                        )}
                                    </div>
                                </button>
                            ))}
                        </div>
                    </div>

                    {error && (
                        <div className="flex items-center gap-2 rounded-md bg-destructive/10 p-3 text-sm text-destructive">
                            <AlertCircle className="h-4 w-4 shrink-0" />
                            {error}
                        </div>
                    )}

                    <div className="flex flex-col gap-2 pt-1">
                        <Button type="submit" className="w-full h-11" disabled={isLoading || !formData.name.trim()}>
                            {isLoading ? (
                                <>
                                    <Loader2 className="h-4 w-4 mr-2 animate-spin" />
                                    Creating...
                                </>
                            ) : (
                                'Create Project'
                            )}
                        </Button>
                        <Button type="button" variant="ghost" onClick={onNext} disabled={isLoading} className="w-full text-muted-foreground">
                            Skip this step
                        </Button>
                    </div>
                </form>
            )}
        </div>
    );
}

// ─── Step 4: Add First Video (informational) ───────────────────────────────────

function StepVideo({ onNext }: { onNext: () => void }) {
    return (
        <div className="space-y-7">
            <div className="text-center space-y-3">
                <div className="mx-auto w-16 h-16 rounded-full bg-primary/10 flex items-center justify-center mb-3">
                    <PlayCircle className="h-8 w-8 text-primary" />
                </div>
                <h2 className="text-2xl font-bold tracking-tight">Adding videos</h2>
                <p className="text-base text-muted-foreground">
                    OpenFrame supports two ways to add video content to your projects.
                </p>
            </div>

            <div className="grid gap-4">
                <div className="rounded-xl border p-5 space-y-2">
                    <div className="flex items-center gap-2.5 font-semibold">
                        <Youtube className="h-5 w-5 text-red-500" />
                        YouTube link
                    </div>
                    <p className="text-sm text-muted-foreground">
                        Paste a link to any YouTube video. OpenFrame will pull in the title, thumbnail, and duration automatically — no file upload needed.
                    </p>
                </div>
                <div className="rounded-xl border p-5 space-y-2">
                    <div className="flex items-center gap-2.5 font-semibold">
                        <Upload className="h-5 w-5 text-primary" />
                        Direct upload
                    </div>
                    <p className="text-sm text-muted-foreground">
                        Upload video files directly from your device. Files are processed and delivered via CDN for fast, reliable playback worldwide.
                    </p>
                </div>
            </div>

            <Button onClick={onNext} className="w-full h-11">
                Got it, continue
                <ChevronRight className="h-4 w-4 ml-1" />
            </Button>
        </div>
    );
}

// ─── Step 5: Notification Preferences ─────────────────────────────────────────

function StepNotifications({ onFinish }: { onFinish: () => Promise<void> }) {
    const [isSaving, setIsSaving] = useState(false);
    const [emailEnabled, setEmailEnabled] = useState(false);
    const [events, setEvents] = useState({
        onNewVideo: true,
        onNewComment: true,
        onNewReply: true,
    });

    const handleSave = async () => {
        setIsSaving(true);
        try {
            await fetch('/api/settings/notifications', {
                method: 'PUT',
                headers: { 'Content-Type': 'application/json' },
                body: JSON.stringify({
                    emailEnabled,
                    telegramEnabled: false,
                    telegramBotToken: null,
                    telegramChatId: null,
                    onNewVideo: events.onNewVideo,
                    onNewVersion: true,
                    onNewComment: events.onNewComment,
                    onNewReply: events.onNewReply,
                    onApprovalEvents: true,
                    timezone: Intl.DateTimeFormat().resolvedOptions().timeZone || 'UTC',
                }),
            });
        } catch {
            // best-effort; don't block finishing
        }
        await onFinish();
    };

    return (
        <div className="space-y-7">
            <div className="text-center space-y-3">
                <div className="mx-auto w-16 h-16 rounded-full bg-primary/10 flex items-center justify-center mb-3">
                    <Bell className="h-8 w-8 text-primary" />
                </div>
                <h2 className="text-2xl font-bold tracking-tight">Notification preferences</h2>
                <p className="text-base text-muted-foreground">
                    Choose when you want to be notified. Email and Telegram are both supported — you can configure Telegram anytime in Settings.
                </p>
            </div>

            <div className="space-y-4">
                <div className="space-y-2.5">
                    <div className="flex items-center gap-2 text-sm font-medium text-muted-foreground">
                        <Mail className="h-4 w-4" />
                        Channels
                    </div>
                    <ToggleButton
                        enabled={emailEnabled}
                        onToggle={() => setEmailEnabled((v) => !v)}
                        label="Email notifications"
                        description="Receive emails to your account address"
                    />
                </div>

                <div className="space-y-2.5">
                    <div className="flex items-center gap-2 text-sm font-medium text-muted-foreground">
                        <Bell className="h-4 w-4" />
                        Events
                    </div>
                    <ToggleButton
                        enabled={events.onNewVideo}
                        onToggle={() => setEvents((e) => ({ ...e, onNewVideo: !e.onNewVideo }))}
                        label="New Video Added"
                        description="When a new video is added to one of your projects"
                    />
                    <ToggleButton
                        enabled={events.onNewComment}
                        onToggle={() => setEvents((e) => ({ ...e, onNewComment: !e.onNewComment }))}
                        label="New Comment"
                        description="When someone leaves a comment on your videos"
                    />
                    <ToggleButton
                        enabled={events.onNewReply}
                        onToggle={() => setEvents((e) => ({ ...e, onNewReply: !e.onNewReply }))}
                        label="New Reply"
                        description="When someone replies to a comment thread"
                    />
                </div>
            </div>

            <div className="flex flex-col gap-2 pt-1">
                <Button onClick={handleSave} className="w-full h-11" disabled={isSaving}>
                    {isSaving ? (
                        <>
                            <Loader2 className="h-4 w-4 mr-2 animate-spin" />
                            Saving...
                        </>
                    ) : (
                        'Save & finish'
                    )}
                </Button>
                <Button type="button" variant="ghost" onClick={onFinish} disabled={isSaving} className="w-full text-muted-foreground">
                    Skip
                </Button>
            </div>
        </div>
    );
}

// ─── Wizard Shell ──────────────────────────────────────────────────────────────

export function OnboardingWizard({ userName }: { userName: string }) {
    const router = useRouter();
    const [currentStep, setCurrentStep] = useState(1);
    const [createdWorkspaceId, setCreatedWorkspaceId] = useState<string | null>(null);
    const [isCompleting, setIsCompleting] = useState(false);

    const goNext = () => setCurrentStep((s) => Math.min(s + 1, TOTAL_STEPS));

    const completeOnboarding = async () => {
        setIsCompleting(true);
        try {
            const res = await fetch('/api/onboarding/complete', { method: 'POST' });
            if (!res.ok) {
                toast.error('Failed to complete setup. Please try again.');
                setIsCompleting(false);
                return;
            }
        } catch {
            toast.error('Something went wrong. Please try again.');
            setIsCompleting(false);
            return;
        }
        router.push('/dashboard');
    };

    return (
        <div className="w-full max-w-2xl">
            {/* Top bar */}
            <div className="flex items-center justify-between mb-8">
                {/* Step dots */}
                <div className="flex items-center gap-2.5">
                    {Array.from({ length: TOTAL_STEPS }, (_, i) => i + 1).map((step) => (
                        <div
                            key={step}
                            className={cn(
                                'rounded-full transition-all',
                                step === currentStep
                                    ? 'w-7 h-3 bg-primary'
                                    : step < currentStep
                                    ? 'w-3 h-3 bg-primary/40'
                                    : 'w-3 h-3 bg-muted'
                            )}
                        />
                    ))}
                </div>

                {/* Skip button */}
                {currentStep > 1 && (
                    <Button
                        variant="ghost"
                        size="sm"
                        onClick={completeOnboarding}
                        disabled={isCompleting}
                        className="text-muted-foreground text-sm"
                    >
                        {isCompleting ? <Loader2 className="h-3 w-3 animate-spin mr-1" /> : null}
                        Skip setup
                    </Button>
                )}
            </div>

            {/* Step content */}
            <Card className="border-border/50 shadow-lg">
                <CardContent className="pt-10 pb-10 px-10">
                    {currentStep === 1 && (
                        <StepWelcome userName={userName} onNext={goNext} />
                    )}
                    {currentStep === 2 && (
                        <StepWorkspace onNext={goNext} onWorkspaceCreated={setCreatedWorkspaceId} />
                    )}
                    {currentStep === 3 && (
                        <StepProject workspaceId={createdWorkspaceId} onNext={goNext} onProjectCreated={() => {}} />
                    )}
                    {currentStep === 4 && (
                        <StepVideo onNext={goNext} />
                    )}
                    {currentStep === 5 && (
                        <StepNotifications onFinish={completeOnboarding} />
                    )}
                </CardContent>
            </Card>

            {/* Step label */}
            <p className="text-center text-sm text-muted-foreground mt-5">
                Step {currentStep} of {TOTAL_STEPS}
            </p>
        </div>
    );
}