"use client";

import { useState, useEffect } from 'react';
import { useRouter } from 'next/navigation';
import { useSession } from "next-auth/react";
import { useEditor, EditorContent } from '@tiptap/react';
import StarterKit from '@tiptap/starter-kit';
import LinkExtension from '@tiptap/extension-link';
import ImageExtension from '@tiptap/extension-image';
import { Button } from '@/components/ui/button';
import { Input } from '@/components/ui/input';
import { Label } from '@/components/ui/label';
import { Textarea } from '@/components/ui/textarea';
import { Select, SelectContent, SelectItem, SelectTrigger, SelectValue } from '@/components/ui/select';
import { Card, CardContent } from '@/components/ui/card';
import { Bold, Italic, List, ListOrdered, Link as LinkIcon, Image as ImageIcon, Loader2 } from 'lucide-react';

const API_URL = process.env.NEXT_PUBLIC_API_URL || 'http://localhost:5000/api';

interface BlogFormProps {
    initialData?: any;
    isEditing?: boolean;
}

export default function BlogForm({ initialData = null, isEditing = false }: BlogFormProps) {
    const router = useRouter();
    const { data: session } = useSession();
    const [isLoading, setIsLoading] = useState(false);

    // Form State
    const [title, setTitle] = useState(initialData?.title || '');
    const [slug, setSlug] = useState(initialData?.slug || '');
    const [excerpt, setExcerpt] = useState(initialData?.excerpt || '');
    const [featuredImage, setFeaturedImage] = useState(initialData?.featuredImage || '');
    const [status, setStatus] = useState(initialData?.status || 'DRAFT');
    const [publishedAt, setPublishedAt] = useState(initialData?.publishedAt ? new Date(initialData.publishedAt).toISOString().slice(0, 16) : '');
    const [tags, setTags] = useState(initialData?.tags ? JSON.parse(initialData.tags).join(', ') : '');

    const editor = useEditor({
        extensions: [
            StarterKit,
            LinkExtension.configure({ openOnClick: false }),
            ImageExtension.configure({ inline: true }),
        ],
        content: initialData?.content || '<p>Start writing your post here...</p>',
        immediatelyRender: false,
        editorProps: {
            attributes: {
                class: 'prose prose-sm sm:prose lg:prose-lg xl:prose-2xl mx-auto focus:outline-none min-h-[400px] p-4 border rounded-md max-w-none',
            },
        },
    });

    const setLink = () => {
        const previousUrl = editor?.getAttributes('link').href;
        const url = window.prompt('URL', previousUrl);
        if (url === null) return;
        if (url === '') {
            editor?.chain().focus().extendMarkRange('link').unsetLink().run();
            return;
        }
        editor?.chain().focus().extendMarkRange('link').setLink({ href: url }).run();
    };

    const addImage = () => {
        const url = window.prompt('Image URL');
        if (url) {
            editor?.chain().focus().setImage({ src: url }).run();
        }
    };

    const handleSubmit = async (e: React.FormEvent) => {
        e.preventDefault();
        setIsLoading(true);

        const content = editor?.getHTML();
        const tagsArray = tags.split(',').map((t: string) => t.trim()).filter(Boolean);

        const payload = {
            title,
            slug: slug || undefined,
            content,
            excerpt,
            featuredImage,
            status,
            publishedAt: publishedAt ? new Date(publishedAt).toISOString() : null,
            tags: JSON.stringify(tagsArray)
        };

        try {
            const url = isEditing && initialData?.id
                ? `${API_URL}/admin/blog/${initialData.id}`
                : `${API_URL}/admin/blog`;

            const method = isEditing ? 'PUT' : 'POST';

            const res = await fetch(url, {
                method,
                headers: {
                    'Content-Type': 'application/json',
                    'Authorization': `Bearer ${session?.user?.id}`
                },
                body: JSON.stringify(payload)
            });

            if (res.ok) {
                router.push('/admin/blog');
                router.refresh();
            } else {
                const data = await res.json();
                alert(`Error: ${data.error || 'Failed to save post'}`);
            }
        } catch (error) {
            console.error("Save error:", error);
            alert("An unexpected error occurred while saving.");
        } finally {
            setIsLoading(false);
        }
    };

    return (
        <form onSubmit={handleSubmit} className="space-y-8">
            <div className="flex flex-col md:flex-row justify-between items-start md:items-center gap-4">
                <h2 className="text-3xl font-bold tracking-tight">
                    {isEditing ? 'Edit Article' : 'New Article'}
                </h2>
                <div className="flex gap-2 w-full md:w-auto">
                    <Button variant="outline" type="button" onClick={() => router.push('/admin/blog')}>
                        Cancel
                    </Button>
                    <Button type="submit" disabled={isLoading || !title || !editor?.getHTML()}>
                        {isLoading ? <Loader2 className="mr-2 h-4 w-4 animate-spin" /> : null}
                        {isEditing ? 'Save Changes' : 'Create Post'}
                    </Button>
                </div>
            </div>

            <div className="grid grid-cols-1 lg:grid-cols-3 gap-8">
                {/* Main Content Area */}
                <div className="lg:col-span-2 space-y-6">
                    <Card>
                        <CardContent className="p-6 space-y-4">
                            <div className="space-y-2">
                                <Label htmlFor="title">Post Title *</Label>
                                <Input
                                    id="title"
                                    value={title}
                                    onChange={(e) => setTitle(e.target.value)}
                                    placeholder="Enter an engaging title..."
                                    required
                                    className="text-lg font-medium"
                                />
                            </div>

                            <div className="space-y-2">
                                <Label>Content *</Label>
                                {editor && (
                                    <div className="border rounded-md overflow-hidden bg-background">
                                        {/* TipTap Toolbar */}
                                        <div className="flex flex-wrap items-center gap-1 p-1 border-b bg-muted/30">
                                            <Button type="button" variant="ghost" size="sm" onClick={() => editor.chain().focus().toggleBold().run()} className={editor.isActive('bold') ? 'bg-muted' : ''}>
                                                <Bold className="h-4 w-4" />
                                            </Button>
                                            <Button type="button" variant="ghost" size="sm" onClick={() => editor.chain().focus().toggleItalic().run()} className={editor.isActive('italic') ? 'bg-muted' : ''}>
                                                <Italic className="h-4 w-4" />
                                            </Button>
                                            <div className="w-px h-4 bg-border mx-1" />
                                            <Button type="button" variant="ghost" size="sm" onClick={() => editor.chain().focus().toggleHeading({ level: 2 }).run()} className={editor.isActive('heading', { level: 2 }) ? 'bg-muted' : ''}>
                                                H2
                                            </Button>
                                            <Button type="button" variant="ghost" size="sm" onClick={() => editor.chain().focus().toggleHeading({ level: 3 }).run()} className={editor.isActive('heading', { level: 3 }) ? 'bg-muted' : ''}>
                                                H3
                                            </Button>
                                            <div className="w-px h-4 bg-border mx-1" />
                                            <Button type="button" variant="ghost" size="sm" onClick={() => editor.chain().focus().toggleBulletList().run()} className={editor.isActive('bulletList') ? 'bg-muted' : ''}>
                                                <List className="h-4 w-4" />
                                            </Button>
                                            <Button type="button" variant="ghost" size="sm" onClick={() => editor.chain().focus().toggleOrderedList().run()} className={editor.isActive('orderedList') ? 'bg-muted' : ''}>
                                                <ListOrdered className="h-4 w-4" />
                                            </Button>
                                            <div className="w-px h-4 bg-border mx-1" />
                                            <Button type="button" variant="ghost" size="sm" onClick={setLink} className={editor.isActive('link') ? 'bg-muted' : ''}>
                                                <LinkIcon className="h-4 w-4" />
                                            </Button>
                                            <Button type="button" variant="ghost" size="sm" onClick={addImage}>
                                                <ImageIcon className="h-4 w-4" />
                                            </Button>
                                        </div>
                                        {/* TipTap Editor */}
                                        <EditorContent editor={editor} />
                                    </div>
                                )}
                            </div>

                            <div className="space-y-2">
                                <Label htmlFor="excerpt">Excerpt / Summary</Label>
                                <Textarea
                                    id="excerpt"
                                    value={excerpt}
                                    onChange={(e) => setExcerpt(e.target.value)}
                                    placeholder="Brief summary for search engines and social sharing..."
                                    rows={3}
                                />
                            </div>
                        </CardContent>
                    </Card>
                </div>

                {/* Sidebar Metrics & Settings */}
                <div className="space-y-6">
                    <Card>
                        <CardContent className="p-6 space-y-4">
                            <div className="space-y-2">
                                <Label htmlFor="status">Publishing Status</Label>
                                <Select value={status} onValueChange={setStatus}>
                                    <SelectTrigger>
                                        <SelectValue placeholder="Select status" />
                                    </SelectTrigger>
                                    <SelectContent>
                                        <SelectItem value="DRAFT">Draft</SelectItem>
                                        <SelectItem value="PUBLISHED">Published</SelectItem>
                                        <SelectItem value="SCHEDULED">Scheduled</SelectItem>
                                    </SelectContent>
                                </Select>
                            </div>

                            <div className="space-y-2">
                                <Label htmlFor="publishedAt">Publish Date</Label>
                                <Input
                                    id="publishedAt"
                                    type="datetime-local"
                                    value={publishedAt}
                                    onChange={(e) => setPublishedAt(e.target.value)}
                                    disabled={status === 'DRAFT'}
                                />
                                {status === 'DRAFT' && <p className="text-xs text-muted-foreground">Date is disabled while in Draft status.</p>}
                            </div>

                            <div className="space-y-2 pt-4 border-t">
                                <Label htmlFor="slug">Custom URL Slug (Optional)</Label>
                                <Input
                                    id="slug"
                                    value={slug}
                                    onChange={(e) => setSlug(e.target.value)}
                                    placeholder="e.g. my-awesome-post"
                                />
                                <p className="text-xs text-muted-foreground">Leave blank to auto-generate from title.</p>
                            </div>

                            <div className="space-y-2 pt-4 border-t">
                                <Label htmlFor="featuredImage">Featured Image URL</Label>
                                <Input
                                    id="featuredImage"
                                    value={featuredImage}
                                    onChange={(e) => setFeaturedImage(e.target.value)}
                                    placeholder="https://..."
                                />
                                {featuredImage && (
                                    <div className="mt-2 text-xs text-muted-foreground overflow-hidden rounded-md h-32 bg-muted relative">
                                        {/* eslint-disable-next-line @next/next/no-img-element */}
                                        <img src={featuredImage} alt="Featured preview" className="object-cover w-full h-full" />
                                    </div>
                                )}
                            </div>

                            <div className="space-y-2 pt-4 border-t">
                                <Label htmlFor="tags">Tags (Comma separated)</Label>
                                <Input
                                    id="tags"
                                    value={tags}
                                    onChange={(e) => setTags(e.target.value)}
                                    placeholder="React, Design, Tech"
                                />
                            </div>
                        </CardContent>
                    </Card>
                </div>
            </div>
        </form>
    );
}