"use client";

import IconTrashLines from "@/components/icon/icon-trash-lines";
import dynamic from "next/dynamic";
import React, { useMemo, useState, useEffect } from "react";
import "react-quill/dist/quill.snow.css";
import axios from "axios";
import Cookies from "universal-cookie";
import { useRouter, useParams } from "next/navigation";
import { showMessage } from "@/utils/CommonFunction.utils";
import { buildApiUrl } from "@/utils/BaseUrl.utils";

const ReactQuill = dynamic(() => import("react-quill"), {
    ssr: false,
});

const formats = [
    "header",
    "bold",
    "italic",
    "underline",
    "strike",
    "blockquote",
    "code-block",
    "list",
    "bullet",
    "align",
    "link",
    "image",
    "video",
];

const EditPostForm = () => {
    const router = useRouter();
    const params = useParams();
    const id = params.id;
    
    const [loading, setLoading] = useState(true);
    const [existingImage, setExistingImage] = useState<string>("");
    
    const [formData, setFormData] = useState({
        title: "",
        slug: "",
        coverImage: null as File | null,
        description: "",
        date: "",
        author: "",
    });

    useEffect(() => {
        const fetchBlog = async () => {
            try {
                const res = await axios.get(buildApiUrl(`blogs/${id}`));
                if (res.data && res.data.success) {
                    const blog = res.data.data;
                    setFormData({
                        title: blog.title || "",
                        slug: blog.slug || "",
                        coverImage: null,
                        description: blog.description || "",
                        date: blog.date || "",
                        author: blog.author || "",
                    });
                    if (blog.image) {
                        setExistingImage(blog.image);
                    }
                }
            } catch (error) {
                console.error("Error fetching blog details:", error);
                showMessage("Failed to load blog data", "error");
            } finally {
                setLoading(false);
            }
        };

        if (id) {
            fetchBlog();
        }
    }, [id]);

    const modules = useMemo(
        () => ({
            toolbar: {
                container: [
                    [{ header: [1, 2, 3, false] }],
                    ["bold", "italic", "underline", "strike"],
                    [{ list: "ordered" }, { list: "bullet" }],
                    ["blockquote", "code-block"],
                    [{ align: [] }],
                    ["link", "image", "video"],
                    ["clean"],
                ],
                handlers: {
                    image: function (this: any) {
                        const input = document.createElement("input");
                        input.setAttribute("type", "file");
                        input.setAttribute("accept", "image/*");
                        input.click();

                        input.onchange = async () => {
                            const file = input.files?.[0];

                            if (file) {
                                const reader = new FileReader();

                                reader.onload = () => {
                                    const quill = this.quill;
                                    const range = quill.getSelection(true);

                                    quill.insertEmbed(
                                        range.index,
                                        "image",
                                        reader.result
                                    );
                                };

                                reader.readAsDataURL(file);
                            }
                        };
                    },
                },
            },
        }),
        []
    );

    const handleChange = (e: React.ChangeEvent<HTMLInputElement>) => {
        const { name, value } = e.target;

        setFormData((prev) => ({
            ...prev,
            [name]: value,
        }));
    };

    const handleImageChange = (e: React.ChangeEvent<HTMLInputElement>) => {
        const file = e.target.files?.[0] || null;

        setFormData((prev) => ({
            ...prev,
            coverImage: file,
        }));
        setExistingImage(""); // Clear existing preview if new file selected
    };

    const handleRemoveImage = () => {
        setFormData((prev) => ({
            ...prev,
            coverImage: null,
        }));
        setExistingImage(""); // User wants to completely remove image
    };

    const handleDescriptionChange = (value: string) => {
        setFormData((prev) => ({
            ...prev,
            description: value,
        }));
    };

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

        if (!formData.title.trim()) {
            showMessage("Title is required", "error");
            return;
        }

        try {
            const cookies = new Cookies();
            const token = cookies.get('token');
            if (!token) {
                showMessage('Access denied. Please sign in first.', 'error');
                router.push('/login');
                return;
            }

            let coverImageUrl = existingImage; // Use existing image unless new one uploaded or removed

            if (formData.coverImage) {
                const data = new FormData();
                data.append("file", formData.coverImage);

                const imageUpload = await axios.post(buildApiUrl('upload/single'), data, {
                    headers: {
                        "Content-Type": "multipart/form-data",
                        Authorization: `Bearer ${token}`,
                    },
                });

                if (imageUpload.data && imageUpload.data.success) {
                    coverImageUrl = imageUpload.data.data.fullUrl;
                }
            }

            // Generate clean slug from title if not specified
            const cleanSlug = formData.slug.trim() 
                ? formData.slug.trim().toLowerCase().replace(/\s+/g, '-').replace(/[^\w\-]+/g, '')
                : formData.title.trim().toLowerCase().replace(/\s+/g, '-').replace(/[^\w\-]+/g, '');

            const updateData = {
                title: formData.title,
                slug: cleanSlug,
                image: coverImageUrl,
                description: formData.description,
                date: formData.date,
                author: formData.author,
            };

            const res = await axios.put(buildApiUrl(`blogs/${id}`), updateData, {
                headers: {
                    Authorization: `Bearer ${token}`,
                },
            });

            console.log("Update blog response:", res.data);
            showMessage("Blog Updated Successfully", "success");
            router.push("/blog");
        } catch (error: any) {
            console.error("Error updating blog:", error);
            showMessage(error?.response?.data?.message || "Error updating blog", "error");
        }
    };

    if (loading) {
        return <div className="text-center p-10">Loading blog details...</div>;
    }

    return (
        <form
            onSubmit={handleSubmit}
            className="space-y-5 max-w-4xl mx-auto p-6 bg-white rounded shadow-md mt-10"
        >
            <h2 className="text-xl font-bold mb-4">Edit Blog</h2>

            <div>
                <label className="block font-medium mb-1">Blog Title</label>
                <input
                    type="text"
                    name="title"
                    value={formData.title}
                    onChange={handleChange}
                    placeholder="Enter blog title"
                    className="w-full border rounded-md px-3 py-2 focus:ring-2 focus:ring-blue-500 outline-none"
                />
            </div>

            <div>
                <label className="block font-medium mb-1">Slug</label>
                <input
                    type="text"
                    name="slug"
                    value={formData.slug}
                    onChange={handleChange}
                    placeholder="Enter slug"
                    className="w-full border rounded-md px-3 py-2 focus:ring-2 focus:ring-green-500 outline-none"
                />
            </div>

            <div>
                <label className="block font-medium mb-1">Date</label>
                <input
                    type="text"
                    name="date"
                    value={formData.date}
                    onChange={handleChange}
                    placeholder="e.g. 12 Aug 2026"
                    className="w-full border rounded-md px-3 py-2 focus:ring-2 focus:ring-blue-500 outline-none"
                />
            </div>

            <div>
                <label className="block font-medium mb-1">Author</label>
                <input
                    type="text"
                    name="author"
                    value={formData.author}
                    onChange={handleChange}
                    placeholder="e.g. Gisselle"
                    className="w-full border rounded-md px-3 py-2 focus:ring-2 focus:ring-purple-500 outline-none"
                />
            </div>

            <div>
                <label className="block font-medium mb-1">Cover Image</label>
                <input
                    type="file"
                    accept="image/*"
                    onChange={handleImageChange}
                    className="w-full border rounded-md px-3 py-2 focus:ring-2 focus:ring-blue-500 outline-none"
                />
            </div>

            {(formData.coverImage || existingImage) && (
                <div className="mt-3">
                    <p className="text-sm font-medium">Preview:</p>
                    <div className="relative inline-block mt-2">
                        <img
                            src={formData.coverImage ? URL.createObjectURL(formData.coverImage) : existingImage}
                            alt="Selected"
                            className="w-48 h-32 object-cover rounded border"
                        />
                        <button
                            type="button"
                            onClick={handleRemoveImage}
                            className="absolute top-1 right-1 bg-red-600 text-white text-xs px-2 py-1 rounded hover:bg-red-700"
                        >
                            <IconTrashLines className="shrink-0" />
                        </button>
                    </div>
                </div>
            )}

            <div className="mb-5">
                <ReactQuill
                    value={formData.description}
                    onChange={handleDescriptionChange}
                    modules={modules}
                    formats={formats}
                    placeholder="Write your description..."
                    className="bg-white text-black rounded-md"
                />
            </div>

            <button
                type="submit"
                className="bg-blue-600 text-white px-6 py-2 mt-5 rounded-md hover:bg-blue-700 transition"
            >
                Update Blog
            </button>
        </form>
    );
};

export default EditPostForm;