using Microsoft.AspNetCore.Mvc;
using Microsoft.AspNetCore.Mvc.RazorPages;
using Microsoft.EntityFrameworkCore;
using System.ComponentModel.DataAnnotations;
using DrSousan.Api.Data;
using DrSousan.Api.Models;

namespace DrSousan.Api.Pages.Blog;

public class PostModel : PageModel
{
    private readonly AppDbContext _db;

    public PostModel(AppDbContext db) => _db = db;

    public BlogPost?      Post     { get; private set; }
    public List<CommentVm> Comments { get; private set; } = new();
    public bool           CommentSent { get; private set; } = false;
    // (question, answer) pairs extracted from the post body for FAQPage JSON-LD
    public List<(string Q, string A)> Faqs { get; private set; } = new();

    // Comment form binding
    [BindProperty]
    [Required(ErrorMessage = "نام الزامی است.")]
    [MaxLength(100)]
    public string CommentAuthor { get; set; } = "";

    [BindProperty]
    [MaxLength(200)]
    [EmailAddress]
    public string CommentEmail { get; set; } = "";

    [BindProperty]
    [Required(ErrorMessage = "متن نظر الزامی است.")]
    public string CommentBody { get; set; } = "";

    public async Task<IActionResult> OnGetAsync(string slug)
    {
        var post = await _db.BlogPosts
            .Include(p => p.Category)
            .FirstOrDefaultAsync(p => p.Slug == slug && p.IsPublished);

        if (post is null) return NotFound();

        // Increment view count
        post.ViewCount++;
        await _db.SaveChangesAsync();

        Post = post;
        Faqs = ExtractFaqs(post.Content);
        await LoadCommentsAsync(post.Id);
        await SetViewDataAsync(post);
        return Page();
    }

    // Pull FAQ pairs from the body: an <h3> whose text ends with the Persian
    // question mark (؟) followed by the next <p>. Drives FAQPage rich results.
    private static List<(string, string)> ExtractFaqs(string html)
    {
        var list = new List<(string, string)>();
        if (string.IsNullOrEmpty(html)) return list;
        var rx = new System.Text.RegularExpressions.Regex(
            @"<h3[^>]*>(?<q>.*?)</h3>\s*<p[^>]*>(?<a>.*?)</p>",
            System.Text.RegularExpressions.RegexOptions.Singleline |
            System.Text.RegularExpressions.RegexOptions.IgnoreCase);
        foreach (System.Text.RegularExpressions.Match m in rx.Matches(html))
        {
            var q = Strip(m.Groups["q"].Value);
            var a = Strip(m.Groups["a"].Value);
            if (q.EndsWith("؟") && a.Length > 0) list.Add((q, a));
        }
        return list;
    }

    private static string Strip(string s) =>
        System.Net.WebUtility.HtmlDecode(
            System.Text.RegularExpressions.Regex.Replace(s, "<[^>]*>", "")).Trim();

    public async Task<IActionResult> OnPostAsync(string slug)
    {
        var post = await _db.BlogPosts
            .Include(p => p.Category)
            .FirstOrDefaultAsync(p => p.Slug == slug && p.IsPublished);

        if (post is null) return NotFound();

        Post = post;
        await LoadCommentsAsync(post.Id);
        await SetViewDataAsync(post);

        if (!ModelState.IsValid) return Page();

        // Sanitise
        var body       = System.Text.RegularExpressions.Regex.Replace(CommentBody   ?? "", "<[^>]*>", "").Trim();
        var authorName = System.Text.RegularExpressions.Regex.Replace(CommentAuthor ?? "", "<[^>]*>", "").Trim();

        if (string.IsNullOrWhiteSpace(body) || string.IsNullOrWhiteSpace(authorName))
        {
            ModelState.AddModelError("", "نام و متن نظر الزامی است.");
            return Page();
        }

        _db.Comments.Add(new Comment
        {
            BlogPostId  = post.Id,
            AuthorName  = authorName,
            AuthorEmail = CommentEmail ?? "",
            Body        = body,
            IsApproved  = false,
            CreatedAt   = DateTime.UtcNow
        });
        await _db.SaveChangesAsync();

        CommentSent = true;
        // Clear form
        CommentAuthor = "";
        CommentEmail  = "";
        CommentBody   = "";
        ModelState.Clear();
        return Page();
    }

    private async Task LoadCommentsAsync(int postId)
    {
        var raw = await _db.Comments
            .Where(c => c.BlogPostId == postId && c.IsApproved && c.ParentId == null)
            .OrderBy(c => c.CreatedAt)
            .Select(c => new
            {
                c.Id, c.AuthorName, c.Body, c.CreatedAt, c.IsAdminReply,
                Replies = _db.Comments
                    .Where(r => r.ParentId == c.Id && r.IsApproved)
                    .OrderBy(r => r.CreatedAt)
                    .Select(r => new { r.Id, r.AuthorName, r.Body, r.CreatedAt, r.IsAdminReply })
                    .ToList()
            }).ToListAsync();

        Comments = raw.Select(c => new CommentVm
        {
            Id = c.Id, AuthorName = c.AuthorName, Body = c.Body,
            CreatedAt = c.CreatedAt, IsAdminReply = c.IsAdminReply,
            Replies = c.Replies.Select(r => new CommentVm
            {
                Id = r.Id, AuthorName = r.AuthorName, Body = r.Body,
                CreatedAt = r.CreatedAt, IsAdminReply = r.IsAdminReply
            }).ToList()
        }).ToList();
    }

    private async Task SetViewDataAsync(BlogPost post)
    {
        var metaTitle = string.IsNullOrEmpty(post.MetaTitle) ? post.Title : post.MetaTitle;
        var metaDesc  = string.IsNullOrEmpty(post.MetaDescription) ? post.Excerpt : post.MetaDescription;

        // Avoid duplicating the site name if MetaTitle already contains it
        var suffix    = " | دکتر سوسن آل‌طه";
        ViewData["Title"] = metaTitle.Contains("دکتر سوسن") ? metaTitle : metaTitle + suffix;
        ViewData["MetaDesc"]    = metaDesc;
        ViewData["Keywords"]    = post.Keywords;
        ViewData["OgImage"]     = string.IsNullOrEmpty(post.OgImage) ? post.FeaturedImage : post.OgImage;
        ViewData["ArticleType"] = post.ArticleType;
        ViewData["Slug"]        = post.Slug;

        var heroSettings = await _db.SiteSettings
            .Where(x => x.Section == "hero" && (x.Key == "name" || x.Key == "image" || x.Key == "tag"))
            .ToListAsync();
        ViewData["SiteName"]  = heroSettings.FirstOrDefault(x => x.Key == "name")?.Value  ?? "دکتر سوسن آل‌طه";
        ViewData["HeroImage"] = heroSettings.FirstOrDefault(x => x.Key == "image")?.Value ?? "";
        ViewData["HeroTag"]   = heroSettings.FirstOrDefault(x => x.Key == "tag")?.Value   ?? "پزشک عمومی و متخصص زیبایی پوست";
    }

    // View model for comments
    public class CommentVm
    {
        public int Id { get; set; }
        public string AuthorName { get; set; } = "";
        public string Body { get; set; } = "";
        public DateTime CreatedAt { get; set; }
        public bool IsAdminReply { get; set; }
        public List<CommentVm> Replies { get; set; } = new();
    }
}