using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Text.Json.Serialization;
using System.Threading.Tasks;

namespace wp2ghost
{
    public class IdsResponse
    {
        [JsonPropertyName("count")] public int Count { get; set; }
        [JsonPropertyName("post_type")] public string? PostType { get; set; }
        [JsonPropertyName("ids")] public List<int>? Ids { get; set; }
    }

    public class WpPostResponse
    {
        [JsonPropertyName("id")] public int Id { get; set; }
        [JsonPropertyName("title")] public string? Title { get; set; }
        [JsonPropertyName("slug")] public string? Slug { get; set; }
        // Veröffentlichungsdatum in der Ortszeit des Blogs (ohne Zeitzone)
        [JsonPropertyName("date")] public string? Date { get; set; }
        // Dasselbe in UTC — ab Plugin-Version mit date_gmt
        [JsonPropertyName("date_gmt")] public string? DateGmt { get; set; }
        [JsonPropertyName("content")] public string? Content { get; set; }
        [JsonPropertyName("excerpt")] public string? Excerpt { get; set; }
        [JsonPropertyName("featured_image")] public string? FeaturedImage { get; set; }
        [JsonPropertyName("categories")] public List<WpCategory>? Categories { get; set; } = new();
        [JsonPropertyName("tags")] public List<WpCategory>? Tags { get; set; } = new();
        [JsonPropertyName("keywords")] public string? Keywords { get; set; }
        [JsonPropertyName("comments")] public List<WpComment>? Comments { get; set; } = new();
        [JsonPropertyName("media_files")] public List<string>? MediaFiles { get; set; } = new();
    }

    public class WpCategory
    {
        [JsonPropertyName("id")] public int Id { get; set; }
        [JsonPropertyName("name")] public string? Name { get; set; }
        [JsonPropertyName("slug")] public string? Slug { get; set; }
    }

    // Datumsangaben für Ghost: immer UTC im Format 2022-11-19T09:30:00.000Z
    public static class DateHelper
    {
        private const string GhostFormat = "yyyy-MM-dd'T'HH:mm:ss.000'Z'";

        /// <summary>
        /// Wandelt ein Datum in UTC um. Ein Datum ohne Zeitzone (so liefert es WordPress) wird
        /// als Ortszeit dieses Rechners gedeutet. Liefert null, wenn es nicht lesbar ist.
        /// </summary>
        public static string? ToGhostUtc(string? date) => Convert(date, System.Globalization.DateTimeStyles.AssumeLocal);

        /// <summary>Wie ToGhostUtc, aber ein Datum ohne Zeitzone gilt als UTC (WordPress "date_gmt").</summary>
        public static string? FromGmt(string? date) => Convert(date, System.Globalization.DateTimeStyles.AssumeUniversal);

        private static string? Convert(string? date, System.Globalization.DateTimeStyles assume)
        {
            if (string.IsNullOrWhiteSpace(date)) return null;
            if (!DateTimeOffset.TryParse(date, System.Globalization.CultureInfo.InvariantCulture, assume, out var parsed)) return null;
            if (parsed.Year < 1990) return null; // WordPress-Platzhalter 0000-00-00
            return parsed.UtcDateTime.ToString(GhostFormat, System.Globalization.CultureInfo.InvariantCulture);
        }
    }

    // Kategorien, die nie nach Ghost übernommen werden
    public static class CategoryRules
    {
        private static readonly string[] IgnoredNames = { "Allgemein" };

        public static bool IsIgnored(string? name) =>
            IgnoredNames.Contains(System.Net.WebUtility.HtmlDecode(name ?? "").Trim(), StringComparer.OrdinalIgnoreCase);

        public static bool IsIgnored(WpCategory category) => IsIgnored(category.Name) || IsIgnored(category.Slug);
    }

    public class WpComment
    {
        [JsonPropertyName("id")] public int Id { get; set; }
        [JsonPropertyName("author_name")] public string? AuthorName { get; set; }
        [JsonPropertyName("author_email")] public string? AuthorEmail { get; set; }
        [JsonPropertyName("author_url")] public string? AuthorUrl { get; set; }
        [JsonPropertyName("content")] public string? Content { get; set; }
        [JsonPropertyName("date")] public string? Date { get; set; }
        // Ab Plugin-Version mit Kommentar-Typ: "comment", "pingback", "like", "repost" ...
        [JsonPropertyName("type")] public string? Type { get; set; }
        [JsonPropertyName("parent")] public int Parent { get; set; }
    }
}