using System.Net;
using System.Text;
using System.Text.Json;
using System.Text.Json.Serialization;
using Npgsql;

namespace Yuanshen.SDK.Handlers;

public sealed class GachaLogRow
{
    [JsonPropertyName("gachaType")] public uint GachaType { get; set; }
    [JsonPropertyName("itemId")] public uint ItemId { get; set; }
    [JsonPropertyName("rankLevel")] public uint RankLevel { get; set; }
    [JsonPropertyName("name")] public string Name { get; set; } = string.Empty;
    [JsonPropertyName("kind")] public string Kind { get; set; } = string.Empty;
    [JsonPropertyName("time")] public long Time { get; set; }
}

public sealed class PlayerSnapshot
{
    [JsonPropertyName("gachaLog")] public List<GachaLogRow> GachaLog { get; set; } = new();
    [JsonPropertyName("gachaPity")] public Dictionary<string, uint> GachaPity { get; set; } = new();
    [JsonPropertyName("nickname")] public string Nickname { get; set; } = string.Empty;
}

public static class GachaHistoryHandler
{
    private const string SelectSql = "SELECT data FROM players ORDER BY updated_at DESC LIMIT 1";

    private static readonly JsonSerializerOptions Options = new()
    {
        PropertyNamingPolicy = JsonNamingPolicy.CamelCase
    };

    private static readonly Dictionary<uint, string> BannerNames = new()
    {
        [100] = "Novice",
        [200] = "Standard",
        [301] = "Character Event",
        [302] = "Weapon Event"
    };

    private static readonly string[] WeaponTypes =
        { "Weapon", "Sword", "Claymore", "Polearm", "Catalyst", "Bow" };

    private static string? _connectionString;

    public static void Use(string connectionString) => _connectionString = connectionString;

    public static async Task<IResult> OnHistory(HttpRequest request)
    {
        PlayerSnapshot snapshot;

        try
        {
            snapshot = await LoadAsync();
        }
        catch (Exception exception)
        {
            Log.Warn($"gacha history unavailable: {exception.Message}");
            return Html(Page("Wish History", $"<p class=\"empty\">Could not read the database.<br><span class=\"dim\">{WebUtility.HtmlEncode(exception.Message)}</span></p>"));
        }

        List<GachaLogRow> log = snapshot.GachaLog;

        if (log.Count == 0)
            return Html(Page("Wish History", "<p class=\"empty\">No wishes yet.<br><span class=\"dim\">Pull on a banner and it will show up here.</span></p>"));

        uint filter = request.Query.TryGetValue("banner", out Microsoft.Extensions.Primitives.StringValues raw)
                      && uint.TryParse(raw, out uint parsed)
            ? parsed
            : 0;

        List<GachaLogRow> shown = filter == 0 ? log : log.Where(entry => entry.GachaType == filter).ToList();
        shown = Enumerable.Reverse(shown).ToList();

        StringBuilder body = new();
        body.Append(Stats(shown, snapshot.GachaPity, filter));
        body.Append(Tabs(log, filter));

        if (shown.Count == 0)
        {
            body.Append("<p class=\"empty\">Nothing on this banner yet.</p>");
            return Html(Page("Wish History", body.ToString()));
        }

        body.Append("<div class=\"list\">");

        string lastDate = string.Empty;
        int index = shown.Count;

        foreach (GachaLogRow entry in shown)
        {
            DateTime when = DateTimeOffset.FromUnixTimeSeconds(entry.Time).LocalDateTime;
            string date = when.ToString("dd MMM yyyy");

            if (date != lastDate)
            {
                body.Append($"<div class=\"day\">{date}</div>");
                lastDate = date;
            }

            uint rank = Math.Clamp(entry.RankLevel, 3, 5);
            string label = WebUtility.HtmlEncode(Label(entry));
            string banner = WebUtility.HtmlEncode(BannerNames.GetValueOrDefault(entry.GachaType, $"Type {entry.GachaType}"));

            body.Append(
                $"<div class=\"row r{rank}\">"
                + Icon(entry)
                + $"<span class=\"pip\">{rank}★</span>"
                + $"<span class=\"name\">{label}</span>"
                + $"<span class=\"id\">{entry.ItemId}</span>"
                + $"<span class=\"banner\">{banner}</span>"
                + $"<span class=\"time\">{when:HH:mm}</span>"
                + $"<span class=\"num\">#{index--}</span>"
                + "</div>");
        }

        body.Append("</div>");
        return Html(Page("Wish History", body.ToString()));
    }

    private static uint WeaponSlot(GachaLogRow entry)
        => entry.ItemId >= 10000 ? entry.ItemId / 1000 % 10 : 0;

    private static string Icon(GachaLogRow entry)
    {
        string glyph = WeaponSlot(entry) switch
        {
            1 => "<path d='M6 26 L20 12 M18 10 l4 4 M22 6 l4 4 -4 4 -4 -4z' />",
            2 => "<path d='M7 25 l5-5 M11 19 l6-10 4 4 -10 6z M20 8 l4 4' />",
            3 => "<path d='M6 26 L24 8 M20 4 l8 0 0 8' />",
            4 => "<circle cx='16' cy='16' r='6' /><path d='M16 4 v4 M16 24 v4 M4 16 h4 M24 16 h4' />",
            5 => "<path d='M9 6 a14 14 0 0 1 0 20 M9 6 L26 16 9 26' />",
            _ => "<circle cx='16' cy='12' r='5' /><path d='M7 27 a9 9 0 0 1 18 0' />"
        };

        return $"<span class=\"ico\"><svg viewBox='0 0 32 32' fill='none' stroke='currentColor' "
               + $"stroke-width='2' stroke-linecap='round' stroke-linejoin='round'>{glyph}</svg></span>";
    }

    private static string Label(GachaLogRow entry)
    {
        if (!string.IsNullOrEmpty(entry.Name))
            return entry.Name;

        if (entry.ItemId >= 10000)
        {
            uint type = entry.ItemId / 1000 % 10;
            return type < WeaponTypes.Length ? WeaponTypes[type] : "Weapon";
        }

        return $"Character {entry.ItemId}";
    }

    private static string Stats(List<GachaLogRow> shown, Dictionary<string, uint> pity, uint filter)
    {
        int five = shown.Count(entry => entry.RankLevel >= 5);
        int four = shown.Count(entry => entry.RankLevel == 4);

        string pityChip = string.Empty;
        if (filter != 0 && pity.TryGetValue(filter.ToString(), out uint counter))
            pityChip = Chip("Pity", counter.ToString(), "c-pity");

        return "<div class=\"stats\">"
               + Chip("Wishes", shown.Count.ToString(), "c-all")
               + Chip("5★", five.ToString(), "c5")
               + Chip("4★", four.ToString(), "c4")
               + pityChip
               + "</div>";
    }

    private static string Chip(string label, string value, string cls)
        => $"<div class=\"chip {cls}\"><b>{value}</b><span>{WebUtility.HtmlEncode(label)}</span></div>";

    private static string Tabs(List<GachaLogRow> log, uint filter)
    {
        StringBuilder tabs = new("<div class=\"tabs\">");
        tabs.Append(Tab("All", 0, filter));

        foreach (uint type in log.Select(entry => entry.GachaType).Distinct().OrderBy(type => type))
            tabs.Append(Tab(BannerNames.GetValueOrDefault(type, $"Type {type}"), type, filter));

        tabs.Append("</div>");
        return tabs.ToString();
    }

    private static string Tab(string label, uint type, uint active)
        => $"<a class=\"tab{(type == active ? " on" : string.Empty)}\" href=\"?banner={type}\">{WebUtility.HtmlEncode(label)}</a>";

    private static async Task<PlayerSnapshot> LoadAsync()
    {
        if (string.IsNullOrEmpty(_connectionString))
            throw new InvalidOperationException("database connection string is not configured");

        await using NpgsqlConnection connection = new(_connectionString);
        await connection.OpenAsync();

        await using NpgsqlCommand command = new(SelectSql, connection);
        object? result = await command.ExecuteScalarAsync();

        if (result is not string json)
            return new PlayerSnapshot();

        return JsonSerializer.Deserialize<PlayerSnapshot>(json, Options) ?? new PlayerSnapshot();
    }

    private static IResult Html(string html) => TypedResults.Text(html, "text/html; charset=utf-8");

    private static string Page(string title, string body) => $$"""
        <!DOCTYPE html>
        <html><head><meta charset="utf-8"><title>{{title}}</title>
        <meta name="viewport" content="width=device-width,initial-scale=1">
        <style>
        *{box-sizing:border-box}
        body{background:#16101c;color:#ece4f5;font:17px/1.55 -apple-system,"Segoe UI",Roboto,sans-serif;margin:0;padding:34px 20px 64px}
        .wrap{max-width:1040px;margin:0 auto}
        h1{font-size:30px;margin:0 0 22px;background:linear-gradient(90deg,#a35cff,#e040fb);-webkit-background-clip:text;background-clip:text;color:transparent;display:inline-block}
        .stats{display:flex;gap:14px;margin-bottom:24px;flex-wrap:wrap}
        .chip{background:#221a2c;border:1px solid #322640;border-radius:14px;padding:13px 22px;min-width:112px}
        .chip b{display:block;font-size:30px;line-height:1.1}
        .chip span{font-size:13px;color:#8b7d9b;letter-spacing:.05em;text-transform:uppercase}
        .c5 b{color:#ffb34d}.c4 b{color:#c77dff}.c-pity b{color:#7ce8a4}.c-all b{color:#ece4f5}
        .tabs{display:flex;gap:9px;flex-wrap:wrap;margin-bottom:22px}
        .tab{padding:10px 20px;border-radius:999px;background:#221a2c;color:#a89bb8;text-decoration:none;font-size:16px;border:1px solid transparent}
        .tab.on{background:linear-gradient(90deg,#7b2ff7,#e040fb);color:#fff}
        .day{font-size:13px;color:#6b5e7a;letter-spacing:.1em;text-transform:uppercase;margin:26px 0 10px;padding-left:4px}
        .list{display:flex;flex-direction:column;gap:6px}
        .row{display:grid;grid-template-columns:52px 46px 1fr auto auto 64px 62px;align-items:center;gap:16px;
             padding:14px 18px;border-radius:13px;background:#1c1524;border-left:4px solid #2e2438}
        .ico{width:44px;height:44px;border-radius:12px;display:flex;align-items:center;justify-content:center;
             background:#2a2136;color:#8b7d9b;border:1px solid #35283f}
        .ico svg{width:26px;height:26px}
        .pip{font-size:16px;font-weight:600;color:#7d6f8d}
        .name{font-weight:600;font-size:19px;overflow:hidden;text-overflow:ellipsis;white-space:nowrap}
        .id{font-size:15px;color:#5f5470;font-variant-numeric:tabular-nums}
        .banner{font-size:16px;color:#8b7d9b;white-space:nowrap}
        .time{font-size:16px;color:#6b5e7a;font-variant-numeric:tabular-nums;text-align:right}
        .num{font-size:14px;color:#463c53;text-align:right;font-variant-numeric:tabular-nums}
        .r3{opacity:.78}
        .r4{border-left-color:#c77dff;background:#241b31}
        .r4 .pip,.r4 .name{color:#d9b0ff}
        .r4 .ico{background:#33234a;color:#d9b0ff;border-color:#4a3363}
        .r5{border-left-color:#ffb34d;background:#2c2219;box-shadow:0 0 0 1px #4a3a1e inset}
        .r5 .pip,.r5 .name{color:#ffc978}
        .r5 .ico{background:#463217;color:#ffc978;border-color:#6b4d21}
        .empty{color:#8b7d9b;background:#1c1524;border-radius:14px;padding:34px;text-align:center;font-size:18px}
        .dim{color:#6b5e7a;font-size:15px}
        </style></head>
        <body><div class="wrap"><h1>{{title}}</h1>{{body}}</div></body></html>
        """;
}