using System;
using System.Collections.Generic;
using System.Linq;

namespace Jellyfin.Plugin.Floatplane.Api.Models;

/// <summary>GET /api/v3/delivery/info response.</summary>
public class DeliveryInfoModel
{
    public List<DeliveryGroup> Groups { get; set; } = new();

    /// <summary>Flattens every usable variant with its absolute URL.</summary>
    public IEnumerable<ResolvedVariant> Resolve()
    {
        foreach (var group in Groups)
        {
            var groupOrigin = group.Origins.FirstOrDefault()?.Url;
            foreach (var v in group.Variants)
            {
                var origin = v.Origins?.FirstOrDefault()?.Url ?? groupOrigin;
                if (string.IsNullOrEmpty(v.Url))
                {
                    continue;
                }

                string url;
                if (IsHttpUrl(v.Url))
                {
                    url = v.Url;
                }
                else if (!string.IsNullOrEmpty(origin))
                {
                    url = origin.TrimEnd('/') + "/" + v.Url.TrimStart('/');
                }
                else
                {
                    continue;
                }

                yield return new ResolvedVariant(v, url);
            }
        }
    }

    /// <summary>
    /// True for http(s) URLs only. <c>Uri.TryCreate(…, UriKind.Absolute)</c> must not be used
    /// for this: on Linux a path like <c>/Videos/x.m3u8</c> parses as an absolute <c>file:///</c> URI.
    /// </summary>
    public static bool IsHttpUrl(string value)
        => value.StartsWith("http://", StringComparison.OrdinalIgnoreCase) || value.StartsWith("https://", StringComparison.OrdinalIgnoreCase);
}

public class DeliveryGroup
{
    public List<DeliveryOrigin> Origins { get; set; } = new();

    public List<DeliveryVariant> Variants { get; set; } = new();
}

public class DeliveryOrigin
{
    public string Url { get; set; } = string.Empty;

    public string? QueryUrl { get; set; }
}

public class DeliveryVariant
{
    /// <summary>e.g. "1080-avc1".</summary>
    public string Name { get; set; } = string.Empty;

    /// <summary>e.g. "1080p", "4K".</summary>
    public string? Label { get; set; }

    /// <summary>Relative (to origin) or absolute URL incl. signed token. Empty when denied.</summary>
    public string Url { get; set; } = string.Empty;

    public string? MimeType { get; set; }

    public long Order { get; set; }

    public bool Hidden { get; set; }

    public bool Enabled { get; set; } = true;

    public List<DeliveryOrigin>? Origins { get; set; }

    public VariantMeta? Meta { get; set; }

    public bool IsUsable => Enabled && !Hidden && !string.IsNullOrEmpty(Url);

    public int Height => Meta?.Video?.Height ?? ParseHeight(Name);

    public static int ParseHeight(string name)
    {
        var dash = name.IndexOf('-', StringComparison.Ordinal);
        var head = dash > 0 ? name[..dash] : name;
        return int.TryParse(head, out var h) ? h : 0;
    }
}

public class VariantMeta
{
    public VariantVideoMeta? Video { get; set; }

    public VariantAudioMeta? Audio { get; set; }

    public VariantCommonMeta? Common { get; set; }

    public VariantLiveMeta? Live { get; set; }
}

public class VariantVideoMeta
{
    public string? Codec { get; set; }

    public string? CodecSimple { get; set; }

    public BitrateMeta? Bitrate { get; set; }

    public int Width { get; set; }

    public int Height { get; set; }

    public bool IsHdr { get; set; }

    public double Fps { get; set; }

    public string? MimeType { get; set; }
}

public class VariantAudioMeta
{
    public string? Codec { get; set; }

    public BitrateMeta? Bitrate { get; set; }

    public int ChannelCount { get; set; }

    public int Samplerate { get; set; }

    public string? MimeType { get; set; }
}

public class BitrateMeta
{
    public long Average { get; set; }

    public long? Maximum { get; set; }
}

public class VariantCommonMeta
{
    public VariantAccess? Access { get; set; }
}

public class VariantAccess
{
    public string? DeniedReason { get; set; }

    public string? DeniedMessage { get; set; }
}

public class VariantLiveMeta
{
    public string? LowLatencyExtension { get; set; }
}

/// <summary>A delivery variant with its absolute URL.</summary>
public record ResolvedVariant(DeliveryVariant Variant, string Url)
{
    public string Name => Variant.Name;

    public int Height => Variant.Height;

    public bool IsUsable => Variant.IsUsable;
}