using System.Linq;
using System.Numerics;
using System.Threading.Tasks;
using Content.Client.Stylesheets;
using Content.Shared.CCVar;
using Robust.Client.AutoGenerated;
using Robust.Client.Credits;
using Robust.Client.UserInterface;
using Robust.Client.UserInterface.Controls;
using Robust.Client.UserInterface.CustomControls;
using Robust.Client.UserInterface.XAML;
using Robust.Shared.Configuration;
using Robust.Shared.ContentPack;
using Robust.Shared.Prototypes;
using Robust.Shared.Serialization.Manager;
using Robust.Shared.Serialization.Markdown;
using Robust.Shared.Serialization.Markdown.Mapping;
using Robust.Shared.Serialization.Markdown.Sequence;
using Robust.Shared.Utility;
using YamlDotNet.RepresentationModel;
using static Robust.Client.UserInterface.Controls.BoxContainer;

namespace Content.Client.Credits;

[GenerateTypedNameReferences]
public sealed partial class CreditsWindow : DefaultWindow
{
    [Dependency] private readonly IResourceManager _resourceManager = default!;
    [Dependency] private readonly IConfigurationManager _cfg = default!;
    [Dependency] private readonly ISerializationManager _serialization = default!;
    [Dependency] private readonly IPrototypeManager _protoManager = default!;
    [Dependency] private readonly ILocalizationManager _loc = default!;

    private static readonly Dictionary<string, int> PatronTierPriority = new()
    {
        ["Nuclear Operative"] = 1,
        ["Syndicate Agent"] = 2,
        ["Revolutionary"] = 3,
    };

    private readonly List<FormattedMessage> _attributions = [];
    private readonly ISawmill _sawmill = Logger.GetSawmill("Credits");

    private const int AttributionsSourcesPerPage = 50;

    public CreditsWindow()
    {
        IoCManager.InjectDependencies(this);
        RobustXamlLoader.Load(this);

        TabContainer.SetTabTitle(Ss14ContributorsTab, Loc.GetString("credits-window-ss14contributorslist-tab"));
        TabContainer.SetTabTitle(PatronsTab, Loc.GetString("credits-window-patrons-tab"));
        TabContainer.SetTabTitle(LicensesTab, Loc.GetString("credits-window-licenses-tab"));
        TabContainer.SetTabTitle(AttributionsTab, Loc.GetString("credits-window-attributions-tab"));

        _protoManager.PrototypesReloaded += _ =>
        {
            _attributions.Clear();
        };

        MasterTabContainer.OnTabChanged += OnTabChanged;

        PopulateContributors(Ss14ContributorsContainer);
    }

    /// <summary>
    /// Only populates the tab when they are selected, which reduces lagspike when not looking at attributions.
    /// </summary>
    private void OnTabChanged(int tab)
    {
        if (tab == Ss14ContributorsTab.GetPositionInParent())
            PopulateContributors(Ss14ContributorsContainer);
        else if (tab == PatronsTab.GetPositionInParent())
            PopulatePatrons(PatronsContainer);
        else if (tab == LicensesTab.GetPositionInParent())
            PopulateLicenses(LicensesContainer);
        else if (tab == AttributionsTab.GetPositionInParent())
            PopulateAttributions(AttributionsContainer, 0);
    }

    private async void PopulateAttributions(BoxContainer attributionsContainer, int count)
    {
        attributionsContainer.RemoveAllChildren();

        if (_attributions.Count == 0)
        {
            var rsi = await CollectRSiAttributions();
            var rga = await CollectRgaAttributions();

            _attributions.AddRange(rsi);
            _attributions.AddRange(rga);
        }

        foreach (var message in _attributions.Skip(count).Take(AttributionsSourcesPerPage))
        {
            var rich = new RichTextLabel();
            rich.SetMessage(message);
            attributionsContainer.AddChild(rich);
        }

        var container = new BoxContainer { Orientation = LayoutOrientation.Horizontal };

        var previousPageButton = new Button { Text = Loc.GetString("credits-window-previous-page-button") };
        previousPageButton.OnPressed +=
            _ => PopulateAttributions(attributionsContainer, count - AttributionsSourcesPerPage);

        var nextPageButton = new Button { Text = Loc.GetString("credits-window-next-page-button") };
        nextPageButton.OnPressed +=
            _ => PopulateAttributions(attributionsContainer, count + AttributionsSourcesPerPage);

        if (count - AttributionsSourcesPerPage >= 0)
            container.AddChild(previousPageButton);
        if (count + AttributionsSourcesPerPage < _attributions.Count)
            container.AddChild(nextPageButton);

        attributionsContainer.AddChild(container);
    }

    private Task<List<FormattedMessage>> CollectRSiAttributions()
    {
        return Task.Run(() =>
        {
            var rsiStreams = _resourceManager.ContentFindFiles("/Textures/")
                .Where(p => p.ToString().EndsWith(".rsi/meta.json"));

            var attrs = new List<FormattedMessage>();

            foreach (var stream in rsiStreams)
            {
                try
                {
                    var m = new FormattedMessage();

                    var yamlStream = _resourceManager.ContentFileReadYaml(stream);

                    if (yamlStream.Documents[0].RootNode.ToDataNode() is not MappingDataNode map)
                        throw new Exception("meta.json is not a mapping.");

                    if (!map.TryGet("copyright", out var copyrightNode))
                        throw new Exception("Missing the copyright field.");

                    if (!map.TryGet("states", out var statesNode))
                        throw new Exception("Missing the states field.");

                    if (statesNode is not SequenceDataNode states)
                        throw new Exception("Missing a list of states.");

                    var copyright = copyrightNode.ToString();
                    var files = states.Select(n => (MappingDataNode)n)
                        .Select(n => n.Get("name") + ".png");

                    m.AddMarkupPermissive(_loc.GetString("credits-window-attributions-directory",
                        ("directory", stream.Directory.ToString())));
                    m.AddText("\n");
                    m.AddMarkupPermissive(_loc.GetString("credits-window-attributions-files",
                        ("files", string.Join(", ", files))));
                    m.AddText("\n");
                    m.AddMarkupPermissive(_loc.GetString("credits-window-attributions-copyright",
                        ("copyright", copyright)));
                    m.AddText("\n");

                    attrs.Add(m);
                }
                catch (Exception e)
                {
                    var m = new FormattedMessage();
                    m.AddMarkupPermissive(_loc.GetString("credits-window-attributions-failed",
                        ("file", stream.ToString())));
                    m.AddText("\n");
                    _sawmill.Error($"{stream.ToString()}\n{e}");
                    attrs.Add(m);
                }
            }

            return attrs;
        });
    }

    private Task<List<FormattedMessage>> CollectRgaAttributions()
    {
        return Task.Run(() =>
        {
            var rgaStreams = _resourceManager.ContentFindFiles("/")
                .Where(p => p.Filename == "attributions.yml");

            var attrs = new List<FormattedMessage>();

            foreach (var stream in rgaStreams)
            {
                try
                {
                    var yamlStream = _resourceManager.ContentFileReadYaml(stream);

                    if (yamlStream.Documents[0].RootNode.ToDataNode() is not SequenceDataNode sequence)
                        throw new Exception("Attributions file is not a list of attributions.");

                    foreach (var attribution in sequence.Sequence)
                    {
                        var m = new FormattedMessage();

                        if (attribution is not MappingDataNode map)
                            throw new Exception("Attribution is not a mapping.");

                        if (!map.TryGet("files", out var filesNode))
                            throw new Exception("Attribution does not list files.");

                        if (!map.TryGet("copyright", out var copyrightNode))
                            throw new Exception("Attribution does not copyright.");

                        if (!map.TryGet("license", out var licenseNode))
                            throw new Exception("Attribution does not identify a license.");

                        if (!map.TryGet("source", out var sourceNode))
                            throw new Exception("Attribution does not identify a source.");

                        var files = _serialization.Read<string[]>(filesNode, notNullableOverride: true);
                        var copyright = copyrightNode.ToString();
                        var license = licenseNode.ToString();
                        var source = sourceNode.ToString();

                        m.AddMarkupPermissive(_loc.GetString("credits-window-attributions-directory",
                            ("directory", stream.Directory.ToString())));
                        m.AddText("\n");
                        m.AddMarkupPermissive(_loc.GetString("credits-window-attributions-files",
                            ("files", string.Join(", ", files))));
                        m.AddText("\n");
                        m.AddMarkupPermissive(_loc.GetString("credits-window-attributions-copyright",
                            ("copyright", copyright)));
                        m.AddText("\n");
                        m.AddMarkupPermissive(
                            _loc.GetString("credits-window-attributions-license", ("license", license)));
                        m.AddText("\n");
                        m.AddMarkupPermissive(_loc.GetString("credits-window-attributions-source", ("source", source)));
                        m.AddText("\n");

                        attrs.Add(m);
                    }
                }
                catch (Exception e)
                {
                    var m = new FormattedMessage();
                    m.AddMarkupPermissive(_loc.GetString("credits-window-attributions-failed",
                        ("file", stream.ToString())));
                    m.AddText("\n");
                    _sawmill.Error($"{stream.ToString()}\n{e}");
                    attrs.Add(m);
                }
            }

            return attrs;
        });
    }

    private void PopulateLicenses(BoxContainer licensesContainer)
    {
        licensesContainer.RemoveAllChildren();

        foreach (var entry in CreditsManager.GetLicenses(_resourceManager).OrderBy(p => p.Name))
        {
            licensesContainer.AddChild(new Label
                { StyleClasses = { StyleBase.StyleClassLabelHeading }, Text = entry.Name });

            // We split these line by line because otherwise
            // the LGPL causes Clyde to go out of bounds in the rendering code.
            foreach (var line in entry.License.Split("\n"))
            {
                licensesContainer.AddChild(new Label { Text = line, FontColorOverride = new Color(200, 200, 200) });
            }
        }
    }

    private void PopulatePatrons(BoxContainer patronsContainer)
    {
        patronsContainer.RemoveAllChildren();

        var patrons = LoadPatrons();

        // Do not show "become a patron" button on Steam builds
        // since Patreon violates Valve's rules about alternative storefronts.
        var linkPatreon = _cfg.GetCVar(CCVars.InfoLinksPatreon);
        if (!_cfg.GetCVar(CCVars.BrandingSteam) && linkPatreon != "")
        {
            Button patronButton;
            patronsContainer.AddChild(patronButton = new Button
            {
                Text = Loc.GetString("credits-window-become-patron-button"),
                HorizontalAlignment = HAlignment.Center,
            });

            patronButton.OnPressed +=
                _ => IoCManager.Resolve<IUriOpener>().OpenUri(linkPatreon);
        }

        var first = true;
        foreach (var tier in patrons.GroupBy(p => p.Tier).OrderBy(p => PatronTierPriority[p.Key]))
        {
            if (!first)
                patronsContainer.AddChild(new Control { MinSize = new Vector2(0, 10) });

            first = false;
            patronsContainer.AddChild(new Label
                { StyleClasses = { StyleBase.StyleClassLabelHeading }, Text = $"{tier.Key}" });

            var msg = string.Join(", ", tier.OrderBy(p => p.Name).Select(p => p.Name));

            var label = new RichTextLabel();
            label.SetMessage(msg);

            patronsContainer.AddChild(label);
        }
    }

    private IEnumerable<PatronEntry> LoadPatrons()
    {
        var yamlStream = _resourceManager.ContentFileReadYaml(new ResPath("/Credits/Patrons.yml"));
        var sequence = (YamlSequenceNode)yamlStream.Documents[0].RootNode;

        return sequence
            .Cast<YamlMappingNode>()
            .Select(m => new PatronEntry(m["Name"].AsString(), m["Tier"].AsString()));
    }

    private void PopulateContributors(BoxContainer ss14ContributorsContainer)
    {
        ss14ContributorsContainer.RemoveAllChildren();

        Button contributeButton;

        ss14ContributorsContainer.AddChild(new BoxContainer
        {
            Orientation = LayoutOrientation.Horizontal,
            HorizontalAlignment = HAlignment.Center,
            SeparationOverride = 20,
            Children =
            {
                new Label { Text = Loc.GetString("credits-window-contributor-encouragement-label") },
                (contributeButton = new Button { Text = Loc.GetString("credits-window-contribute-button") }),
            },
        });

        var first = true;

        void AddSection(string title, string path, bool markup = false)
        {
            if (!first)
                ss14ContributorsContainer.AddChild(new Control { MinSize = new Vector2(0, 10) });

            first = false;
            ss14ContributorsContainer.AddChild(new Label
                { StyleClasses = { StyleBase.StyleClassLabelHeading }, Text = title });

            var label = new RichTextLabel();
            var text = _resourceManager.ContentFileReadAllText($"/Credits/{path}");
            if (markup)
                label.SetMessage(FormattedMessage.FromMarkupOrThrow(text.Trim()));
            else
                label.SetMessage(text);

            ss14ContributorsContainer.AddChild(label);
        }

        AddSection(Loc.GetString("credits-window-contributors-section-title"), "GitHub.txt");
        AddSection(Loc.GetString("credits-window-codebases-section-title"), "SpaceStation13.txt");
        AddSection(Loc.GetString("credits-window-original-remake-team-section-title"), "OriginalRemake.txt");
        AddSection(Loc.GetString("credits-window-immortals-title"), "Immortals.txt", true);
        AddSection(Loc.GetString("credits-window-special-thanks-section-title"), "SpecialThanks.txt", true);

        var linkGithub = _cfg.GetCVar(CCVars.InfoLinksGithub);

        contributeButton.OnPressed += _ =>
            IoCManager.Resolve<IUriOpener>().OpenUri(linkGithub);

        if (linkGithub == "")
            contributeButton.Visible = false;
    }

    private sealed class PatronEntry
    {
        public string Name { get; }
        public string Tier { get; }

        public PatronEntry(string name, string tier)
        {
            Name = name;
            Tier = tier;
        }
    }
}