namespace OmniNX.DesktopInstaller.Services;

public sealed class ConfigIniService
{
    private const string ConfigIniRelative = @"config\omninx\config.ini";
    private const string LegacyRamConfigRelative = @"config\omninx\ram_config.ini";

    public bool TryReadBool(string driveRoot, string section, string key, out bool value)
    {
        value = false;
        var path = PathUtils.ToDrivePath(driveRoot, ConfigIniRelative);
        if (!File.Exists(path))
            return false;

        var inSection = false;
        foreach (var rawLine in File.ReadLines(path))
        {
            var line = rawLine.Trim();
            if (line.Length == 0)
                continue;

            if (line.StartsWith('[') && line.EndsWith(']'))
            {
                inSection = line[1..^1].Equals(section, StringComparison.Ordinal);
                continue;
            }

            if (!inSection)
                continue;

            var eq = line.IndexOf('=');
            if (eq <= 0)
                continue;

            var k = line[..eq].Trim();
            if (!k.Equals(key, StringComparison.Ordinal))
                continue;

            var val = line[(eq + 1)..].Trim();
            if (val == "1")
            {
                value = true;
                return true;
            }

            if (val == "0")
            {
                value = false;
                return true;
            }

            return false;
        }

        return false;
    }

    public void MigrateLegacyRamConfig(string driveRoot)
    {
        var legacy = PathUtils.ToDrivePath(driveRoot, LegacyRamConfigRelative);
        if (!File.Exists(legacy))
            return;

        if (TryReadLegacyBool(legacy, "Ram", "8gb", out var use8Gb))
        {
            var havePro = TryReadBool(driveRoot, "HekateAms", "pro", out var usePro);
            WriteExtras(driveRoot, needRam: true, use8Gb, needHekateAms: havePro, havePro ? usePro : false);
        }

        PathUtils.DeletePath(legacy);
    }

    public void WriteExtras(string driveRoot, bool needRam, bool use8Gb, bool needHekateAms, bool usePro)
    {
        var path = PathUtils.ToDrivePath(driveRoot, ConfigIniRelative);
        PathUtils.EnsureDirectory(Path.GetDirectoryName(path)!);

        using var writer = new StreamWriter(path, append: false);
        if (needRam)
        {
            writer.WriteLine("[Ram]");
            writer.WriteLine($"8gb={(use8Gb ? 1 : 0)}");
            writer.WriteLine();
        }

        if (needHekateAms)
        {
            writer.WriteLine("[HekateAms]");
            writer.WriteLine($"pro={(usePro ? 1 : 0)}");
        }
    }

    private static bool TryReadLegacyBool(string path, string section, string key, out bool value)
    {
        value = false;
        var inSection = false;
        foreach (var rawLine in File.ReadLines(path))
        {
            var line = rawLine.Trim();
            if (line.StartsWith('[') && line.EndsWith(']'))
            {
                inSection = line[1..^1].Equals(section, StringComparison.Ordinal);
                continue;
            }

            if (!inSection)
                continue;

            var eq = line.IndexOf('=');
            if (eq <= 0)
                continue;

            if (!line[..eq].Trim().Equals(key, StringComparison.Ordinal))
                continue;

            var val = line[(eq + 1)..].Trim();
            if (val == "1")
            {
                value = true;
                return true;
            }

            if (val == "0")
            {
                value = false;
                return true;
            }
        }

        return false;
    }
}