using ModVersionChecker.model;
using System.Text.Json;
using System.Text.RegularExpressions;

namespace ModVersionChecker.utils
{
    public static class VersionUtils
    {
        public static string GetCurrentVersion(App app, TypeConfig typeConfig)
        {
            var versionConfig = app.Fields;
            var packageName = versionConfig["package"];
            var fsPath = typeConfig.ConfigValues.GetValueOrDefault("path", "");
            var fsFile = typeConfig.ConfigValues.GetValueOrDefault("filename");
            var fsFileType = typeConfig.ConfigValues.GetValueOrDefault("filetype", "");
            var fsKey = typeConfig.ConfigValues.GetValueOrDefault("jsonkey", "");
            
            var filePath = Path.GetFullPath(Path.Combine(fsPath, packageName, fsFile));

            if (!File.Exists(filePath))
            {
                return ""; // Fallback
            }

            try
            {
                var content = File.ReadAllText(filePath).Trim();
                if (string.IsNullOrEmpty(content))
                {
                    throw new Exception($"Empty file: {filePath}");
                }
                
                using var jsonDoc = JsonDocument.Parse(content);
                var element = jsonDoc.RootElement;
                foreach (var key in fsKey.Split('.'))
                {
                    if (!element.TryGetProperty(key, out var nextElement))
                    {
                        throw new Exception($"JSON key '{key}' not found in {filePath}");
                    }
                    element = nextElement;
                }
                if (element.ValueKind != JsonValueKind.String)
                {
                    throw new Exception($"JSON value for '{fsKey}' is not a string in {filePath}");
                }

                var version = element.GetString()!;               

                return version;
            }
            catch (Exception ex)
            {
                throw new Exception($"Error reading or processing file '{filePath}': {ex.Message}");
            }
        }
    }
}