using System.Text.Json;
using PrintServiceTray.Models;

namespace PrintServiceTray.Services;

public class ConfigurationService
{
    private readonly string _globalConfigPath;
    private readonly string _localConfigPath;

    public ConfigurationService()
    {
        // Global config: next to CLI executable (C:\LAAPC or wherever installed)
        var cliPath = Path.Combine(
            Environment.GetFolderPath(Environment.SpecialFolder.CommonApplicationData),
            "LAAPC"
        );
        _globalConfigPath = Path.Combine(cliPath, "printer-config.json");

        // Local config: user's AppData
        var appDataPath = Path.Combine(
            Environment.GetFolderPath(Environment.SpecialFolder.LocalApplicationData),
            "LAAPC"
        );
        Directory.CreateDirectory(appDataPath);
        _localConfigPath = Path.Combine(appDataPath, "printer-config.json");
    }

    /// <summary>
    /// Load configuration (local overrides global)
    /// </summary>
    public PrinterConfiguration Load()
    {
        var config = new PrinterConfiguration();

        // Load global first
        if (File.Exists(_globalConfigPath))
        {
            try
            {
                var json = File.ReadAllText(_globalConfigPath);
                var globalConfig = JsonSerializer.Deserialize<PrinterConfiguration>(json);
                if (globalConfig != null)
                {
                    config = globalConfig;
                }
            }
            catch { }
        }

        // Load local and merge/override
        if (File.Exists(_localConfigPath))
        {
            try
            {
                var json = File.ReadAllText(_localConfigPath);
                var localConfig = JsonSerializer.Deserialize<PrinterConfiguration>(json);
                if (localConfig != null)
                {
                    // Merge: local overrides global for matching document types
                    foreach (var kvp in localConfig.DocumentTypes)
                    {
                        config.DocumentTypes[kvp.Key] = kvp.Value;
                    }
                }
            }
            catch { }
        }

        return config;
    }

    /// <summary>
    /// Save configuration to global or local
    /// </summary>
    public void Save(PrinterConfiguration config, bool saveGlobal)
    {
        var path = saveGlobal ? _globalConfigPath : _localConfigPath;
        
        // Ensure directory exists
        var directory = Path.GetDirectoryName(path);
        if (!string.IsNullOrEmpty(directory))
        {
            Directory.CreateDirectory(directory);
        }

        var options = new JsonSerializerOptions
        {
            WriteIndented = true
        };
        var json = JsonSerializer.Serialize(config, options);
        File.WriteAllText(path, json);
    }

    /// <summary>
    /// Get all installed printers
    /// </summary>
    public List<string> GetInstalledPrinters()
    {
        var printers = new List<string>();
        try
        {
            foreach (string printerName in System.Drawing.Printing.PrinterSettings.InstalledPrinters)
            {
                printers.Add(printerName);
            }
        }
        catch { }
        return printers;
    }

    /// <summary>
    /// Get available trays for a printer
    /// </summary>
    public List<(int Number, string Name)> GetPrinterTrays(string printerName)
    {
        var trays = new List<(int, string)>();
        try
        {
            var printerSettings = new System.Drawing.Printing.PrinterSettings
            {
                PrinterName = printerName
            };

            foreach (System.Drawing.Printing.PaperSource source in printerSettings.PaperSources)
            {
                trays.Add((source.RawKind, source.SourceName));
            }
        }
        catch { }
        return trays;
    }

    public string GlobalConfigPath => _globalConfigPath;
    public string LocalConfigPath => _localConfigPath;
}