# steam-rom-manager.nix
{ config, lib, pkgs, ... }:

with lib;

let
  cfg = config.programs.steam-rom-manager;

  # Common emulator configurations
  commonEmulatorConfigs = {
    ryujinx = {
      romFolder = "switch";
      binaryName = "Ryujinx";
      fileTypes = [ ".nca" ".NCA" ".nro" ".NRO" ".nso" ".NSO" ".nsp" ".NSP" ".xci" ".XCI" ];
    };
    yuzu = {
      romFolder = "switch";
      binaryName = "yuzu";
      fileTypes = [ ".nsp" ".NSP" ".xci" ".XCI" ];
    };
    pcsx2 = {
      romFolder = "ps2";
      binaryName = "pcsx2-qt";
      fileTypes = [ ".iso" ".ISO" ".bin" ".BIN" ".chd" ".CHD" ];
    };
    rpcs3 = {
      romFolder = "ps3";
      binaryName = "rpcs3";
      fileTypes = [ ".iso" ".ISO" ".bin" ".BIN" ".pkg" ".PKG" ];
    };
    dolphin-emu = {
      romFolder = "gc";
      binaryName = "dolphin-emu";
      fileTypes = [ ".iso" ".ISO" ".gcm" ".GCM" ".ciso" ".CISO" ];
    };
    duckstation = {
      romFolder = "psx";
      binaryName = "duckstation-qt";
      fileTypes = [ ".iso" ".ISO" ".bin" ".BIN" ".chd" ".CHD" ".pbp" ".PBP" ];
    };
    melonDS = {
      romFolder = "nds";
      binaryName = "melonDS";
      fileTypes = [ ".nds" ".NDS" ];
    };
    cemu = {
      romFolder = "wiiu";
      binaryName = "cemu";
      fileTypes = [ ".wud" ".WUD" ".wux" ".WUX" ".rpx" ".RPX" ];
    };
  };

  getFileTypes = name: emu:
    if (emu.fileTypes or []) != []
    then emu.fileTypes
    else commonEmulatorConfigs.${name}.fileTypes or [];

  mkParserConfig = name: emu: 
  let
    # We create an ordered list of key-value pairs that will maintain the exact order
    # in the generated JSON output. Each field is documented for clarity.
    orderedConfig = [
      # Basic parser configuration
      { name = "parserType"; value = "Glob"; }
      { name = "configTitle"; value = name; }
      { name = "steamDirectory"; value = "\${steamdirglobal}"; }
      { name = "romDirectory"; value = "${cfg.romsDirectory}/${if emu.romFolder != "" then emu.romFolder else commonEmulatorConfigs.${name}.romFolder}"; }
      { name = "steamCategories"; value = [""]; }
      
      # Executable configuration
      { name = "executableArgs"; value = emu.extraArgs; }
      { name = "executableModifier"; value = "\"\${exePath}\""; }
      { name = "startInDirectory"; value = "${cfg.romsDirectory}/${if emu.romFolder != "" then emu.romFolder else commonEmulatorConfigs.${name}.romFolder}"; }
      { name = "titleModifier"; value = "\${fuzzyTitle}"; }
      
      # Controller settings
      { name = "fetchControllerTemplatesButton"; value = null; }
      { name = "removeControllersButton"; value = null; }
      { name = "steamInputEnabled"; value = "1"; }
      
      # Image provider configuration
      { name = "imageProviders"; value = [ "sgdb" ]; }
      { name = "onlineImageQueries"; value = [ "\${fuzzyTitle}" ]; }
      { name = "imagePool"; value = "\${fuzzyTitle}"; }
      
      # DRM and user account settings
      { name = "drmProtect"; value = false; }
      { name = "userAccounts"; value = {
        specifiedAccounts = [ "Global" ];
      }; }
      
      # Parser-specific settings
      { name = "parserInputs"; value = {
        glob = "\${title}@(${concatStringsSep "|" (getFileTypes name emu)})";
      }; }
      
      # Executable details
      { name = "executable"; value = {
        path = "${emu.package}/bin/${if emu.binaryName != "" then emu.binaryName else commonEmulatorConfigs.${name}.binaryName}";
        shortcutPassthrough = false;
        appendArgsToExecutable = true;
      }; }
      
      # Title and fuzzy matching configuration
      { name = "titleFromVariable"; value = {
        limitToGroups = [];
        caseInsensitiveVariables = false;
        skipFileIfVariableWasNotFound = false;
      }; }
      
      { name = "fuzzyMatch"; value = {
        replaceDiacritics = true;
        removeCharacters = true;
        removeBrackets = true;
      }; }
      
      # Controller configuration
      { name = "controllers"; value = {
        ps4 = null;
        ps5 = null;
        ps5_edge = null;
        xbox360 = null;
        xboxone = null;
        xboxelite = null;
        switch_joycon_left = null;
        switch_joycon_right = null;
        switch_pro = null;
        neptune = null;
        steamcontroller_gordon = null;
      }; }
      
      # Image provider API configuration
      { name = "imageProviderAPIs"; value = {
        sgdb = {
          nsfw = false;
          humor = false;
          styles = [];
          stylesHero = [];
          stylesLogo = [];
          stylesIcon = [];
          imageMotionTypes = [ "static" ];
          sizes = [];
          sizesHero = [];
          sizesTall = null;
          sizesIcon = [];
        };
      }; }
      
      # Default and local image settings
      { name = "defaultImage"; value = {
        tall = "";
        long = "";
        hero = "";
        logo = "";
        icon = "";
      }; }
      
      { name = "localImages"; value = {
        tall = "";
        long = "";
        hero = "";
        logo = "";
        icon = "";
      }; }
      
      # Parser identification
      { name = "parserId"; value = name; }
      { name = "version"; value = 25; }
    ];
    
    # Function to convert our ordered list into properly formatted JSON
    makeOrderedJSON = pairs:
      let
        # Create JSON key-value pairs while preserving order
        joined = builtins.concatStringsSep "," 
          (map (pair: "\"${pair.name}\":${builtins.toJSON pair.value}") pairs);
      in
      "{${joined}}";
  in
    makeOrderedJSON orderedConfig;

  # Create AppImage package
  steam-rom-manager = pkgs.fetchurl {
    name = "steam-rom-manager-2.5.29.AppImage";
    url = "https://github.com/SteamGridDB/steam-rom-manager/releases/download/v2.5.29/Steam-ROM-Manager-2.5.29.AppImage";
    hash = "sha256-6ZJ+MGIgr2osuQuqD6N9NnPiJFNq/HW6ivG8tyXUhvs=";
  };
in {
  options.programs.steam-rom-manager = {
    enable = mkEnableOption "Steam ROM Manager";
    
    package = mkOption {
      type = types.package;
      default = steam-rom-manager;
      description = "Steam ROM Manager package";
    };

    steamUsername = mkOption {
      type = types.str;
      description = "Steam username for configuration";
    };

    romsDirectory = mkOption {
      type = types.str;
      default = "${config.home.homeDirectory}/Emulation/roms";
      description = "Base directory for ROM files";
    };

    steamDirectory = mkOption {
      type = types.str;
      default = "${config.home.homeDirectory}/.local/share/Steam";
      description = "Steam installation directory";
    };

    emulators = mkOption {
      type = types.attrsOf (types.submodule {
        options = {
          enable = mkEnableOption "emulator configuration";
          package = mkOption {
            type = types.package;
            description = "Emulator package";
          };
          binaryName = mkOption {
            type = types.str;
            default = "";
            description = "Name of the emulator binary (defaults to common configuration)";
          };
          romFolder = mkOption {
            type = types.str;
            default = "";
            description = "Name of the ROM folder (defaults to common configuration)";
          };
          fileTypes = mkOption {
            type = types.listOf types.str;
            default = [];
            description = "List of ROM file types (defaults to common configuration)";
          };
          extraArgs = mkOption {
            type = types.str;
            default = "--fullscreen \"\${filePath}\"";
            description = "Additional emulator arguments";
          };
        };
      });
      default = {};
      description = "Emulator configurations";
    };
  };

  config = mkIf cfg.enable {

    home.packages = [ pkgs.appimage-run ]
      ++ mapAttrsToList (_: v: v.package) (filterAttrs (_: v: v.enable) cfg.emulators);

    xdg.desktopEntries.steam-rom-manager = {
      name = "Steam ROM Manager";
      exec = "${pkgs.appimage-run}/bin/appimage-run ${cfg.package}";
      icon = "steam";
      categories = [ "Game" "Utility" ];
      type = "Application";
    };

    # Configuration files using xdg.configFile
    xdg.configFile = {
      # User settings configuration
      "steam-rom-manager/userData/userSettings.json".text = builtins.toJSON {
        fuzzyMatcher = {
          timestamps = {
            check = 0;
            download = 0;
          };
          verbose = false;
          filterProviders = true;
        };
        environmentVariables = {
          steamDirectory = cfg.steamDirectory;
          userAccounts = "\${${cfg.steamUsername}}";
          romsDirectory = cfg.romsDirectory;
          retroarchPath = "";
          raCoresDirectory = "";
          localImagesDirectory = "";
        };
        previewSettings = {
          retrieveCurrentSteamImages = true;
          disableCategories = false;
          deleteDisabledShortcuts = false;
          imageZoomPercentage = 30;
          preload = false;
          hideUserAccount = false;
        };
        enabledProviders = [ "sgdb" "steamCDN" ];
        batchDownloadSize = 50;
        dnsServers = [];
        language = "en-US";
        theme = "Deck";
        emudeckInstall = false;
        autoUpdate = false;
        offlineMode = false;
        navigationWidth = 0;
        clearLogOnTest = true;
        version = 8;
      };

      # Parser configurations
      "steam-rom-manager/userData/userConfigurations.json".text = 
      let
        # Generate configurations
        configs = mapAttrsToList (name: emu: 
          mkParserConfig name (emu // {
            romFolder = if emu.romFolder != "" then emu.romFolder else commonEmulatorConfigs.${name}.romFolder;
            binaryName = if emu.binaryName != "" then emu.binaryName else commonEmulatorConfigs.${name}.binaryName;
          })
        ) (filterAttrs (_: v: v.enable) cfg.emulators);
        
        # Join configurations into a valid JSON array
        configsJson = "[${concatStringsSep "," configs}]";
      in
      configsJson;
    };
  };
}