{ config, lib, pkgs, ... }:

let
  cfg = config.services.usda-vision;
  
  # Get packages from the flake (self reference)
  camera-sdk = config.services.usda-vision.package.camera-sdk or pkgs.callPackage ./camera-sdk.nix {};
  usda-vision-app = config.services.usda-vision.package.usda-vision or pkgs.callPackage ./package.nix {};
in

{
  options.services.usda-vision = {
    enable = lib.mkEnableOption "USDA Vision system";
    
    package = lib.mkOption {
      type = lib.types.attrs;
      default = {};
      description = "Package set containing camera-sdk and usda-vision packages";
    };
    
    hostname = lib.mkOption {
      type = lib.types.str;
      default = "exp-dash";
      description = "Hostname or IP address to replace exp-dash and localhost with in configuration";
    };
    
    replaceHostnames = lib.mkOption {
      type = lib.types.bool;
      default = false;
      description = "Whether to replace exp-dash and localhost hostnames with the configured hostname";
    };
    
    envFile = lib.mkOption {
      type = lib.types.nullOr lib.types.path;
      default = null;
      description = "Path to environment file (managed by ragenix in deployment)";
    };
  };

  config = lib.mkIf cfg.enable {
    # System packages
    environment.systemPackages = with pkgs; [
      docker
      docker-compose
      supabase-cli
      camera-sdk
      usda-vision-app
    ];
    
    # Make camera SDK libraries available system-wide
    environment.variables = {
      LD_LIBRARY_PATH = "${camera-sdk}/lib";
    };

    # Enable Docker service
    virtualisation.docker = {
      enable = true;
      autoPrune.enable = true;
      daemon.settings = {
        experimental = true;
      };
    };

    # Create persistent directories
    systemd.tmpfiles.rules = [
      "d /var/lib/usda-vision 0755 root root -"
      "f /var/lib/usda-vision/.env 0644 root root -"
      "d /var/lib/supabase 0755 root root -"
    ];

    # Supabase CLI service
    systemd.services.supabase-cli = {
      enable = true;
      description = "Supabase CLI Service";
      
      preStart = ''
        rm -rf /var/lib/supabase/*
        rm -rf /var/lib/supabase/.* 2>/dev/null || true
        
        if [ -d ${usda-vision-app}/opt/usda-vision/supabase ]; then
          ${pkgs.rsync}/bin/rsync -av ${usda-vision-app}/opt/usda-vision/supabase/ /var/lib/supabase/supabase/
        fi
        
        mkdir -p /var/lib/supabase/supabase/.branches
        chmod -R 755 /var/lib/supabase
      '';
      
      serviceConfig = {
        WorkingDirectory = "/var/lib/supabase";
        EnvironmentFile = lib.mkIf (cfg.envFile != null) cfg.envFile;
        ExecStart = "${pkgs.supabase-cli}/bin/supabase start";
        ExecStop = "${pkgs.supabase-cli}/bin/supabase stop";
        Type = "oneshot";
        RemainAfterExit = true;
        User = "root";
        Group = "root";
      };
    };

    # USDA Vision docker compose service
    systemd.services.usda-vision = {
      description = "USDA Vision Docker Compose Stack";
      after = [ "docker.service" "network-online.target" "systemd-tmpfiles-setup.service" ];
      wants = [ "network-online.target" ];
      wantedBy = [ "multi-user.target" ];
      
      unitConfig = lib.mkIf (cfg.envFile != null) {
        ConditionPathExists = cfg.envFile;
      };
      
      preStart = ''
        echo "Syncing application code to /var/lib/usda-vision..."
        ${pkgs.rsync}/bin/rsync -av --delete \
          --checksum \
          --exclude='node_modules' \
          --exclude='.env' \
          --exclude='.env.azure' \
          --exclude='__pycache__' \
          --exclude='.venv' \
          ${usda-vision-app}/opt/usda-vision/ /var/lib/usda-vision/
        
        ${lib.optionalString cfg.replaceHostnames ''
          echo "Replacing hostnames (exp-dash, localhost) with ${cfg.hostname} in docker-compose.yml..."
          ${pkgs.gnused}/bin/sed -i \
            -e 's|exp-dash|${cfg.hostname}|g' \
            -e 's|localhost|${cfg.hostname}|g' \
            /var/lib/usda-vision/docker-compose.yml
        ''}
        
        ${lib.optionalString (cfg.envFile != null) ''
          echo "Copying environment file from managed secret..."
          cp ${cfg.envFile} /var/lib/usda-vision/.env
          chmod 644 /var/lib/usda-vision/.env
        ''}
        
        ${lib.optionalString (cfg.envFile == null) ''
          if [ ! -s /var/lib/usda-vision/.env ]; then
            if [ -f ${usda-vision-app}/opt/usda-vision/.env.example ]; then
              echo "WARNING: No environment file provided, using .env.example"
              cp ${usda-vision-app}/opt/usda-vision/.env.example /var/lib/usda-vision/.env
            fi
          fi
        ''}
      '';

      serviceConfig = {
        Type = "oneshot";
        RemainAfterExit = true;
        WorkingDirectory = "/var/lib/usda-vision";
        User = "root";
        Group = "root";
        ExecStart = "${pkgs.docker-compose}/bin/docker-compose -f /var/lib/usda-vision/docker-compose.yml up -d --build";
        ExecStop = "${pkgs.docker-compose}/bin/docker-compose -f /var/lib/usda-vision/docker-compose.yml down";
        ExecReload = "${pkgs.bash}/bin/bash -c '${pkgs.docker-compose}/bin/docker-compose -f /var/lib/usda-vision/docker-compose.yml down && ${pkgs.docker-compose}/bin/docker-compose -f /var/lib/usda-vision/docker-compose.yml up -d --build'";
        TimeoutStartSec = 300;
        TimeoutStopSec = 120;
      };
    };
  };
}