{ inputs, ... }:

# ============================================================================
# USDA Dashboard External System Module
# ============================================================================
# External system configuration for usda-dash
# This module can be referenced from nixos-systems/inventory.nix using:
#
#   nix-lxc = {
#     devices = {
#       "usda-dash" = builtins.fetchGit {
#         url = "https://git.factory.uga.edu/MODEL/usda-dash-config.git";
#         rev = "commit-hash";
#       };
#     };
#   };

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

let
  # Create a derivation that packages the usda-vision directory
  usda-vision-app = pkgs.stdenv.mkDerivation {
    pname = "usda-vision";
    version = "1.0.0";
    
    # Use the directory from this repository
    src = ./usda-vision;
    
    nativeBuildInputs = [ pkgs.makeWrapper ];
    
    installPhase = ''
      mkdir -p $out/opt/usda-vision
      
      # Copy all application files
      cp -r $src/* $out/opt/usda-vision/
      
      # Create convenience scripts
      mkdir -p $out/bin
      
      cat > $out/bin/usda-vision-start <<'EOF'
      #!/usr/bin/env bash
      cd $out/opt/usda-vision
      ${pkgs.docker-compose}/bin/docker-compose up -d --build
      EOF
      
      cat > $out/bin/usda-vision-stop <<'EOF'
      #!/usr/bin/env bash
      cd $out/opt/usda-vision
      ${pkgs.docker-compose}/bin/docker-compose down
      EOF
      
      cat > $out/bin/usda-vision-logs <<'EOF'
      #!/usr/bin/env bash
      cd $out/opt/usda-vision
      ${pkgs.docker-compose}/bin/docker-compose logs -f "$@"
      EOF
      
      cat > $out/bin/usda-vision-restart <<'EOF'
      #!/usr/bin/env bash
      cd $out/opt/usda-vision
      ${pkgs.docker-compose}/bin/docker-compose restart "$@"
      EOF
      
      chmod +x $out/bin/usda-vision-*
    '';
    
    meta = {
      description = "USDA Vision camera management system";
      maintainers = [ "UGA Innovation Factory" ];
    };
  };
in

{
  # ========== Module Configuration ==========
  config = {
    # System packages specific to usda-dash
    environment.systemPackages = with pkgs; [
      # Core tools
      git
      vim
      htop
      curl
      wget
      
      # Docker and Docker Compose for running usda-vision
      docker
      docker-compose
      
      # USDA Vision application package with convenience scripts
      usda-vision-app
    ];

    # Enable Docker service
    virtualisation.docker = {
      enable = true;
      autoPrune.enable = true;
    };
    # Configure users
    athenix.users.sv22900.enable = true;
    athenix.users.hdh20267.enable = true;

    # Add users to docker group
    users.users.sv22900.extraGroups = [ "docker" ];

    # Create persistent directories and .env file location
    systemd.tmpfiles.rules = [
      "d /var/lib/usda-vision 0755 root root -"
      "f /var/lib/usda-vision/.env 0644 root root -"
      "L+ ${usda-vision-app}/opt/usda-vision/management-dashboard-web-app/.env - - - - /var/lib/usda-vision/.env"
    ];

    # Systemd service to manage usda-vision docker compose
    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" ];
      
      preStart = ''
        # Ensure .env file exists with defaults if empty
        if [ ! -s /var/lib/usda-vision/.env ]; then
          if [ -f ${usda-vision-app}/opt/usda-vision/.env.example ]; then
            echo "Copying .env.example to /var/lib/usda-vision/.env"
            cp ${usda-vision-app}/opt/usda-vision/.env.example /var/lib/usda-vision/.env
            echo "Please edit /var/lib/usda-vision/.env with your configuration"
          fi
        fi
      '';
      
      serviceConfig = {
        Type = "oneshot";
        RemainAfterExit = true;
        WorkingDirectory = "${usda-vision-app}/opt/usda-vision";
        User = "root";
        Group = "root";
        
        # Start: pull latest images and start containers
        ExecStart = "${pkgs.docker-compose}/bin/docker-compose up -d --build";
        
        # Stop: gracefully stop containers
        ExecStop = "${pkgs.docker-compose}/bin/docker-compose down";
        
        # Reload: restart containers
        ExecReload = "${pkgs.bash}/bin/bash -c '${pkgs.docker-compose}/bin/docker-compose down && ${pkgs.docker-compose}/bin/docker-compose up -d --build'";
        
        TimeoutStartSec = 300;
        TimeoutStopSec = 120;
      };
    };

    # Firewall configuration
    # networking.firewall.allowedTCPPorts = [ 80 443 ];

    # Any other usda-dash specific configuration
  };
}