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

let
  ollamaModelDir = "/mnt/models/ollama"; # ✅ change to your external disk or large partition
  modelsToInstall = [
    "llama3"
    "mistral"
    "codellama"
    "gemma"
  ];
  cfg = config.homeModules.llm;
in

lib.mkIf cfg.enable {
  home.packages = with pkgs; [
    ollama
    opencode
  ];

  # Set up environment variables
  home.sessionVariables = {
    OLLAMA_MODELS = ollamaModelDir;
    OLLAMA_HOST = "127.0.0.1:11434";
  };

  # Systemd user service for ollama daemon
  systemd.user.services.ollama = {
    Unit = {
      Description = "Ollama LLM Inference Daemon";
      After = [ "network.target" ];
    };

    Service = {
      ExecStart = "${pkgs.ollama}/bin/ollama serve";
      Environment = [
        "OLLAMA_MODELS=${ollamaModelDir}"
        "OLLAMA_HOST=127.0.0.1:11434"
      ];
      Restart = "on-failure";
    };

    Install = {
      WantedBy = [ "default.target" ];
    };
  };

  # Setup ollama models via activation script
  home.activation.installOllamaModels = lib.hm.dag.entryAfter [ "writeBoundary" ] ''
    export OLLAMA_MODELS=${ollamaModelDir}
    export OLLAMA_HOST=127.0.0.1:11434

    mkdir -p ${ollamaModelDir}

    echo "⏳ Checking and pulling ollama models..."
    for model in ${builtins.toString modelsToInstall}; do
      if ! ${pkgs.ollama}/bin/ollama list | grep -q "$model"; then
        ${pkgs.ollama}/bin/ollama pull "$model"
      fi
    done
  '';

  # Optional aliases for quick usage
  programs.zsh.shellAliases = {
    llm = "opencode";
    ollama-ui = "xdg-open http://localhost:11434";
  };
}