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

let
  # Read environment variables (OLLAMA_HOST and MISTRAL_API_KEY) from a local file.
  AiRepoEnv = flakeRoot + "/assets/conf/apps/ai/ai.env";
  AiRepoConf = flakeRoot + "/assets/conf/apps/ai/ai.conf";
  envVars = lib.genAttrs (builtins.splitStrings "\n" (builtins.readFile (toString AiRepoEnv)))
    (nameValue: builtins.splitString "=" nameValue);
in
{
  # Install ZED editor and Ollama with Vulkan support (for CPU/AMD).
  home.packages = [
    pkgs.ollama-vulkan
    pkgs.zed
  ];

  # --- Environment Variables ---
  home.sessionVariables = {
    OLLAMA_HOST = envVars.OLLAMA_HOST or "http://127.0.0.1:11434";
    MISTRAL_API_KEY = envVars.MISTRAL_API_KEY or "";
  };

  # --- Ollama User Service ---
  systemd.user.services.ollama = {
    description = "Ollama service for local AI models";
    wantedBy = [ "default.target" ];
    after = [ "network.target" ];

    serviceConfig = {
      Type = "forking";

      ExecStart = ''
        ${pkgs.ollama-vulkan}/bin/ollama serve
      '';

      ExecStartPost = ''
        sleep 5

        ${pkgs.ollama-vulkan}/bin/ollama pull codellama:70b
        ${pkgs.ollama-vulkan}/bin/ollama pull mixtral:8x7b
      '';
      Restart = "on-failure";
    };
  };

  # --- ZED Configuration ---
  home.file.".config/zed/settings.json".text = lib.mkForce (
    builtins.toJSON (
      (builtins.fromJSON (builtins.readFile (toString AiRepoConf)))
      // {
        mistral = {
          apiKey = envVars.MISTRAL_API_KEY or "";
          defaultModel = "mistral-pro";
        };
        ollama = {
          endpoint = envVars.OLLAMA_HOST or "http://127.0.0.1:11434";
          defaultModel = "codellama:70b";
        };
      }
    )
  );

  # --- Usage Notes ---
  # 1. Pulling Additional Models:
  #    ollama pull <model-name>
  # 2. Switching GPU Backends:
  #    - NVIDIA: Replace `ollama-vulkan` with `ollama`
  #    - AMD: Use `ollama-rocm` and ensure ROCm is installed
  # 3. ZED Plugin Setup:
  #    - Install Ollama and Mistral plugins in ZED
  # 4. Security:
  #    - Never commit ai.env to version control
  # 5. Persistent Service:
  #    loginctl enable-linger $(whoami)
}