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

let
  # Path to environment file
  AiRepoEnv = flakeRoot + "/assets/conf/apps/ai/ai.env";

  # Environment file parser
  parseEnv = lines:
    lib.foldl' (acc: line:
      let
        trimmed = builtins.trim line;
      in
      if trimmed == "" || (builtins.stringLength trimmed) > 0 && (builtins.substr 0 1 trimmed) == "#"
      then acc
      else
        let parts = builtins.split "=" trimmed;
        in
        if builtins.length parts >= 2
        then builtins.add (builtins.elemAt parts 0) (builtins.elemAt parts 1) acc
        else acc
    ) { } (builtins.split "\n" (builtins.readFile (toString AiRepoEnv)));

  envVars = parseEnv;
in
{
  # Install required packages
  home.packages = [
    pkgs.ollama-vulkan
    pkgs.zed-editor
  ];

  # Set environment variables
  home.sessionVariables = {
    OLLAMA_HOST = envVars.OLLAMA_HOST or "http://127.0.0.1:11434";
    MISTRAL_API_KEY = envVars.MISTRAL_API_KEY or "";
  };

  # Configure Ollama service using the correct Home Manager syntax
  systemd.user.services.ollama = {
    Unit = {
      Description = "Ollama service for local AI models";
      After = [ "network.target" ];
      Wants = [ "network.target" ];
    };

    Service = {
      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";
    };

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

  # ZED configuration
  home.file.".config/zed/settings.json".text = lib.mkForce (
    builtins.toJSON {
      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:
  #    To add more models later, run:
  #      ollama pull <model-name>
  #    Example: ollama pull llama3:8b
  #
  # 2. Switching GPU Backends:
  #    - For NVIDIA: Replace all `ollama-vulkan` with `ollama` (uses CUDA)
  #    - For AMD: Use `ollama-rocm` and ensure ROCm is installed
  #
  # 3. ZED Plugin Setup:
  #    - Install the Ollama and Mistral plugins in ZED via the plugin marketplace
  #    - The Ollama plugin will use the local models pulled above
  #    - The Mistral plugin will use the MISTRAL_API_KEY for cloud access
  #
  # 4. Security:
  #    - Never commit ./assets/conf/apps/ai.env to version control
  #    - For extra security, encrypt ai.env using sops-nix or age
  #
  # 5. Persistent Service:
  #    To keep Ollama running after logout, enable lingering:
  #      loginctl enable-linger $(whoami)
}