# Bosun library - Nix-based Nomad job definitions
{
  # Nomad-specific helpers
  nomad = import ./nomad.nix;

  # Discover all jobs in a directory
  # Each subdirectory with a default.nix is treated as a job
  # Jobs can be:
  #   - { lib, nomadLib }: { job.name = {...}; }           # simple job
  #   - { lib, nomadLib, vars }: { job.name = {...}; }     # parameterized job
  discoverJobs = {
    path,
    lib,
    nomadLib ? (import ./nomad.nix {inherit lib;}),
    extraArgs ? {},
  }: let
    # List all entries in the directory
    entries = builtins.readDir path;

    # Filter to directories that have a default.nix
    jobDirs = lib.filterAttrs (name: type:
      type == "directory" && builtins.pathExists (path + "/${name}/default.nix")
    ) entries;

    # Import each job
    importJob = name: let
      jobPath = path + "/${name}";
      jobModule = import jobPath;
    in
      # Return the raw module - evaluation happens later with vars
      jobModule;
  in
    lib.mapAttrs (name: _: importJob name) jobDirs;

  # Evaluate a discovered job with given arguments
  evalJob = {
    job,           # The imported job module (function)
    lib,
    nomadLib ? (import ./nomad.nix {inherit lib;}),
    vars ? {},     # Variables to pass to parameterized jobs
    extraArgs ? {},
  }: let
    # Check function arity to see if it accepts vars
    funcArgs = builtins.functionArgs job;
    hasVars = funcArgs ? vars;

    baseArgs = {inherit lib nomadLib;} // extraArgs;
    fullArgs = if hasVars then baseArgs // {inherit vars;} else baseArgs;
  in
    job fullArgs;

  # Discover and evaluate all jobs (convenience wrapper)
  loadJobs = {
    path,
    lib,
    nomadLib ? (import ./nomad.nix {inherit lib;}),
    vars ? {},     # Global vars passed to all jobs
    extraArgs ? {},
  }: let
    discovered = import ./default.nix;
    jobs = discovered.discoverJobs {inherit path lib nomadLib extraArgs;};
  in
    lib.mapAttrs (name: job:
      discovered.evalJob {inherit job lib nomadLib vars extraArgs;}
    ) jobs;

  # Compile a set of jobs to JSON files
  # jobs: attrset of job definitions { name = { job.name = {...}; }; }
  # pkgs: nixpkgs
  compileJobs = {
    pkgs,
    jobs,
    lib ? pkgs.lib,
  }:
    lib.mapAttrs (
      name: job:
        pkgs.writeText "${name}.nomad.json" (builtins.toJSON job)
    ) jobs;

  # Build a derivation containing all compiled jobs
  compileJobsDir = {
    pkgs,
    jobs,
    lib ? pkgs.lib,
  }: let
    jobFiles = lib.mapAttrs (
      name: job:
        pkgs.writeText "${name}.nomad.json" (builtins.toJSON job)
    ) jobs;
  in
    pkgs.runCommand "nomad-jobs" {} ''
      mkdir -p $out
      ${lib.concatStrings (lib.mapAttrsToList (name: file: ''
          cp ${file} $out/${name}.nomad.json
        '')
        jobFiles)}
    '';

  # Create a script to generate all job files to a directory
  mkGenerateScript = {
    pkgs,
    jobs,
    lib ? pkgs.lib,
  }: let
    jobFiles = lib.mapAttrs (
      name: job:
        pkgs.writeText "${name}.nomad.json" (builtins.toJSON job)
    ) jobs;
  in
    pkgs.writeShellScriptBin "bosun-generate" ''
      set -euo pipefail
      OUTDIR="''${1:-$(pwd)/generated}"
      mkdir -p "$OUTDIR"
      ${lib.concatStrings (lib.mapAttrsToList (name: file: ''
          cp ${file} "$OUTDIR/${name}.nomad.json"
          chmod 644 "$OUTDIR/${name}.nomad.json"
          echo "✓ ${name}.nomad.json"
        '')
        jobFiles)}
      echo ""
      echo "Generated ${toString (lib.length (lib.attrNames jobs))} jobs in $OUTDIR"
    '';
}