#!/usr/bin/env nu

const HEADER = "
  ----- MEAT ----------------------------------------
"

const FOOTER = "
  ---------------------------------------------------
"

const HELP_TEXT = "
   YUM    -  CONSUME DELICIOUS MEATS
   COOK   -  ONLY PREPARE MEATS
   POKE   -  TASTE SUSPICIOUS MEATS
   GUT    -  CLEAN MEAT STORES
   FRESH  -  HUNT FRESH MEATS
   LOOK   -  LOOK FOR FRESHER MEATS
   HUNT   -  HUNT FOR MEATS IN NIXPKGS
   RITUAL -  PERFORM RITUAL THEN CONSUME
   TRADE  -  SEND MEATS FAR AWAY
   ..-A   -  ..ALL MEATS"

def meat-print [text: string] {
  print $"\n   \t($text)\n"
}

def with-frame [body: closure] {
  print -n $HEADER
  do $body
  print -n $FOOTER
}

def hn []: nothing -> string {
  ^hostname | str trim
}

def system-attr []: nothing -> string {
  $"nixosConfigurations.(hn).config.system.build.toplevel"
}

def nix-conf-attr []: nothing -> string {
  $"nixosConfigurations.(hn).config.environment.etc.\"nix/nix.conf\""
}

def nix-build-nom [out: string, build_args: list<string>] {
  if ($env.MONITOR? | is-empty) {
    ^nix-build --out-link $out ...$build_args
  } else {
    ^nix-build --log-format internal-json --out-link $out ...$build_args out+err>| ^$env.MONITOR --json
  }
  # Piping to MONITOR masks nix-build's exit code, so detect failure by the
  # absence of the out-link.
  if not ($out | path exists) {
    error make { msg: "nix-build produced no output" }
  }
}

def differ-step [build: string] {
  if ($env.DIFFER? | is-empty) {
    meat-print "  (no DIFFER set; skipping diff)"
  } else {
    ^$env.DIFFER /nix/var/nix/profiles/system $build
  }
}

def activate [build_path: string] {
  ^sudo $nu.current-exe -c $"nix-env --set -p /nix/var/nix/profiles/system ($build_path); ($build_path)/bin/switch-to-configuration switch"
}

def do-build [extras: list<string> = []] {
  let tmpdir = ^mktemp -d -t "meat-build.XXXXXX" | str trim
  let build = $"($tmpdir)/build"
  warm-pins
  let start = date now
  let drv = ^nix-instantiate $"($env.MEATS)/entry.nix" -A (system-attr) ...$extras | lines | last | str trim
  meat-print $"MASTICATION TAKING ((date now) - $start)"
  nix-build-nom $build [$drv]
  differ-step $build
  activate $build
  try { rm $build }
}

def cmd-help [] {
  print -n $"($HEADER)($HELP_TEXT)($FOOTER)\n"
}

def cmd-yum [...args: string] {
  with-frame {
    meat-print "CONSUMING DELICIOUS MEATS.."
    try { do-build $args } catch { print "FAILED TO CONSUME MEATS." }
  }
}

def cmd-cook [...args: string] {
  with-frame {
    meat-print "PREPARING DELICIOUS MEATS.."
    warm-pins
    try { ^nix-build --no-out-link $"($env.MEATS)/entry.nix" -A (system-attr) ...$args }
  }
}

def cmd-poke [...args: string] {
  with-frame {
    meat-print "PREPARING SUSPICIOUS MEATS.."
    warm-pins
    try { ^nix-build --no-out-link --show-trace $"($env.MEATS)/entry.nix" -A (system-attr) ...$args }
  }
}

def cmd-gut [...args: string] {
  with-frame {
    meat-print "CLEANING MEAT STORES.."
    try { ^nh clean all ...$args }
  }
}

def cmd-trade [] {
  with-frame {
    meat-print "TRADING FOREIGN MEATS.."
    meat-print "tbd"
  }
}

def lock-path [] { $"($env.MEATS)/.tack/pins.lock.json" }

def load-lock [] {
  let p = lock-path
  if ($p | path exists) { open --raw $p | from json } else { {} }
}

# Fetch one locked input into the store, mirroring the tack resolver's
# `builtins.fetchTree lock.<name>`. Returns the name on failure, else null.
def warm-pin [name: string, node: record] {
  let tmp = ^mktemp -t "meat-pin.XXXXXX.json" | str trim
  $node | to json | save -f $tmp
  let expr = $"\(builtins.fetchTree \(builtins.fromJSON \(builtins.readFile \"($tmp)\"\)\)\).outPath"
  let r = ^nix eval --impure --raw --expr $expr | complete
  try { rm $tmp }
  if $r.exit_code != 0 { $name } else { null }
}

# Pre-fetch every locked input in parallel so the serial fetchTree calls
# during evaluation become cache hits. Warming is idempotent and non-fatal:
# anything that fails here is simply re-fetched by the build itself.
def warm-pins [] {
  let lock = load-lock
  let names = $lock | columns
  if ($names | is-empty) { return }
  meat-print "GATHERING MEATS.."
  let failed = $names | par-each { |name| warm-pin $name ($lock | get $name) } | compact
  for name in $failed {
    meat-print $"  COULDN'T GATHER ($name | str upcase) \(BUILD WILL RETRY\)"
  }
}

def cmd-fresh [...names: string] {
  with-frame {
    meat-print "HUNTING FRESH MEATS.."
    do { cd $env.MEATS; ^$env.TACK update ...$names }
  }
}

def cmd-look [...names: string] {
  with-frame {
    meat-print "LOOK FOR NEW MEATS.."
    do { cd $env.MEATS; ^$env.TACK look ...$names }
  }
}

def truncate-desc [s: string, n: int]: nothing -> string {
  if (($s | str length) > $n) {
    ($s | str substring 0..$n) + ".."
  } else {
    $s
  }
}

def cmd-hunt [...query: string] {
  with-frame {
    if ($query | is-empty) {
      meat-print "WHAT MEAT YOU SEEK?"
      return
    }
    let q = $query | str join " "
    meat-print $"HUNTING FOR ($q | str upcase).."
    let body = {
      from: 0,
      size: 20,
      sort: [{ _score: "desc", package_attr_name: "desc", package_pversion: "desc" }],
      collapse: { field: "package_attr_name" },
      query: {
        bool: {
          must: [
            { term: { type: "package" } },
            { multi_match: {
                type: "cross_fields",
                query: $q,
                fields: ["package_attr_name^9", "package_pname^6", "package_description^1.3", "package_longDescription^1"]
            } }
          ]
        }
      }
    }
    try {
      let resp = (
        http post
          --user "aWVSALXpZv"
          --password "X8gPHnzL52wFEekuxsfQ9cSh"
          --content-type "application/json"
          "https://nixos-search-7-1733963800.us-east-1.bonsaisearch.net/nixos-*-unstable-*/_search"
          $body
      )
      let hits = $resp.hits?.hits? | default []
      if ($hits | is-empty) {
        meat-print "NO MEATS FOUND!"
      } else {
        for hit in $hits {
          let src = $hit._source
          let name = $src.package_attr_name? | default "?"
          let ver = $src.package_pversion? | default ""
          let desc = $src.package_description? | default ""
          let ver_str = if ($ver | is-empty) { "" } else { $" \(($ver)\)" }
          print $"   \tnixpkgs#($name)($ver_str)"
          if not ($desc | is-empty) {
            print $"   \t  (truncate-desc $desc 60)"
          }
        }
      }
    } catch { |e|
      meat-print $"HUNT FAILED: ($e.msg)"
    }
  }
}

def cmd-ritual [] {
  with-frame {
    meat-print "PREPARING RITUAL GROUND.."
    let tmpdir = ^mktemp -d -t "meat-chew.XXXXXX" | str trim
    let meats = $env.MEATS
    let nix_conf = $"($tmpdir)/nix.conf"
    let build = $"($tmpdir)/build"
    try {
      warm-pins
      nix-build-nom $nix_conf [$"($meats)/entry.nix" "-A" (nix-conf-attr)]
      meat-print "CONSUMING MEATS.."
      with-env { NIX_USER_CONF_FILES: $nix_conf } {
        nix-build-nom $build [$"($meats)/entry.nix" "-A" (system-attr)]
      }
      ^$env.DIFFER /nix/var/nix/profiles/system $build
      activate $build
      try { rm $nix_conf }
      try { rm $build }
    } catch {
      print "FAILED TO CONSUME MEATS."
    }
  }
}

def cmd-shelter [new_closure: string] {
  activate $new_closure
}

def main [...args: string] {
  if ($env.MEATS? | is-empty) {
    meat-print "NO PATH TO RUNESTONE FOUND!"
    cmd-help
    return
  }
  let sub = $args | get 0? | default "" | str downcase
  let rest = $args | skip 1
  match $sub {
    "yum" => { cmd-yum ...$rest }
    "cook" => { cmd-cook ...$rest }
    "poke" => { cmd-poke ...$rest }
    "gut" => { cmd-gut ...$rest }
    "trade" => { cmd-trade }
    "look" => { cmd-look ...$rest }
    "fresh" => { cmd-fresh ...$rest }
    "hunt" => { cmd-hunt ...$rest }
    "ritual" => { cmd-ritual }
    "shelter" => { cmd-shelter $rest }
    _ => { cmd-help }
  }
}