#!/usr/bin/bash

set -o pipefail

ALHP_STATS_URL='https://api.alhp.dev/stats'
ALHP_BQ_URL='https://api.alhp.dev/packages?limit=0&offset=0&status=queued&status=building'

mirrorlistsOutOfDate(){
  local max_mirrors="${1:-1}"
  local mirrorlists mirrorlist mirror_urls mirror_url all_mirrors=() alhp_timestamp
  local -A mirror_timestamps=()

  readarray -t mirrorlists < <(awk '
      /^\s*\[.*x86-64-v[2-4].*\]/ { in_repo = 1; next }
      in_repo && /^\s*Include\s*=\s*/ {
        match($0, /Include\s*=\s*(.*)/, arr)
        print arr[1]
        in_repo = 0
      }
    ' /etc/pacman.conf | sort -u
  )

  for mirrorlist in ${mirrorlists[@]}; do
    readarray -t mirror_urls < <(
      grep '^Server =' "$mirrorlist" | \
      sed -E 's/^Server = (https?:\/\/[^$]+).*/\1\/lastupdate/'
    )
    all_mirrors+=(${mirror_urls[@]})
  done

  mapfile -t all_mirrors < <(printf '%s\n' ${all_mirrors[@]} | sort -u | head -n $max_mirrors)
  #TODO: fork curls for better performance
  for mirror_url in "${all_mirrors[@]}"; do
    # curl quietly, fail silently, timeout 5s
    timestamp=$(curl -fs --max-time 5 "$mirror_url" || echo "error")
    mirror_timestamps["$mirror_url"]=$timestamp
  done
  alhp_timestamp=$(curl -fs --max-time 5 $ALHP_STATS_URL | jq .last_mirror_timestamp || echo "error")

  for url in "${!mirror_timestamps[@]}"; do
    if [[ ${mirror_timestamps[$url]} -lt $alhp_timestamp ]]; then
      echo "Mirror: $url outdated."
    fi
  done
}

updatesAvailable() {
  readarray -t repos < <(grep '^\[' /etc/pacman.conf | sed -e 's/[][]//g' | grep -E 'x86-64-v[2-4]')

  output_json=false
  check_pkg=""
  
  while [[ $# -gt 0 ]]; do
    case "$1" in
      -j|--json) output_json=true; shift ;;
      --check-pkg)
        check_pkg=$2
        shift 2
        ;;
      *)
        echo "Unknown argument: $1"
        return 1
        ;;
    esac
  done

  declare -A pkgs

  while read -r _ name version status; do
    if [[ $status == *installed* ]]; then
      pkgs[$name]=1
    fi
  done < <(pacman -Sl ${repos[@]})

  repo_query=$(printf '&repo=%s' "${repos[@]}")
  api_url="$ALHP_BQ_URL${repo_query}"

  if [[ -n $check_pkg ]]; then
    building_pkgs=$(curl -s $api_url \
      | jq -r --arg pkg $check_pkg '.packages[] | select(.split_packages[] == $pkg) | .split_packages[]')

    matches=()
    for bpkg in $building_pkgs; do
      if [[ -n "${pkgs[$bpkg]}" ]]; then
        matches+=("$bpkg")
      fi
    done

    if $output_json; then
      printf '%s\n' "${matches[@]}" | jq -Rn '[inputs]'
    else
      printf '%s\n' "${matches[@]}"
    fi
  else
    matches=()
    while read -r pkgname; do
      if [[ -n ${pkgs[$pkgname]} ]]; then
        matches+=($pkgname)
      fi
    done < <(curl -s $api_url | jq -r '.packages[] | .split_packages[]')

    if $output_json; then
      printf '%s\n' ${matches[@]} | jq -Rn '[inputs]'
    else
      printf '%s\n' ${matches[@]}
    fi
  fi
}


mirrorlistsOutOfDate
updatesAvailable $@