#!/bin/sh
#
# This script does not have a stable API.

_gitstatus_install_main() {
  if [ -n "${ZSH_VERSION:-}" ]; then
    emulate -L sh -o no_unset
  else
    set -u
  fi

  local argv1=$1
  shift

  local no_check= no_install= uname_s= uname_m= gitstatus_dir= dl_status=
  local opt= OPTARG= OPTIND=1

  while getopts ':s:m:d:p:fnh' opt "$@"; do
    case "$opt" in
      h)
        command cat <<\END
Usage: install [-s KERNEL] [-m ARCH] [-d DIR] [-p CMD] [-f|-n] [-- CMD [ARG]...]

If positional arguments are specified, call this on success:

  CMD [ARG]... DAEMON VERSION INSTALLED

DAEMON is path to gitstatusd. VERSION is a glob pattern for the
version this daemon should support; it's supposed to be passed as
-G to gitstatusd. INSTALLED is 1 if gitstatusd has just been
downloaded and 0 otherwise.

Options:

  -s KERNEL  use this instead of lowercase `uname -s`
  -m ARCH    use this instead of lowercase `uname -m`
  -d DIR     use this instead of `dirname "$0"`
  -p CMD     eval this every second while downloading gitstatusd
  -f         download gitstatusd even if there is one locally
  -n         do not download gitstatusd (fail instead)
END
        return
      ;;
      n)
        if [ -n "$no_install" ]; then
          >&2 echo "[gitstatus] error: duplicate option: -$opt"
          return 1
        fi
        no_install=1
      ;;
      f)
        if [ -n "$no_check" ]; then
          >&2 echo "[gitstatus] error: duplicate option: -$opt"
          return 1
        fi
        no_check=1
      ;;
      d)
        if [ -n "$gitstatus_dir" ]; then
          >&2 echo "[gitstatus] error: duplicate option: -$opt"
          return 1
        fi
        if [ -z "$OPTARG" ]; then
          >&2 echo "[error] incorrect value of -$opt: $OPTARG"
          return 1
        fi
        gitstatus_dir="$OPTARG"
      ;;
      p)
        if [ -n "$dl_status" ]; then
          >&2 echo "[gitstatus] error: duplicate option: -$opt"
          return 1
        fi
        if [ -z "$OPTARG" ]; then
          >&2 echo "[error] incorrect value of -$opt: $OPTARG"
          return 1
        fi
        dl_status="$OPTARG"
      ;;
      m)
        if [ -n "$uname_m" ]; then
          >&2 echo "[gitstatus] error: duplicate option: -$opt"
          return 1
        fi
        if [ -z "$OPTARG" ]; then
          >&2 echo "[error] incorrect value of -$opt: $OPTARG"
          return 1
        fi
        uname_m="$OPTARG"
      ;;
      s)
        if [ -n "$uname_s" ]; then
          >&2 echo "[gitstatus] error: duplicate option: -$opt"
          return 1
        fi
        if [ -z "$OPTARG" ]; then
          >&2 echo "[error] incorrect value of -$opt: $OPTARG"
          return 1
        fi
        uname_s="$OPTARG"
      ;;
      \?) >&2 echo "[gitstatus] error: invalid option: -$OPTARG"           ; return 1;;
      :)  >&2 echo "[gitstatus] error: missing required argument: -$OPTARG"; return 1;;
      *)  >&2 echo "[gitstatus] internal error: unhandled option: -$opt"   ; return 1;;
    esac
  done

  shift "$((OPTIND - 1))"

  : "${gitstatus_dir:=$argv1}"

  if [ -n "$no_check" -a -n "$no_install" ]; then
    >&2 echo "[gitstatus] error: incompatible options: -f, -n"
    return 1
  fi

  if [ -z "$uname_s" ]; then
    uname_s="$(command uname -s)" || return
    uname_s="$(printf '%s' "$uname_s" | command tr '[A-Z]' '[a-z]')" || return
  fi
  if [ -z "$uname_m" ]; then
    uname_m="$(command uname -m)" || return
    uname_m="$(printf '%s' "$uname_m" | command tr '[A-Z]' '[a-z]')" || return
  fi

  local daemon="${GITSTATUS_DAEMON:-}"
  local cache_dir="${GITSTATUS_CACHE_DIR:-${XDG_CACHE_HOME:-$HOME/.cache}/gitstatus}"

  if [ -z "$no_check" ]; then
    if [ -n "${daemon##/*}" ]; then
      >&2 echo "[gitstatus] error: GITSTATUS_DAEMON is not absolute path: $daemon"
      return 1
    fi
    if [ -z "$daemon" ]; then
      daemon="$gitstatus_dir"/usrbin/gitstatusd
      if [ ! -e "$daemon" ]; then
        daemon="$daemon"-"$uname_s"-"$uname_m"
        if [ ! -e "$daemon" ]; then
          daemon=
        fi
      fi
    fi
    if [ -n "$daemon" ]; then
      local gitstatus_version= libgit2_version=
      if ! . "$gitstatus_dir"/build.info; then
        >&2 echo "[gitstatus] internal error: failed to source build.info"
        return 1
      fi
      if [ -z "$gitstatus_version" ]; then
        >&2 echo "[gitstatus] internal error: empty gitstatus_version in build.info"
        return 1
      fi
      [ $# = 0 ] || "$@" "$daemon" "$gitstatus_version" 0
      return
    fi
  fi

  while IFS= read -r line; do
    line="${line###*}"
    [ -n "$line" ] || continue

    local uname_s_glob= uname_m_glob= file= version=
    eval "$line" || return

    if [ -z "$uname_s_glob" -o -z "$uname_m_glob" -o -z "$file" -o -z "$version" ]; then
      >&2 echo "[gitstatus] internal error: invalid install.info line: $line"
      return 1
    fi

    case "$uname_s" in
      $uname_s_glob) ;;
      *) continue;;
    esac
    case "$uname_m" in
      $uname_m_glob) ;;
      *) continue;;
    esac

    # Found a match. The while loop will terminate during this iteration.

    if [ -z "$no_check" ]; then
      # Check if a suitable gitstatusd already exists.
      local daemon="$cache_dir"/"$file"
      if [ -e "$daemon" ]; then
        [ $# = 0 ] || "$@" "$daemon" "$version" 0
        return
      fi
      daemon="$daemon"-"$uname_s"-"$uname_m"
      if [ -e "$daemon" ]; then
        local gitstatus_version= libgit2_version=
        if ! . "$gitstatus_dir"/build.info; then
          >&2 echo "[gitstatus] internal error: failed to source build.info"
          return 1
        fi
        if [ -z "$gitstatus_version" ]; then
          >&2 echo "[gitstatus] internal error: empty gitstatus_version in build.info"
          return 1
        fi
        [ $# = 0 ] || "$@" "$daemon" "$gitstatus_version" 0
        return
      fi
    fi

    # No suitable gitstatusd exists. Need to download.

    if [ -n "$no_install" ]; then
      >&2 echo "[gitstatus] error: no gitstatusd found and installation is disabled"
      return 1
    fi

    local daemon="$cache_dir"/"$file"

    if [ -n "${cache_dir##/*}" ]; then
      >&2 echo "[gitstatus] error: GITSTATUS_CACHE_DIR is not absolute: $cache_dir"
      return 1
    fi
    [ -d "$cache_dir" ] || mkdir -p -- "$cache_dir" || return

    (
      local fetch
      if command -v curl >/dev/null 2>&1; then
        fetch="command curl -fsSLo"
      elif command -v wget >/dev/null 2>&1; then
        fetch="command wget -O"
      else
        >&2 echo "[gitstatus] error: please install curl or wget"
        exit 1
      fi

      local url1="https://github.com/romkatv/gitstatus/releases/download/$version/$file.tar.gz"
      local url2="https://gitee.com/romkatv/gitstatus/raw/release-$version/release/$file.tar.gz"
      local tmp="$file".tmp.$$

      if [ -n "${ZSH_VERSION:-}" ]; then
        builtin cd -q -- "$cache_dir" || exit
      else
        cd -- "$cache_dir" || exit
      fi

      cleanup() {
        local n
        for n in "$@"; do
          command rm -rf -- "$tmp"."$n".tar.gz "$tmp"."$n".status || return
        done
      }

      local sig='INT QUIT TERM ILL PIPE'

      fetch() {
        local trapped=
        trap 'trapped=1' $sig
        # TODO: enable this after adding sha256 verification.
        [ "$1" = 1 ] || return
        if [ "$1" != 1 ] && command -v sleep >/dev/null 2>/dev/null; then
          sleep "$1"
        fi
        $fetch "$tmp"."$1".tar.gz -- "$2" 2>/dev/null &
        local pid=$!
        local die="trap - $sig; kill -- $pid 2>/dev/null; cleanup $1; exit 1"
        trap "$die" $sig
        [ -z "$trapped" ] || eval "$die"
        wait -- "$pid" 2>/dev/null
        local ret="$?"
        echo -n >"$tmp"."$1".status
        trap - $sig
        return "$ret"
      }

      local trapped=
      trap 'trapped=1' $sig
      fetch 1 "$url1" & 
      local pid1=$!
      fetch 2 "$url2" & 
      local pid2=$!

      local die="trap - $sig; kill -- $pid1 $pid2 2>/dev/null; cleanup 1 2; exit 1"
      trap "$die" $sig
      [ -z "$trapped" ] || eval "$die"

      local n=
      while true; do
        [ -z "$dl_status" ] || eval "$dl_status" || eval "$die"
        if command -v sleep >/dev/null 2>/dev/null; then
          command sleep 1
        elif command -v true >/dev/null 2>/dev/null; then
          command true
        fi
        if [ -n "$pid1" -a -e "$tmp".1.status ]; then
          wait -- "$pid1" 2>/dev/null
          local ret="$?"
          pid1=
          if [ "$ret" = 0 ]; then
            [ -z "$pid2" ] || kill -- "$pid2" 2>/dev/null
            n=1
            break
          elif [ -z "$pid2" ]; then
            break
          fi
        elif [ -n "$pid2" -a -e "$tmp".2.status ]; then
          wait -- "$pid2" 2>/dev/null
          local ret="$?"
          pid2=
          if [ "$ret" = 0 ]; then
            [ -z "$pid1" ] || kill -- "$pid1" 2>/dev/null
            n=2
            break
          elif [ -z "$pid1" ]; then
            break
          fi
        fi
      done

      trap - $sig

      if [ -z "$n" ]; then
        >&2 echo "[gitstatus] error: failed to download gitstatusd from any mirror"
        >&2 echo ""
        >&2 echo "  1. $url1"
        >&2 echo "  2. $url2"
        cleanup 1 2
        exit 1
      fi

      local old=
      if [ -e "$daemon" ]; then
        local i=1
        while :; do
          old="$daemon"."$i"
          [ -e "$old" ] || break
          i="$((i+1))"
        done
        if ! command mv -f -- "$daemon" "$old"; then
          cleanup 1 2
          exit 1
        fi
      fi

      command tar -xzf "$tmp"."$n".tar.gz
      local ret=$?
      cleanup 1 2
      if [ -n "$old" ]; then
        if [ "$ret" = 0 ]; then
          command rm -f -- "$old" 2>/dev/null
        else
          command mv -f -- "$old" "$daemon"
        fi
      fi
      exit "$ret"
    ) || return

    [ $# = 0 ] || "$@" "$daemon" "$version" 1
    return
  done <"$gitstatus_dir"/install.info

  >&2 echo "[gitstatus] error: no gitstatusd found for $uname_s $uname_m"
  return 1
}

if [ -z "${0##*/*}" ]; then
  _gitstatus_install_main "${0%/*}" "$@"
else
  _gitstatus_install_main . "$@"
fi