#!/usr/bin/env bash
#
# Summary: Install a published binary package
#
# Usage: pyenv binary install <version>
#
#   Selects a compatible package from pyenv.github.io and installs it under
#   <version>. Ordinary `pyenv install' is unchanged.
#
set -e
[ -n "$PYENV_DEBUG" ] && set -x

if [ "$1" = "--complete" ]; then
  exit
fi

if [ "$#" -ne 1 ]; then
  pyenv-help --usage binary-install >&2
  exit 1
fi

case "$1" in
*/* | .. | . | *[[:cntrl:]]* )
  echo "pyenv-binary: invalid version name \`$1'" >&2
  exit 1
  ;;
esac

requested="$1"
os="$(uname -s)"
arch="$(uname -m)"

case "$os" in
Linux )
  if [ -r /etc/os-release ]; then
    distro="$(. /etc/os-release && printf '%s %s' "${ID:-}" "${VERSION_ID:-}")"
  elif type -p lsb_release >/dev/null; then
    distro="$(lsb_release -si) $(lsb_release -sr)"
  fi
  distro="$(printf '%s' "$distro" | tr '[:upper:]' '[:lower:]')"
  ;;
Darwin )
  distro="macos $(sw_vers -productVersion)"
  ;;
esac

tmpdir="$(mktemp -d)"
trap 'rm -rf "$tmpdir"' EXIT
base_url="https://pyenv.github.io/pythons/binaries"
manifest_dir="$(dirname "${BASH_SOURCE[0]}")/../share/pyenv-binary/versions"
case "$requested" in
*.*.* ) manifests=( "$manifest_dir/${requested%.*}" ) ;;
*.* ) manifests=( "$manifest_dir/$requested" ) ;;
* ) manifests=( "$manifest_dir/$requested".* ) ;;
esac

matches="$tmpdir/matches"
: > "$matches"
for manifest in "${manifests[@]}"; do
  [ -f "$manifest" ] || continue
  while IFS=$'\t' read -r source_version name target_os target_arch target_distro sha256; do
    case "$source_version" in
    "$requested" | "$requested".* ) ;;
    * ) continue ;;
    esac
    [[ "$source_version" =~ ^[0-9]+(\.[0-9]+){1,2}$ ]] || continue
    [ "$target_os" = "$os" ] && [ "$target_arch" = "$arch" ] || continue
    case "$name" in
    "" | . | .. | *[!A-Za-z0-9._-]* ) continue ;;
    esac
    case "$os" in
    Linux ) [ "$(printf '%s' "$target_distro" | tr '[:upper:]' '[:lower:]')" = "$distro" ] || continue ;;
    Darwin )
      target_version="${target_distro#macos }"
      [ "$target_version" != "$target_distro" ] || continue
      host_version="${distro#macos }"
      [[ "$target_version" =~ ^[0-9]+(\.[0-9]+){1,2}$ ]] || continue
      [[ "$host_version" =~ ^[0-9]+(\.[0-9]+){1,2}$ ]] || continue
      IFS=. read -r target_major target_minor target_patch <<< "$target_version"
      IFS=. read -r host_major host_minor host_patch <<< "$host_version"
      target_patch="${target_patch:-0}"
      host_patch="${host_patch:-0}"
      [ "$host_major" -ge "$target_major" ] || continue
      if [ "$host_major" -eq "$target_major" ]; then
        [ "$host_minor" -ge "$target_minor" ] || continue
        if [ "$host_minor" -eq "$target_minor" ]; then
          [ "$host_patch" -ge "$target_patch" ] || continue
        fi
      fi
      ;;
    * ) continue ;;
    esac
    printf '%s\t%s\t%s\n' "$source_version" "$name" "$sha256" >> "$matches"
  done < "$manifest"
done

selection="$(sort -t. -k1,1nr -k2,2nr -k3,3nr "$matches" | head -n1)"
IFS=$'\t' read -r version entry expected_sha <<< "$selection"
if [ -z "$entry" ]; then
  echo "pyenv-binary: no binary available for $requested on $os/$arch" >&2
  exit 1
fi
definitions="$(pyenv-install --list --bare)" || definitions=""
if printf '%s\n' "$definitions" | grep -qxF -- "$entry"; then
  pyenv-install "$entry:$version"
  exit
fi

if ! [[ "$expected_sha" =~ ^[0-9a-fA-F]{64}$ ]]; then
  echo "pyenv-binary: invalid checksum for $entry" >&2
  exit 1
fi
expected_sha="$(printf '%s' "$expected_sha" | tr '[:upper:]' '[:lower:]')"

curl -fsSL -o "$tmpdir/$entry" "$base_url/$entry"
if command -v sha256sum >/dev/null 2>&1; then
  actual_sha="$(sha256sum "$tmpdir/$entry")"; actual_sha="${actual_sha%% *}"
elif command -v shasum >/dev/null 2>&1; then
  actual_sha="$(shasum -a 256 "$tmpdir/$entry")"; actual_sha="${actual_sha%% *}"
elif command -v openssl >/dev/null 2>&1; then
  actual_sha="$(openssl dgst -sha256 "$tmpdir/$entry")"; actual_sha="${actual_sha##* }"
else
  echo "pyenv-binary: need sha256sum, shasum or openssl to verify $entry" >&2
  exit 1
fi
if [ "$actual_sha" != "$expected_sha" ]; then
  echo "pyenv-binary: checksum mismatch for $entry" >&2
  exit 1
fi
pyenv-install "$tmpdir/$entry:$version"