#!/usr/bin/env sh
set -eu

ROOT_DIR=$(CDPATH= cd -- "$(dirname -- "$0")/.." && pwd)
cd "$ROOT_DIR"

ABOUT_FILE="$ROOT_DIR/iti/__about__.py"
COPIER_FILE="$ROOT_DIR/copier.yml"
COPIER_TEMPLATE_FILE="$ROOT_DIR/copier-template/pyproject.toml.jinja"
README_FILE="$ROOT_DIR/README.md"

die() {
  printf '%s\n' "$*" >&2
  exit 1
}

parse_version() {
  raw=$1
  version=${raw#v}
  old_ifs=$IFS
  IFS=.
  set -- $version
  IFS=$old_ifs

  if [ "$#" -ne 3 ]; then
    die "invalid version: $raw"
  fi

  for part in "$@"; do
    case $part in
      ''|*[!0-9]*)
        die "invalid version: $raw"
        ;;
    esac
  done

  printf '%s %s %s\n' "$1" "$2" "$3"
}

normalize_version() {
  set -- $(parse_version "$1")
  printf '%s.%s.%s\n' "$1" "$2" "$3"
}

bump_patch() {
  set -- $(parse_version "$1")
  printf '%s.%s.%s\n' "$1" "$2" "$(( $3 + 1 ))"
}

version_is_newer() {
  current_version=$1
  target_version=$2

  current_parts=$(parse_version "$current_version")
  set -- $current_parts
  current_major=$1
  current_minor=$2
  current_patch=$3

  target_parts=$(parse_version "$target_version")
  set -- $target_parts
  target_major=$1
  target_minor=$2
  target_patch=$3

  if [ "$target_major" -gt "$current_major" ]; then
    return 0
  fi
  if [ "$target_major" -lt "$current_major" ]; then
    return 1
  fi
  if [ "$target_minor" -gt "$current_minor" ]; then
    return 0
  fi
  if [ "$target_minor" -lt "$current_minor" ]; then
    return 1
  fi
  [ "$target_patch" -gt "$current_patch" ]
}

read_current_version() {
  current_version=$(sed -n 's/^__version__[[:space:]]*=[[:space:]]*"\([^"]*\)".*$/\1/p' "$ABOUT_FILE" | sed -n '1p')
  [ -n "$current_version" ] || die "version not found in $ABOUT_FILE"
  printf '%s\n' "$current_version"
}

replace_first_line_with_prefix() {
  file=$1
  prefix=$2
  new_line=$3
  tmp_file=$(mktemp)

  if awk -v prefix="$prefix" -v new="$new_line" '
    BEGIN { done = 0 }
    index($0, prefix) == 1 && !done {
      print new
      done = 1
      next
    }
    { print }
    END { if (!done) exit 1 }
  ' "$file" >"$tmp_file"; then
    mv "$tmp_file" "$file"
  else
    rm -f "$tmp_file"
    die "line not updated in $file"
  fi
}

replace_first_line_in_section_with_prefix() {
  file=$1
  section_header=$2
  prefix=$3
  new_line=$4
  tmp_file=$(mktemp)

  if awk -v section="$section_header" -v prefix="$prefix" -v new="$new_line" '
    BEGIN { in_section = 0; done = 0 }
    $0 == section { in_section = 1; print; next }
    in_section && /^[^[:space:]]/ { in_section = 0 }
    in_section && !done && index($0, prefix) == 1 {
      print new
      done = 1
      next
    }
    { print }
    END { if (!done) exit 1 }
  ' "$file" >"$tmp_file"; then
    mv "$tmp_file" "$file"
  else
    rm -f "$tmp_file"
    die "line not updated in $file"
  fi
}

write_about_version() {
  target_version=$1
  replace_first_line_with_prefix "$ABOUT_FILE" "__version__ = " "__version__ = \"$target_version\""
}

write_copier_framework_tag() {
  target_version=$1
  replace_first_line_in_section_with_prefix "$COPIER_FILE" "framework_tag:" "  default: v" "  default: v$target_version"
}

write_copier_system_tag() {
  target_version=$1
  replace_first_line_in_section_with_prefix "$COPIER_FILE" "system_tag:" "  default: v" "  default: v$target_version"
}

write_copier_template_version() {
  target_version=$1
  replace_first_line_with_prefix "$COPIER_TEMPLATE_FILE" "version = " "version = \"$target_version\""
}

write_readme_dependency_tag() {
  target_version=$1
  replace_first_line_with_prefix "$README_FILE" '  "iti-flask @ git+https://git.noahlan.cn/iti-framework/iTi-Flask.git@v' '  "iti-flask @ git+https://git.noahlan.cn/iti-framework/iTi-Flask.git@v'"$target_version"'",'
}

write_readme_release_examples() {
  target_version=$1
  replace_first_line_with_prefix "$README_FILE" './iti.sh release v' "./iti.sh release v$target_version"
  replace_first_line_with_prefix "$README_FILE" 'iti.cmd release v' "iti.cmd release v$target_version"
}

ensure_clean_tree() {
  if [ -n "$(git status --porcelain)" ]; then
    die "working tree is not clean"
  fi
}

ensure_branch() {
  if branch=$(git symbolic-ref --quiet --short HEAD 2>/dev/null); then
    [ -n "$branch" ] || die "release requires a branch checkout"
    printf '%s\n' "$branch"
  else
    die "release requires a branch checkout"
  fi
}

ensure_tag_absent() {
  tag=$1
  if git rev-parse --verify --quiet "refs/tags/$tag" >/dev/null; then
    die "tag already exists: $tag"
  fi
}

main() {
  version_arg=${1:-}
  current_version=$(read_current_version)
  if [ -n "$version_arg" ]; then
    target_version=$(normalize_version "$version_arg")
  else
    target_version=$(bump_patch "$current_version")
  fi
  target_tag="v$target_version"

  if [ "$target_version" = "$current_version" ]; then
    die "version already set to $target_version"
  fi
  if ! version_is_newer "$current_version" "$target_version"; then
    die "target version must be newer than $current_version"
  fi

  ensure_clean_tree
  branch=$(ensure_branch)
  ensure_tag_absent "$target_tag"
  uv run pytest -q

  write_about_version "$target_version"
  write_copier_framework_tag "$target_version"
  write_copier_system_tag "$target_version"
  write_copier_template_version "$target_version"
  write_readme_dependency_tag "$target_version"
  write_readme_release_examples "$target_version"

  git add iti/__about__.py copier.yml copier-template/pyproject.toml.jinja README.md
  git commit -m "chore: release $target_tag"
  git tag -a "$target_tag" -m "release $target_tag"
  git push origin "$branch" "$target_tag"

  printf 'released %s\n' "$target_tag"
}

main "$@"