#!/usr/bin/env bash

set -euo pipefail

usage() {
  echo "Usage: scripts/release X.Y.Z" >&2
  echo "Set RELEASE_DATE=YYYY-MM-DD to override the changelog/CITATION date." >&2
}

die() {
  echo "release: $*" >&2
  exit 1
}

require_clean_tracked_tree() {
  git diff --quiet || die "tracked worktree changes are present"
  git diff --cached --quiet || die "staged changes are present"
}

release_branch() {
  local version="$1"
  local branch="release-${version}"
  local current_branch

  current_branch="$(git branch --show-current || true)"
  if [[ "$current_branch" == "$branch" ]]; then
    return
  fi
  if git show-ref --verify --quiet "refs/heads/${branch}"; then
    die "branch ${branch} already exists; switch to it or delete it first"
  fi
  git switch -c "$branch"
}

require_match() {
  local pattern="$1"
  local path="$2"

  grep -qE "$pattern" "$path" || die "${path} does not match ${pattern}"
}

replace_required() {
  local pattern="$1"
  local replacement="$2"
  local path="$3"

  require_match "$pattern" "$path"
  sed -i -E "s#${pattern}#${replacement}#" "$path"
}

release_update_file() {
  local extname="$1"
  local update_dir="$2"
  local cmake_file="$3"
  local version="$4"
  local matches old_file new_file old_name new_name

  shopt -s nullglob
  matches=("${update_dir}/${extname}--"*--unreleased.sql)
  shopt -u nullglob

  if [[ ${#matches[@]} -ne 1 ]]; then
    die "expected exactly one ${update_dir}/${extname}--*--unreleased.sql, found ${#matches[@]}"
  fi

  old_file="${matches[0]}"
  new_file="${old_file/--unreleased.sql/--${version}.sql}"
  old_name="$(basename "$old_file")"
  new_name="$(basename "$new_file")"

  [[ "$old_file" != "$new_file" ]] || die "refusing to rename ${old_file} to itself"
  [[ ! -e "$new_file" ]] || die "${new_file} already exists"

  git mv "$old_file" "$new_file"
  sed -i "s/unreleased/${version}/g" "$new_file"
  sed -i -E 's/[[:space:]]+$//' "$new_file"
  grep -qF "$old_name" "$cmake_file" || die "${cmake_file} does not reference ${old_name}"
  OLD_NAME="$old_name" NEW_NAME="$new_name" \
    perl -0pi -e 's/\Q$ENV{OLD_NAME}\E/$ENV{NEW_NAME}/g' "$cmake_file"
}

changelog_previous_version() {
  sed -nE 's#^\[unreleased\]: .*/compare/v([0-9]+\.[0-9]+\.[0-9]+)\.\.\.HEAD$#\1#p' CHANGELOG.md
}

require_changelog_release_ready() {
  local version="$1"
  local previous_version

  previous_version="$(changelog_previous_version)"
  [[ -n "$previous_version" ]] || die "could not determine previous version from CHANGELOG.md [unreleased] link"
  if grep -qF "## [${version}]" CHANGELOG.md || grep -qF "[${version}]:" CHANGELOG.md; then
    die "CHANGELOG.md already has a [${version}] release entry"
  fi
}

update_changelog() {
  local version="$1"
  local release_date="$2"
  local previous_version tmp

  require_changelog_release_ready "$version"
  previous_version="$(changelog_previous_version)"

  tmp="$(mktemp)"
  awk -v version="$version" -v release_date="$release_date" '
    BEGIN { released = 0; in_release = 0; skip_summary = 0 }
    !released && $0 == "## [Unreleased]" {
      print "## [Unreleased]"
      print ""
      print "## [" version "] - " release_date
      released = 1
      in_release = 1
      next
    }
    in_release && $0 ~ /^[[:space:]]*<details>[[:space:]]*$/ {
      skip_summary = 1
      next
    }
    skip_summary {
      if ($0 ~ /^[[:space:]]*<\/summary>[[:space:]]*$/)
        skip_summary = 0
      next
    }
    in_release && $0 ~ /^[[:space:]]*<\/details>[[:space:]]*$/ {
      next
    }
    in_release && $0 ~ /^## \[/ {
      in_release = 0
    }
    { print }
  ' CHANGELOG.md > "$tmp"
  mv "$tmp" CHANGELOG.md

  tmp="$(mktemp)"
  awk -v version="$version" -v previous="v${previous_version}" '
    /^\[unreleased\]: / {
      print "[unreleased]: https://github.com/postgis/h3-pg/compare/v" version "...HEAD"
      print "[" version "]: https://github.com/postgis/h3-pg/compare/" previous "...v" version
      next
    }
    { print }
  ' CHANGELOG.md > "$tmp"
  mv "$tmp" CHANGELOG.md
}

verify_update_references() {
  local cmake_file update_path

  for cmake_file in h3/CMakeLists.txt h3_postgis/CMakeLists.txt; do
    while IFS= read -r update_path; do
      [[ -f "$(dirname "$cmake_file")/${update_path}" ]] ||
        die "${cmake_file} references missing ${update_path}"
    done < <(grep -oE 'sql/updates/[A-Za-z0-9_.-]+\.sql' "$cmake_file")
  done
}

verify_release_state() {
  local version="$1"

  verify_update_references

  if find h3/sql/updates h3_postgis/sql/updates -name '*--unreleased.sql' | grep -q .; then
    find h3/sql/updates h3_postgis/sql/updates -name '*--unreleased.sql' >&2
    die "unreleased update files remain after release"
  fi

  if grep -R -n -E 'availability: unreleased|Since vunreleased|UPDATE TO '\''unreleased'\''|--unreleased\.sql' \
      h3 h3_postgis docs/api.md CMakeLists.txt; then
    die "unreleased release markers remain"
  fi

  grep -q "VERSION ${version}" CMakeLists.txt || die "CMakeLists.txt project version was not updated"
  grep -q "set(INSTALL_VERSION \"\${PROJECT_VERSION}\")" CMakeLists.txt ||
    die "INSTALL_VERSION is not set to PROJECT_VERSION"

  scripts/check-metadata
  git diff --check
}

main() {
  [[ $# -eq 1 ]] || { usage; exit 2; }

  local version="$1"
  local release_date="${RELEASE_DATE:-$(date +%F)}"
  local repo_root h3_core_version

  [[ "$version" =~ ^[0-9]+\.[0-9]+\.[0-9]+$ ]] || die "version must be X.Y.Z"
  [[ "$release_date" =~ ^[0-9]{4}-[0-9]{2}-[0-9]{2}$ ]] ||
    die "RELEASE_DATE must be YYYY-MM-DD"

  repo_root="$(git rev-parse --show-toplevel)"
  cd "$repo_root"

  h3_core_version="$(sed -rnE 's/^set\(H3_CORE_VERSION ([0-9]+\.[0-9]+\.[0-9]+)\)/\1/p' CMakeLists.txt)"
  [[ -n "$h3_core_version" ]] || die "could not parse H3_CORE_VERSION"
  [[ "${version%.*}" == "${h3_core_version%.*}" ]] ||
    die "h3-pg major.minor (${version%.*}) must match H3 core major.minor (${h3_core_version%.*})"

  require_changelog_release_ready "$version"
  require_clean_tracked_tree
  release_branch "$version"

  replace_required '  VERSION [0-9]+\.[0-9]+\.[0-9]+' "  VERSION ${version}" CMakeLists.txt
  sed -i "/set(INSTALL_VERSION \"\${PROJECT_VERSION}\")/s/^#//g" CMakeLists.txt
  sed -i '/set(INSTALL_VERSION "unreleased")/s/^/#/g' CMakeLists.txt

  sed -i "s/availability: unreleased/availability: ${version}/g" h3/sql/install/*.sql
  sed -i "s/availability: unreleased/availability: ${version}/g" h3_postgis/sql/install/*.sql

  release_update_file h3 h3/sql/updates h3/CMakeLists.txt "$version"
  release_update_file h3_postgis h3_postgis/sql/updates h3_postgis/CMakeLists.txt "$version"

  sed -i "s/ALTER EXTENSION h3 UPDATE TO 'unreleased'/ALTER EXTENSION h3 UPDATE TO '${version}'/g" \
    h3/test/sql/extension.sql h3/test/expected/extension.out

  sed -i -E "s/^version: v[0-9]+\.[0-9]+\.[0-9]+/version: v${version}/" CITATION.cff
  sed -i -E "s/^date-released: [0-9]{4}-[0-9]{2}-[0-9]{2}/date-released: ${release_date}/" CITATION.cff

  update_changelog "$version" "$release_date"

  scripts/documentation
  verify_release_state "$version"

  echo "Release branch release-${version} is prepared."
  echo "Next:"
  echo "  - review and commit the release-${version} changes"
  echo "  - push and merge the release branch"
  echo "  - have the release manager publish GitHub release v${version} from CHANGELOG.md"
  echo "  - run scripts/bundle and upload to PGXN"
  echo "  - run scripts/postrelease after the release is merged"
}

main "$@"