#!/usr/bin/env bash

# This script sets up API documentation bundles for deployment to Github Pages.
# It expects the following structure:
#
# In development branches:
#
#   * ./docs/openapi.yaml - OpenAPI spec in
#   * ./docs/gh-pages     - Any assets that should be copied to gh-pages root
#
# In Github Pages, it will generate:
#
#   * ./                      - Files from ./docs/gh-pages will be copied
#   * ./branches/<branch>/... - Deployment bundles including an index.html
#                               and a snapshot of the Open API spec.

set -eo pipefail

prepare_docs_log() {
  echo "[prepare docs release] -- $@"
}

# Only run for tagged commits
if [ -z "$(git tag -l --points-at HEAD)" ]; then
  prepare_docs_log "Skipping non-tagged commit."
  exit 0
fi

DOCS_DIR="./docs"
DIST_DIR="./dist/docs"
BRANCHES_DIR="${DIST_DIR}/branches"
API_SPEC_FILE="${DOCS_DIR}/openapi.yaml"

rm -rf "${DIST_DIR}"

redoc_bundle_file=$(mktemp)
git_ref_version=$(git describe --always)
branch_docs_dir="${BRANCHES_DIR}/${git_ref_version}"

# Build Redoc bundle (a single HTML file)
redoc-cli bundle ${API_SPEC_FILE} -o ${redoc_bundle_file} --title 'Milight Hub API Documentation'

# Check out current stuff from gh-pages (we'll append to it)
git fetch origin 'refs/heads/gh-pages:refs/heads/gh-pages'
git checkout gh-pages -- branches || prepare_docs_log "Failed to checkout branches from gh-pages, skipping..."

if [ -e "./branches" ]; then
  mkdir -p "${DIST_DIR}"
  mv "./branches" "${BRANCHES_DIR}"
else
  mkdir -p "${BRANCHES_DIR}"
fi

if [ -e "${DOCS_DIR}/gh-pages" ]; then
  cp -r ${DOCS_DIR}/gh-pages/* "${DIST_DIR}"
else
  prepare_docs_log "Skipping copy of gh-pages dir, doesn't exist"
fi

# Create the docs bundle for our ref.  This will be the redoc bundle + a
# snapshot of the OpenAPI spec
mkdir -p "${branch_docs_dir}"
cp "${API_SPEC_FILE}" "${branch_docs_dir}"
cp "${redoc_bundle_file}" "${branch_docs_dir}/index.html"

# Update `latest` symlink to this branch
rm -rf "${BRANCHES_DIR}/latest"
ln -s "${git_ref_version}" "${BRANCHES_DIR}/latest"

# Create a JSON file containing a list of all branches with docs (we'll
# have an index page that renders the list).
ls "${BRANCHES_DIR}" | jq -Rc '.' | jq -sc '.' > "${DIST_DIR}/branches.json"