#!/bin/bash -e
#
# Copyright 2018-present The Material Components for iOS Authors. All Rights Reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

usage() {
  echo "Usage: $0 <ComponentName>"
  echo
  echo "Generates a root readme file from a component's documentation."
  echo
  echo "Example usage: $0 ActivityIndicator"
}

if [ "$#" -ne 1 ]; then
  usage
  exit 1
fi

command -v jazzy >/dev/null 2>&1 || { 
  echo >&2 "Cannot find jazzy. jazzy is required to generate API links. To install try:"
  echo >&2 "[sudo] gem install jazzy"
  exit 1
}

# Generates a list of urls to APIs
# Args: $1 - Jazzy API type name. E.g. Classes
#       $2 - Docs API type name. E.g. Class
extract_apis_of_type() {
  type="$1"
  type_name="$2"
  cat apidocs/search.json | tr , '\n' \
      | grep "^\"$type" \
      | grep -v "$type\"$" \
      | grep -v "(.*).*(.*)" \
      | grep -v "/.*/" \
      | grep -v "@" \
      | sort | uniq \
      | while read line; do
    url=$(echo "$line" | cut -d'"' -f2)
    api=$(echo "$line" | cut -d'"' -f6)
    echo "* $type_name: [$api](${SITE_URL_BASE}${COMPONENT_SITE_PATH}/api-docs/$url)"
  done
}

COMPONENT="$1"

COMPONENT_PATH="components/$COMPONENT"
SITE_README_PATH="$COMPONENT_PATH/README.md"

mkdir -p $(dirname "$SITE_README_PATH")

TMP_PATH=$(mktemp -d)
TMP_README_PATH="$TMP_PATH/README.md"
TMP_EXPANDED_README_PATH="$TMP_PATH/README.md.expanded"
TMP_TOC_PATH="$TMP_PATH/toc.md"
TOC_STRING="<!-- toc -->"
DESIGN_AND_API_STRING="<!-- design-and-api -->"
BADGES_STRING="<!-- badges -->"
VARS_PATH="$COMPONENT_PATH/.vars"
JAZZY_PATH="$COMPONENT_PATH/.jazzy.yaml"
SITE_URL_BASE="https://material.io/components/ios"

touch "$TMP_README_PATH"

if [ ! -f "$VARS_PATH" ]; then
  echo "No .vars file found at $VARS_PATH. Please create one."
  exit 1
fi

if [ ! -f "$JAZZY_PATH" ]; then
  echo "No .jazzy.yaml file found at $JAZZY_PATH. Please create one. Note: it's .yaml - not .yml."
  exit 1
fi

echo "Generating template readme..."
if [[ $(grep -e "^root_path=" "$VARS_PATH") ]]; then
  ./scripts/apply_template "$COMPONENT" scripts/templates/component/README.md.template "$TMP_README_PATH" >> /dev/null
  COMPONENT_SITE_PATH=$(grep -e "^root_path=" "$VARS_PATH" | cut -d'=' -f2-)
fi

COMPONENT_NAME=$(grep -e "^component=" "$VARS_PATH" | cut -d'=' -f2-)

echo "<!-- This file was auto-generated using $0 $COMPONENT -->" >> "$TMP_README_PATH"
echo "" >> "$TMP_README_PATH"

cat "$COMPONENT_PATH/docs/README.md" >> "$TMP_README_PATH"

echo "Expanding all articles inline..."

# Expand all files inline
IFS='' # Don't trim whitespace from lines
cat "$TMP_README_PATH" | while read line; do
  if [[ $(echo $line | grep -e "^- \[.*\]\(.*\)$") ]]; then
    file=$(echo $line | cut -d'(' -f2 | cut -d')' -f1)
    file_path="$COMPONENT_PATH/docs/$file"
    echo "<!-- Extracted from docs/$file -->" >> "$TMP_EXPANDED_README_PATH"
    echo >> "$TMP_EXPANDED_README_PATH"
    cat "$file_path" | sed "s/<#ComponentName#>/$COMPONENT_NAME/" >> "$TMP_EXPANDED_README_PATH"
    echo >> "$TMP_EXPANDED_README_PATH" # Ensure that there is always a newline between files.
  else
    echo "$line" >> "$TMP_EXPANDED_README_PATH"
  fi
done

rm "$TMP_README_PATH"

echo "Generating table of contents..."

# Write the table of contents and design/api links
cat "$TMP_EXPANDED_README_PATH" | while read -r line; do
  if [ "$line" = "$DESIGN_AND_API_STRING" ]; then
    echo "## Design & API documentation" >> "$TMP_README_PATH"
    echo "" >> "$TMP_README_PATH"

    if [[ $(grep -e "^guidelines_short_link=" "$VARS_PATH") && $(grep -e "^guidelines_title=" "$VARS_PATH") ]]; then
      guidelines_short_link=$(grep -e "^guidelines_short_link=" "$VARS_PATH" | cut -d'=' -f2-)
      guidelines_title=$(grep -e "^guidelines_title=" "$VARS_PATH" | cut -d'=' -f2-)
      echo "* [Material Design guidelines: $guidelines_title](https://material.io/go/$guidelines_short_link)" >> "$TMP_README_PATH"
    else
      echo ".vars is missing guidelines_short_link= and guidelines_title=."
      echo "No Material Design guidelines link will be generated."
    fi

    if [ -z "$COMPONENT_SITE_PATH" ]; then
      echo "No root_path= value found in .vars, skipping API generation."
      continue
    fi

    pushd "$COMPONENT_PATH" >> /dev/null
    echo "Generating jazzy docs for API links..."

    # Note: Setting `--framework-root=.` makes it so that jazzy can't resolve any symbols outside
    # of the given component. This is intentional; we only want the symbols for this particular
    # component to appear in the generated README. The unfortunate side effect of this is that
    # jazzy generates erroneous "fatal error" statements for imports that live outside of the
    # component.
    echo
    echo "Note: \"fatal error: 'SomeHeader.h' file not found\" errors are ok so long as they are"
    echo "headers that are not within this component directory."
    echo

    jazzy . --output apidocs --framework-root=.
    extract_apis_of_type "Classes" "Class" >> "$TMP_README_PATH"
    extract_apis_of_type "Protocols" "Protocol" >> "$TMP_README_PATH"
    extract_apis_of_type "Enums" "Enumeration" >> "$TMP_README_PATH"
    popd >> /dev/null

  elif [ "$line" = "$TOC_STRING" ]; then
    echo "## Table of contents" >> "$TMP_README_PATH"
    echo "" >> "$TMP_README_PATH"
    grep -e "^#" -e "^$TOC_STRING" "$TMP_EXPANDED_README_PATH" \
      | grep -v "####" \
      | grep -v "#\w" \
      | sed -n '/ toc /,$p' \
      | tail -n +2  > "$TMP_TOC_PATH"

    cat "$TMP_TOC_PATH" | while read toc; do
      indent=$(echo $toc | cut -d' ' -f1 | sed "s/###/  -/" | sed "s/##/-/g")
      text=$(echo $toc | cut -d' ' -f2-)
      url=$(echo $text | awk '{print tolower($0)}')
      url=${url//:} # Strip invalid characters
      url=${url//,} # Strip invalid characters
      url=${url//\/} # Strip invalid characters
      url=${url// /-} # Turn spaces into dashes
      echo "$indent [$text](#$url)" >> "$TMP_README_PATH"
    done
  elif [ "$line" = "$BADGES_STRING" ]; then
    echo "[![Open bugs badge](https://img.shields.io/badge/dynamic/json.svg?label=open%20bugs&url=https%3A%2F%2Fapi.github.com%2Fsearch%2Fissues%3Fq%3Dis%253Aopen%2Blabel%253Atype%253ABug%2Blabel%253A%255B${COMPONENT}%255D&query=%24.total_count)](https://github.com/material-components/material-components-ios/issues?q=is%3Aopen+is%3Aissue+label%3Atype%3ABug+label%3A%5B${COMPONENT}%5D)" >> "$TMP_README_PATH"
  else
    echo "$line" >> "$TMP_README_PATH"
  fi
done

echo "Generating pretty lists..."

# Convert * spec urls to stylized lists
perl -pi -e "s|^\* \[(.+)\]\\((.+?)/go/design-(.+)\\)|  <li class=\"icon-list-item icon-list-item--spec\"><a href=\"\2/go/design-\3\">\1</a></li>|g" "$TMP_README_PATH"

# Convert * list urls to stylized lists
perl -pi -e "s|^\* (.*)\[(.+)\]\\((.+)\\)|  <li class=\"icon-list-item icon-list-item--link\">\1<a href=\"\3\">\2</a></li>|g" "$TMP_README_PATH"

# Convert * list text to stylized lists.
perl -pi -e "s|^\* (.+)$|  <li class=\"icon-list-item icon-list-item\">\1</li>|g" "$TMP_README_PATH"

# Prefix lists with <ul>
perl -p0i -e "s|\n\n  <li|\n\n<ul class=\"icon-list\">\n  <li|g" "$TMP_README_PATH"

# Postfix lists with </ul>
perl -p0i -e "s|li>\n\n|li>\n</ul>\n\n|g" "$TMP_README_PATH"

echo "Rewriting paths..."

# Rewrite relative paths
perl -pi -e "s|\(\.\./|(|g" "$TMP_README_PATH"
perl -pi -e "s|href=\"\.\./|href=\"|g" "$TMP_README_PATH"
perl -pi -e "s|\[(.+)\]\((\w+)\.md\)|[\1](docs/\2.md)|g" "$TMP_README_PATH"

# Rewrite asset paths
perl -pi -e "s|src=\"assets|src=\"docs/assets|g" "$TMP_README_PATH"

mv "$TMP_README_PATH" "$SITE_README_PATH"