#!/bin/bash

# Git-flow release automation with
# version bumping and changelog generation
#
# Based on many great starting points:
#   https://gist.github.com/mareksuscak/1f206fbc3bb9d97dec9c
#   https://gist.github.com/pete-otaqui/4188238
#   https://gist.github.com/bclinkinbeard/1331790

# file in which to update version number
FILE_VERSION="VERSION"
FILE_CHANGELOG="CHANGELOG.md"

NOW="$(date +'%Y-%m-%d')"
RED="\033[1;31m"
GREEN="\033[0;32m"
YELLOW="\033[1;33m"
BLUE="\033[1;34m"
PURPLE="\033[1;35m"
CYAN="\033[1;36m"
WHITE="\033[1;37m"
RESET="\033[0m"

LATEST_HASH=`git log --pretty=format:'%h' -n 1`

# current Git branch
BRANCH_CURRENT=$(git symbolic-ref HEAD | sed -e 's,.*/\(.*\),\1,')

# establish branch and tag name variables
BRANCH_DEV=develop
BRANCH_MASTER=master


QUESTION_FLAG="${GREEN}?"
WARNING_FLAG="${YELLOW}!"
ERROR_FLAG="${RED}!"
NOTICE_FLAG="${CYAN}❯"

ADJUSTMENTS_MSG="${QUESTION_FLAG} ${CYAN}Now you can make adjustments to ${WHITE}CHANGELOG.md${CYAN}. Then press enter to continue."
PUSHING_MSG="${NOTICE_FLAG} Pushing new version to the ${WHITE}origin${CYAN}..."


#if [ ! $LATEST_HASH ]; then
#    echo -e "${ERROR_FLAG} No commits in the repo. Cannot continue."
#    exit 1
#fi

# Do we have a file with our version?
if [ ! -f $FILE_VERSION ]; then
    echo -ne "${QUESTION_FLAG} ${CYAN}Can't find version file (${FILE_VERSION}), create one?"

    read RESPONSE
    if [[ $RESPONSE =~ [yY](es)* ]] || [ "$RESPONSE" = "" ]; then
        echo "0.0.0" > $FILE_VERSION
    else
        exit 1
    fi
fi

# Do we have a file with our changes?
if [ ! -f $FILE_CHANGELOG ]; then
    echo -ne "${QUESTION_FLAG} ${CYAN}Can't find changelog file (${FILE_CHANGELOG}), create one?"

    read RESPONSE
    if [[ $RESPONSE =~ [yY](es)* ]] || [ "$RESPONSE" = "" ]; then
        echo "" > $FILE_CHANGELOG
    else
        exit 1
    fi
fi

# Continue to guess new value for our version
BASE_STRING=`cat $FILE_VERSION`

if [ $BASE_STRING = "" ]; then
    BASE_STRING="0.0.0"
fi

BASE_LIST=(`echo $BASE_STRING | tr '.' ' '`)
V_MAJOR=${BASE_LIST[0]}
V_MINOR=${BASE_LIST[1]}
V_PATCH=${BASE_LIST[2]}

echo -e "${NOTICE_FLAG} Current version: ${WHITE}$BASE_STRING"
echo -e "${NOTICE_FLAG} Latest commit hash: ${WHITE}$LATEST_HASH"

# We default to patch level bump
V_PATCH=$((V_PATCH + 1))


SUGGESTED_VERSION="$V_MAJOR.$V_MINOR.$V_PATCH"
echo -ne "${QUESTION_FLAG} ${CYAN}Enter a version number [${WHITE}$SUGGESTED_VERSION${CYAN}]: "
read NEW_VERSION
if [ "$NEW_VERSION" = "" ]; then
    NEW_VERSION=$SUGGESTED_VERSION
fi
echo -e "${NOTICE_FLAG} Will set new version to be ${WHITE}$NEW_VERSION"
echo ""
echo -ne "${WARNING_FLAG} This is the last chance to bail out before anything has happened."
read

# Set up our release branch name
BRANCH_RELEASE=release-$NEW_VERSION

# create the release branch from the -develop branch
git checkout -b $BRANCH_RELEASE $BRANCH_DEV

# Set our new version to our version file
echo $NEW_VERSION > $FILE_VERSION

# Create our changelog
echo "## $NEW_VERSION ($NOW)" > tmpfile
git log --pretty=format:"  - %H %ad | %s%d [%an]" --date=short "$BASE_STRING"...HEAD >> tmpfile
echo "" >> tmpfile
echo "" >> tmpfile
cat $FILE_CHANGELOG >> tmpfile
mv tmpfile $FILE_CHANGELOG

echo -e "$ADJUSTMENTS_MSG"
read
echo -e "$PUSHING_MSG"

# Make sure changes have been added
git add $FILE_VERSION $FILE_CHANGELOG

# Commit version number increment
git commit -am "Incrementing version number to $NEW_VERSION"

# Merge release branch with the new version number into master
git checkout $BRANCH_MASTER
git merge --no-ff $BRANCH_RELEASE

# Create tag for new version from -master
git tag -am "Tag version ${NEW_VERSION}." "$NEW_VERSION"

# Merge release branch with the new version number back into develop
git checkout $BRANCH_DEV
git merge --no-ff $BRANCH_RELEASE

# Remove release branch
git branch -d $BRANCH_RELEASE