#!/bin/env bash

function checkout_commit() {
    # args:
    # PIPE_ROOT: The root path of the pipeline
    # STEP_NAME: The name of the step to setup
    # COMMIT: The commit to be used
    local PIPE_ROOT=$1
    local STEP_NAME=$2
    local COMMIT=$4

    local STEPS_DIR=${PIPE_ROOT}/pipeline
    local STEP_DIR=${STEPS_DIR}/${STEP_NAME}
    
    cd ${STEP_DIR}
    git checkout ${COMMIT} > /dev/null 2>&1

    if [[ $? != 0 ]];
    then
	echo "ERROR: could not checkout the provided commit"
	return $?
    fi;

    local CUR_COMMIT=`git rev-parse --short HEAD`
    echo "The repo is now in commit: ${CUR_COMMIT}"

    cd ${PIPE_ROOT}

    return 0

}
    
function setup_step_from_git_repo() {
    # args:
    # PIPE_ROOT: The root path of the pipeline
    # STEP_NAME: The name of the step to setup
    # REPO_URL: The https url of the repo (must be public)
    # COMMIT: The commit to be used
    local PIPE_ROOT=$1
    local STEP_NAME=$2
    local REPO_URL=$3
    local COMMIT=$4
    
    local STEPS_DIR="${PIPE_ROOT}/pipeline"
    local STEP_DIR="${STEPS_DIR}/${STEP_NAME}"

    echo ">>> Setup ${STEP_NAME} from ${REPO_URL}:${COMMIT}"

    # If the step does not exists in the pipeline
    if [ ! -d ${STEP_DIR} ];
    then
	cd ${STEPS_DIR}
	git clone ${REPO_URL}

	if [[ $? != 0 ]];
	then
	    echo "ERROR: could not git clone from the provided url"
	    return $?
	fi;
	
	cd ${PIPE_ROOT}

    fi;

    # if git repo then Checkout commit
    if [ -d ${STEP_DIR}/.git ];
    then
	checkout_commit ${PIPE_ROOT} ${STEP_NAME} ${COMMIT}

	if [[ $? != 0 ]];
	then
	    return $?
	fi;
	
    else
	echo "ERROR: the source must be under Git version control"
	return 1
	
    fi;

    return 0

}


function setup_step() {
    # args:
    # PIPE_ROOT: The root path of the pipeline
    # STEP_NAME: The name of the step to setup
    local PIPE_ROOT=$1
    local STEP_NAME=$2

    local STEPS=`./stoml ${PIPE_ROOT}/config.toml steps`
    
    if [[ ! " ${STEPS[*]} " =~ " ${STEP_NAME} " ]]; then
	echo "ERROR: the step: ${STEP_NAME} is not defined."
	return 1
    fi
    
    local TYPE=`./stoml ${PIPE_ROOT}/config.toml steps.${STEP_NAME}.type`

    case $TYPE in

	git_repo)
	    local REPO_URL=`./stoml ${PIPE_ROOT}/config.toml steps.${STEP_NAME}.repo_url`
	    local COMMIT=`./stoml ${PIPE_ROOT}/config.toml steps.${STEP_NAME}.commit`

	    # setup the step
	    setup_step_from_git_repo ${PIPE_ROOT} ${STEP_NAME} ${REPO_URL} ${COMMIT}

	    if [[ $? != 0 ]];
	    then
		return $?
	    fi;

	    # create a runtime-parameters for the step
	    if [ ! -d ${PIPE_ROOT}/${RUNTIME_PARAMS}/${STEP_NAME} ];
	    then
		mkdir ${PIPE_ROOT}/${RUNTIME_PARAMS}/${STEP_NAME}

		if [[ $? != 0 ]];
		then
		    echo "ERROR: Could not create the runtime-parameters folder. Do you have the write-rights there: ${PIPE_ROOT}/${RUNTIME_PARAM} ?"
		    return $?
		fi;
		
	    fi;
	    
	    ;;

	*)
	    echo "ERROR: TYPE: ${TYPE} not supported."
	    return 1 
	    ;;
    esac

    return 0
    
}

function setup_pipeline() {

    local PIPE_ROOT=`pwd`
    local STEP_NAMES=(`./stoml ${PIPE_ROOT}/config.toml pipeline`)

    echo ">>> Steps: ${STEP_NAMES[@]}"

    for STEP_NAME in "${STEP_NAMES[@]}";
    do

	setup_step ${PIPE_ROOT} ${STEP_NAME}

	if [[ $? != 0 ]];
	then
	    echo "ERROR: Could not setup step: ${STEP_NAME}"
	    return $?
	fi;

    done;

    return 0
}