#! /bin/bash

# common-helpers.inc
# (c) Copyright 2018 Andreas Müller <schnitzeltony@gmail.com>
# Licensed under terms of GPLv2
#
# This script contains some helper functions and can be sourced by other 
# scripts

# set terminal styles
# are we on terrminal?
if [ -t 1 ] ; then
    # tput available?
    if [ ! "x`which tput 2>/dev/null`" = "x" ] ; then
        # supports colors ?
        ncolors=`tput colors`
        if [ -n "$ncolors" -a  $ncolors -ge 8 ] ; then
            style_bold="`tput bold`"
            style_underline="`tput smul`"
            style_standout="`tput smso`"
            style_normal="`tput sgr0`"
            style_black="`tput setaf 0`"
            style_red="`tput setaf 1`"
            style_green="`tput setaf 2`"
            style_yellow="`tput setaf 3`"
            style_blue="`tput setaf 4`"
            style_magenta="`tput setaf 5`"
            style_cyan="`tput setaf 6`"
            style_white="`tput setaf 7`"
        fi
    fi
fi

# base tempdir
base_tempdir=`mktemp -u`
base_tempdir=`dirname "$base_tempdir"`

# ErrorOut outputs error text in first param and exits script
ErrorOut() {
    echo -e "\n${style_red}${style_bold}${1}${style_normal}\n" >&2
    exit -1
}

# EvalEx executes a command, checks if it succeeds and ouputs messages
# It expectes the following parameters:
# 1. Command
# 2. Message on start (optional)
# 3. Message on successful end (optional)
# 4. Message on error end (optional)
EvalEx() {
    if [ -z "${1}" ] ; then
        ErrorOut "EvalEx: No command found in first parameter"
    fi
    if [ -n "${2}" ] ; then
        echo -e "${style_magenta}${2}${style_normal}"
    fi
    if eval ${1} ; then
        if [ -n "${3}" ] ; then
            echo -e "${style_green}${3}${style_normal}"
        fi
    else
        if [ -n "${4}" ] ; then
            ErrorText="${4}"
        else
            ErrorText="An error occured!"
        fi
        ErrorOut "${ErrorText}\nCommand was: '${1}'"
    fi
}

# EvalExAuto is similar it EvalEx and expectes the following parameters:
# 1. Command
# 2. Message on start
# The end messages are created by extracting first word of start message
# and appening 'done' respectively 'failed'
EvalExAuto() {
    # Remove linefeeds / catch 'Start...' case / extract forst
    StartAligned=`echo -e $2 | tr '\n' ' ' | sed 's:\.: :' | awk '{ print $1 }' `
    EndMessageOk="`echo $StartAligned` done."
    EndMessageFail="`echo $StartAligned` failed!"
    EvalEx "$1" "$2" "$EndMessageOk" "$EndMessageFail"
}

# CheckPrerequisite checks if required hosttool is found on host. In case not
# it outputs a message and exits script.
CheckPrerequisite() {
    if [ "x`which $1 2>/dev/null`" = "x" ] ; then
        ErrorOut "You need to install $1 first!"
    fi
}

# GetBitbakeEnvVar starts bitbake -e and extracts environment variable.
# Bitbake Variable is stored in BitbakeEnvVar
GetBitbakeEnvVar() {
    if [ "x`which bitbake 2>/dev/null`" = "x" ] ; then
        ErrorOut "Bitbake not found! Script can only run in build environment."
    fi
    EvalExAuto "BitbakeEnvVar=`bitbake -e | grep ^${1}=`" "Run bitbake -e"
    if [ -n "${BitbakeEnvVar}" ]; then
        BitbakeEnvVar=`echo ${BitbakeEnvVar=} | sed -e s:${1}=::`
    fi
}