#!/bin/bash

# Originally written by Anon, modified by Emil to better match Bake functionality

# Issues: sloooow, fails to handle multi-line statements

VERSION="20240302"

BLUE='\033[34m'
GREEN='\033[32m'
YELLOW='\033[93m'
DIM='\033[2m'
BOLD='\033[1m'
NORMAL='\033[0m'

MARKNAME="@BAKE"
MARK="${MARKNAME} "
MARKSTR="${GREEN}${MARKNAME}${NORMAL}"

enable -n echo

usage() {
    echo -e "$0: [option] ${BOLD}target-file${NORMAL} [${GREEN}arguments${NORMAL} ...]\n"
    echo -e "Use the format \`${BOLD}@BAKE${NORMAL} cmd ...' within the ${BOLD}target-file${NORMAL}."
    echo -e "This will execute until the end of line, or if existing, until the ${BOLD}@STOP${NORMAL} marker.\n"
    echo -e "Options [Must be first]"
    echo -e "\t${DIM}-h --help${NORMAL}, ${BOLD}-n --dry-run${NORMAL}\n"
    echo -e "Expansions\n"
    echo -e "\t${YELLOW}@FILENAME${NORMAL}  returns target-file                (abc.x.txt)"
    echo -e "\t${YELLOW}@SHORT${NORMAL}     returns target-file without suffix (^-> abc.x)"
    echo -e "\t${YELLOW}@ARGS${NORMAL}      returns ${GREEN}arguments${NORMAL}"
    echo -e "\t${YELLOW}@{${NORMAL}${BOLD}EXPUNGE_THIS_FILE${YELLOW}}${NORMAL} inline region to delete this or many files or directories,"
    echo -e "\tnon-recursive, only one file per block, removed from left to right. This has no\n\tinfluence on the normal command execution.\n"
}

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

if [[ $1 == "-h" ]] || [[ $1 == "--help" ]]; then
    usage
    exit 0
fi

if [[ $1 == "-v" ]] || [[ $1 == "--version" ]]; then
    echo -e "$0: $VERSION"
    exit 0
fi

run=1
if [[ $1 == "-n" ]] || [[ $1 == "--dry-run" ]]; then
    if [[ $# -lt 2 ]]; then
        usage
        exit 1
    fi
    run=0
    shift 1
fi

input_file=$1
shift 1

if [[ ! -f $input_file ]]; then
    echo -e "Input file '$input_file' does not exist." >&2
    exit 1
fi

cd $(dirname "$(readlink -f "$input_file")")
input_file=${input_file##*/}

line=$(grep "$MARK" "$input_file" | head -1)

if [[ -n $line ]]; then

    line=${line//\$@/$input_file}
    line=${line//\$\*/${input_file%.*}}
    line=${line//\$+/$@}
    line=${line//@FILENAME/$input_file}
    line=${line//@SHORT/${input_file%.*}}
    line=${line//@ARGS/$@}
    line=$(echo "$line" | sed 's/@STOP.*//')

    echo -e "${BOLD}${GREEN}$0${NORMAL}: ${line#*${MARK}}"

    line=$(echo "$line" | sed -E 's/@\{([^ \}]+?)\}/\1/')
    command="${line#*${MARK}}"
    if [[ $run -eq 1 ]]; then
        echo -e "${BOLD}${GREEN}output${NORMAL}:"
        sh -c "$command"
    fi
else
    echo -e "${MARKSTR} is not defined." >&2
    exit 1
fi