#!/bin/bash
# ------------------------------------------------------------------------------
# Variables substitution function
# This file is part of the init.sh project
# Copyright (c) 2019-2024 Geoffray Levasseur <fatalerrors@geoffray-levasseur.org>
# ------------------------------------------------------------------------------
# This file is distributed under 3-clause BSD license.
# The complete license agreement can be obtained at:
# https://opensource.org/licenses/BSD-3-Clause
# ------------------------------------------------------------------------------


# ------------------------------------------------------------------------------
# Replace @VAR@ in a text file by the corresponding $VAR value
# The --delimiter or -d option allow to use something else than @
setvar() {
    local delimiter="@"
    local vars=()
    local file

    # Parse arguments
    while [[ $# -gt 0 ]]; do
        case "$1" in
            --delimiter|-d)
                shift
                delimiter="${1:-@}"
                ;;
            -*)
                prnt E "setvar(): Unknown option: $1"
                die 
                ;;
            *)
                if [[ -f $1 && $# -eq 1 ]]; then
                    file="$1"
                else
                    vars+=("$1")
                fi
                ;;
        esac
        shift
    done

    if [[ -z $file ]]; then
        prnt E "Usage: setvar [--delimiter D] VAR1 [VAR2 ...] <file>"
        die 1
    fi
    if [[ ${#vars[@]} -eq 0 ]]; then
        prnt E "No variable name(s) provided."
        die 1
    fi

    local var val escaped pattern
    for var in "${vars[@]}"; do
        val="${!var}"
        if [[ -z $val ]]; then
            prnt W "Variable '$var' is unset or empty; skipped."
            continue
        fi

        # Échapper les caractères spéciaux pour sed
        escaped=$(printf '%s' "$val" | sed -e 's/[\/&]/\\&/g')

        pattern="${delimiter}${var}${delimiter}"

        prnt I "Replacing $pattern with $val in $file"
        sed -i -e "s|$pattern|$escaped|g" "$file"
    done
}
export -f setvar
# ------------------------------------------------------------------------------


# ------------------------------------------------------------------------------
# Replace @VAR@ in a text file by the corresponding values available in the
# environment. The --delimiter or -d option allow to use something else than @
setvars_from_env() {
    local file delimiter="@"
    while [[ $# -gt 0 ]]; do
        case "$1" in
            -d|--delimiter)
                shift
                delimiter="${1:-@}"
                ;;
            *)
                file="$1"
                ;;
        esac
        shift
    done

    [[ -f $file ]] || {
        prnt E "File not found: $file"
        die 1
    }

    local vars
    vars=$(grep -o "${delimiter}[A-Z0-9_]\+${delimiter}" "$file" | sort -u | tr -d "$delimiter")
    [[ -z $vars ]] && return 0

    setvar --delimiter "$delimiter" $vars "$file"
}
export -f setvars_from_env
# ------------------------------------------------------------------------------


# EOF