#!/usr/bin/env bash
# ------------------------------------------------------------------------------
# Copyright (c) 2013-2026 Geoffray Levasseur <fatalerrors@geoffray-levasseur.org>
# Protected by the BSD3 license. Please read bellow for details.
#
# * Redistribution and use in source and binary forms,
# * with or without modification, are permitted provided
# * that the following conditions are met:
# *
# *   Redistributions of source code must retain the above
# *   copyright notice, this list of conditions and the
# *   following disclaimer.
# *
# *   Redistributions in binary form must reproduce the above
# *   copyright notice, this list of conditions and the following
# *   disclaimer in the documentation and/or other materials
# *   provided with the distribution.
# *
# *   Neither the name of the copyright holder nor the names
# *   of any other contributors may be used to endorse or
# *   promote products derived from this software without
# *   specific prior written permission.
# *
# * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
# * CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
# * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
# * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
# * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
# * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
# * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
# * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
# * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
# * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
# * OF SUCH DAMAGE.
# ------------------------------------------------------------------------------

# ------------------------------------------------------------------------------
# Save or update a key=value pair in a section of the profile configuration file.
# The user configuration ($HOME/.profile.conf) is updated when it exists,
# otherwise the installation configuration ($PROFILE_CONF or $MYPATH/profile.conf)
# is used.  The section header is created automatically when absent.
#
# Usage: conf_save <section> <key> <value>
#   section : INI section name without brackets, e.g. "prompt" for [prompt]
#   key     : variable name to set (alphanumeric and underscore only)
#   value   : value to assign (may be empty)
conf_save()
{
    if [[ $# -ne 3 ]]; then
        disp E "Usage: conf_save <section> <key> <value>"
        return 1
    fi

    local section="$1" key="$2" value="$3"

    if ! [[ "$section" =~ ^[a-zA-Z_][a-zA-Z0-9_]*$ ]]; then
        disp E "conf_save: invalid section name '${section}' (alphanumeric and underscore only)."
        return 1
    fi
    if ! [[ "$key" =~ ^[a-zA-Z_][a-zA-Z0-9_]*$ ]]; then
        disp E "conf_save: invalid key name '${key}' (alphanumeric and underscore only)."
        return 1
    fi

    local conf_file
    if [[ -f "$HOME/.profile.conf" ]]; then
        conf_file="$HOME/.profile.conf"
    else
        conf_file="${PROFILE_CONF:-${MYPATH}/profile.conf}"
    fi

    local conf_dir="${conf_file%/*}"
    [[ -d "$conf_dir" ]] || mkdir -p "$conf_dir" || {
        disp E "conf_save: unable to create configuration directory: ${conf_dir}"
        return 1
    }

    if [[ ! -e "$conf_file" ]]; then
        {
            printf "[%s]\n" "$section"
            printf "%s=%s\n" "$key" "$value"
        } > "$conf_file" || {
            disp E "conf_save: unable to write configuration file: ${conf_file}"
            return 1
        }
        return 0
    fi

    local tmp_file="${conf_file}.tmp.$$"
    awk -v sec="$section" -v key="$key" -v val="$value" '
        BEGIN {
            in_sec  = 0
            saw_sec = 0
            wrote   = 0
        }

        {
            if ($0 ~ /^\[[^]]+\][[:space:]]*$/) {
                if (in_sec && !wrote) {
                    print key "=" val
                    wrote = 1
                }

                if ($0 ~ ("^\\[" sec "\\][[:space:]]*$")) {
                    in_sec  = 1
                    saw_sec = 1
                } else {
                    in_sec = 0
                }

                print
                next
            }

            if (in_sec && $0 ~ ("^[[:space:]]*" key "[[:space:]]*=")) {
                if (!wrote) {
                    print key "=" val
                    wrote = 1
                }
                next
            }

            print
        }

        END {
            if (in_sec && !wrote) {
                print key "=" val
            }
            if (!saw_sec) {
                print ""
                print "[" sec "]"
                print key "=" val
            }
        }
    ' "$conf_file" > "$tmp_file" || {
        rm -f "$tmp_file"
        disp E "conf_save: unable to update configuration file: ${conf_file}"
        return 1
    }

    mv "$tmp_file" "$conf_file" || {
        rm -f "$tmp_file"
        disp E "conf_save: unable to replace configuration file: ${conf_file}"
        return 1
    }
}
export -f conf_save
# ------------------------------------------------------------------------------


# EOF