#!/bin/bash
# gen-catalog - Generate SFCC (Demandware) catalog XML for testing
#
# Usage:
#   gen-catalog <base_count> <variants_per_base> [catalog_id]
#   gen-catalog -h
#
# Options:
#   base_count          Number of base products to generate (positive integer)
#   variants_per_base   Number of variants per base product (positive integer)
#   catalog_id          Catalog ID (default: test-catalog)
#   -h, --help          Show help message

_gen_catalog() (
    local SCRIPT_NAME; SCRIPT_NAME="$(basename "${BASH_SOURCE[0]}")"
    case "${BASH_SOURCE[0]}" in /dev/*|/proc/*) SCRIPT_NAME="" ;; esac
    case "$SCRIPT_NAME" in ""|bash|sh|zsh|dash) SCRIPT_NAME="gen-catalog" ;; esac

    _show_help() {
        local s; [ -t 1 ] && s=$'\033[4m'
        local r; [ -t 1 ] && r=$'\033[24m'
        echo "NAME"
        echo "  $SCRIPT_NAME - generate SFCC catalog XML"
        echo "SYNOPSIS"
        echo "  $SCRIPT_NAME ${s}base_count${r} ${s}variants_per_base${r} [${s}catalog_id${r}]"
        echo "  $SCRIPT_NAME -h"
        echo "DESCRIPTION"
        echo "  Generates a Demandware/SFCC catalog XML document with the specified number"
        echo "  of base products, each with the given number of variants. Output is written"
        echo "  to stdout."
        echo "OPTIONS"
        echo "  ${s}base_count${r}          Number of base products to generate"
        echo "  ${s}variants_per_base${r}   Number of variants per base product"
        echo "  ${s}catalog_id${r}          Catalog ID (default: test-catalog)"
        echo "  -h, --help          Show this help message"
        echo "EXIT STATUS"
        echo "  0  Success"
        echo "  2  Usage error (missing or non-positive-integer arg)"
    }

    _error() { echo "[ERR][$SCRIPT_NAME] $*" >&2; }

    main() {
        local base_count="$1"
        local variants_per_base="$2"
        local catalog_id="$3"

        if [ ! "$base_count" ] || [ ! "$variants_per_base" ]; then
            _error "Must provide BASE_COUNT and VARIANTS_PER_BASE. Run \`$SCRIPT_NAME -h\` for usage"
            return 2
        fi

        case "$base_count" in
            *[!0-9]*)
                _error "BASE_COUNT must be a positive integer"
                return 2
                ;;
        esac

        case "$variants_per_base" in
            *[!0-9]*)
                _error "VARIANTS_PER_BASE must be a positive integer"
                return 2
                ;;
        esac

        if [ "$base_count" -le 0 ] || [ "$variants_per_base" -le 0 ]; then
            _error "BASE_COUNT and VARIANTS_PER_BASE must be greater than zero"
            return 2
        fi

        if [ ! "$catalog_id" ]; then
            catalog_id="test-catalog"
        fi

        print_header "$catalog_id"
        print_all_in_order "$base_count" "$variants_per_base"
        print_footer
    }

    print_header() {
        local catalog_id="$1"

        echo '<?xml version="1.0" encoding="UTF-8"?>'
        echo '<catalog xmlns="http://www.demandware.com/xml/impex/catalog/2006-10-31"'
        echo '         xmlns:xml="http://www.w3.org/XML/1998/namespace"'
        echo "         catalog-id=\"$catalog_id\">"
        echo '    <header/>'
    }

    print_footer() {
        echo '</catalog>'
    }

    print_all_in_order() {
        local base_count="$1"
        local variants_per_base="$2"

        _print_base() {
            local base_id="$1"
            local variants_per_base="$2"

            echo "    <product product-id=\"$base_id\">"
            echo "        <display-name xml:lang=\"en\">$base_id</display-name>"
            echo '        <variations>'
            echo '            <variants>'

            local i=1
            while [ "$i" -le "$variants_per_base" ]; do
                local num
                num="$(printf '%03d' "$i")"
                local vid="$base_id-VAR-$num"

                if [ "$i" -eq 1 ]; then
                    echo "                <variant product-id=\"$vid\" default=\"true\"/>"
                else
                    echo "                <variant product-id=\"$vid\"/>"
                fi

                i=$((i + 1))
            done

            echo '            </variants>'
            echo '        </variations>'
            echo '    </product>'
        }

        _print_variants() {
            local base_id="$1"
            local variants_per_base="$2"

            local i=1
            while [ "$i" -le "$variants_per_base" ]; do
                local num
                num="$(printf '%03d' "$i")"
                local vid="$base_id-VAR-$num"

                echo "    <product product-id=\"$vid\">"
                echo "        <display-name xml:lang=\"en\">$base_id Variant $num</display-name>"
                echo '    </product>'

                i=$((i + 1))
            done
        }

        # Ordered output:
        # BASE1
        # BASE1 variants
        # BASE2
        # BASE2 variants
        local b=1
        while [ "$b" -le "$base_count" ]; do
            local base_id="BASE$b"

            _print_base "$base_id" "$variants_per_base"
            _print_variants "$base_id" "$variants_per_base"

            b=$((b + 1))
        done
    }

    case "$1" in
        -h|--help) _show_help; return 0 ;;
    esac

    main "$@"
)

_gen_catalog "$@"
__gen_catalog_rc=$?
unset -f _gen_catalog
if [ -n "${BASH_SOURCE[0]}" ] && [ "${BASH_SOURCE[0]}" != "$0" ]; then
    eval "unset __gen_catalog_rc; return $__gen_catalog_rc"
fi
eval "unset __gen_catalog_rc; exit $__gen_catalog_rc"