#!/bin/bash


warn() {
    echo "$@" >&2
}

die() {
    echo "$@" >&2
    exit 3
}

content_desc() {
    local c=$1
    case $c in
        \ ) echo space ;;
        \!) echo exclamation mark ;;
        \$) echo dollar sign ;;
        \&) echo ampersand ;;
        \() echo opening bracket ;;
        \)) echo closing bracket ;;
        \*) echo asterisk ;;
        \;) echo semicolon ;;
        \?) echo question mark ;;
        \\) echo backslash ;;
        \`) echo tick mark;;
        \>) echo greater than ;;
        \<) echo less than ;;
        \{) echo opening curly brace ;;
        \|) echo pipe symbol ;;
        \}) echo closing curly brace ;;
        BS) echo backslash ;;
        SQ) echo single quote ;;
        DQ) echo double quote ;;
        TAB) echo tab ;;
        ES) echo empty string ;;
        NL) echo newline ;;
        A) echo letter A ;;
    esac
}

mode_name() {
    local mode=$1
    case $mode in
        bs) echo backslash escaping ;;
        sq) echo single quoting ;;
        dq) echo double quoting ;;
    esac
}


mktest() {
    local mode=$1; shift
    local mode_name
    local content_desc
    mode_name="$(mode_name "$mode")"
    local c
    local self=$0
    printf 'test "parse: %s (generated)" {\n' "$mode_name"
    printf '    // TEST GENERATED BY %s\n' "$self"
    #shellcheck disable=SC2016
    for c in "$@"; do
        content_desc="$(content_desc "$c")"
        # every backslash needs to be doubled because of printf.
        # some backslashes need to be doubled again becase of syntax (eg. `"\\\\" is 2 backslashes in Zig)
        case $mode:$c in
            bs:BS)      printf '    try parse_t("\\\\\\\\", Result{ .tokens = &.{"\\\\"} });  // %s `\\` (%s)\n' "$mode_name" "$content_desc" ;;
            bs:DQ)      printf '    try parse_t("\\\\\\"", Result{ .tokens = &.{"\\""} });  // %s `"` (%s)\n' "$mode_name" "$content_desc" ;;
            bs:ES)      true ;;     # impossible case
            bs:NL)      printf '    try parse_t("\\\\\\n", Result{ .tokens = &.{"\\n"} });  // %s `\\n` (%s)\n' "$mode_name" "$content_desc" ;;
            bs:SQ)      printf '    try parse_t("\\\\%s", Result{ .tokens = &.{"%s"} });  // %s `%s` (%s)\n' "'" "'" "$mode_name" "'" "$content_desc" ;;
            bs:TAB)     printf '    try parse_t("\\\\\\t", Result{ .tokens = &.{"\\t"} });  // %s `\\t` (%s)\n' "$mode_name" "$content_desc"  ;;
            bs:*)       printf '    try parse_t("\\\\%s", Result{ .tokens = &.{"%s"} });  // %s `%s` (%s)\n' "$c" "$c" "$mode_name" "$c" "$content_desc" ;;
            sq:NL)      printf '    try parse_t("%s\\n%s", Result{ .tokens = &.{"\\n"} });  // %s `\\n` (%s)\n' "'" "'" "$mode_name" "$content_desc" ;;
            sq:TAB)     printf '    try parse_t("%s\\t%s", Result{ .tokens = &.{"\\t"} });  // %s `\\t` (%s)\n' "'" "'" "$mode_name" "$content_desc" ;;
            sq:DQ)      printf '    try parse_t("%s\\"%s", Result{ .tokens = &.{"\\""} });  // %s `"` (%s)\n' "'" "'" "$mode_name" "$content_desc" ;;
            sq:ES)      printf '    try parse_t("%s%s", Result{ .tokens = &.{""} });  // %s `\\` (%s)\n' "'" "'" "$mode_name" "$content_desc" ;;
            sq:BS)      printf '    try parse_t("%s\\\\%s", Result{ .tokens = &.{"\\\\"} });  // %s `\\` (%s)\n' "'" "'" "$mode_name" "$content_desc" ;;
            sq:SQ)      true ;;     # impossible case
            sq:*)       printf '    try parse_t("'"'"'%s'"'"'", Result{ .tokens = &.{"%s"} });  // %s `%s` (%s)\n' "$c" "$c" "$mode_name" "$c" "$content_desc" ;;
            dq:BS)      printf '    try parse_t("\\"\\\\\\\\\\"", Result{ .tokens = &.{"\\\\"} });  // %s `\\` (%s)\n' "$mode_name" "$content_desc" ;;
            dq:DQ)      printf '    try parse_t("\\"\\\\\\"\\"", Result{ .tokens = &.{"\\""} });  // %s `"` (%s)\n' "$mode_name" "$content_desc" ;;
            dq:ES)      printf '    try parse_t("\\"\\"", Result{ .tokens = &.{""} });  // %s `\\` (%s)\n' "$mode_name" "$content_desc" ;;
            dq:NL)      printf '    try parse_t("\\"\\n\\"", Result{ .tokens = &.{"\\n"} });  // %s `\\n` (%s)\n' "$mode_name" "$content_desc" ;;
            dq:SQ)      printf '    try parse_t("\\"%s\\"", Result{ .tokens = &.{"%s"} });  // %s `%s` (%s)\n' "'" "'" "$mode_name" "'" "$content_desc" ;;
            dq:TAB)     printf '    try parse_t("\\"\\t\\"", Result{ .tokens = &.{"\\t"} });  // %s `\\t` (tab)\n' "$mode_name" ;;
            dq:*)       printf '    try parse_t("\\"%s\\"", Result{ .tokens = &.{"%s"} });  // %s `%s` (%s)\n' "$c" "$c" "$mode_name" "$c" "$content_desc" ;;
            *)  die "unknown character or mode: c=$c mode=$mode" ;;
        esac
    done
    printf '}\n'
    echo
}

main() {
    local cases=(
        '!'
        '$'
        '&'
        '('
        ')'
        '*'
        ';'
        '?'
        '`'
        '{'
        '>'
        '<'
        '|'
        '}'
        ' '
        SQ
        DQ
        BS
        TAB
        NL
        ES
        A
    )
    mktest bs "${cases[@]}"
    mktest sq "${cases[@]}"
    mktest dq "${cases[@]}"
}

main "$@"