const TYPE_KEY = "__scutil__type__";

// Quick hacky parser, which translates output into valid JSON:
export function parseScutilOutput(output: string): {} {
    try {
        // Unclear how this happens, but it seems that it can in some cases:
        if (output === '') return {};

        const unquotedJsonString = output
            // Reduce type markers to just an inline __scutil__type__ marker on array objects:
            .replace(/<dictionary> /g, '')
            .replace(/<array> {/g, `{\n${TYPE_KEY} : array`)
            .trim();

        // Turn unquoted key/value string into a string of quote key values (but with no commas).
        // We effectively parse by splitting on the first " : " in each line, if present.
        const jsonKeyValues = unquotedJsonString
            .split('\n')
            .map((line) => {
                const [key, value] = line.split(/ : (.*)/);

                if (value === undefined) return key.trim();
                else if (value === '{') return `"${key.trim()}": {`;
                else return `"${key.trim()}": ${JSON.stringify(value.trim())}`;
            });

        // Insert commas everywhere they're needed
        const jsonFormattedString = jsonKeyValues
            .reduce((jsonString, nextValue) => {
                if (!jsonString || jsonString.endsWith("{") || nextValue === "}") {
                    // JSON has no commas after/before object {} tokens or
                    // at the very start of the string:
                    return jsonString + nextValue;
                } else {
                    return jsonString + ', ' + nextValue;
                }
            }, "");

        const data = JSON.parse(jsonFormattedString, (key, value) => {
            // Convert array-tagged objects back into arrays:
            if (value[TYPE_KEY] === 'array') {
                delete value[TYPE_KEY];
                return Object.values(value);
            } else {
                return value;
            }
        });

        return data;
    } catch (e) {
        throw Object.assign(
            new Error("Unexpected scutil proxy output format"),
            { scutilOutput: output } // Attach output for debugging elsewhere
        );
    }
}