import * as prettier from 'prettier';
import { log } from '../utils/log';

const formatOptions: prettier.Options = {
    semi: true,
    singleQuote: true,
    trailingComma: 'es5',
    tabWidth: 4,
    printWidth: 85,
    endOfLine: 'lf',
    arrowParens: 'always',
    parser: 'typescript',
};

export function formatFunctionSignature(text: string): string {
    const varLike = `let ${text}`;
    return formatVariableSignature(varLike).replace(/^let\s/, '');
}

export function formatVariableSignature(text: string): string {
    // Temporarily replace the invalid variable name `default`
    const escapedText = text.replace('default:', '_______:');
    return formatText(escapedText).replace('_______:', 'default:');
}

export function formatClassMember(text: string): string {
    const wrapped = `class C { ${text} }`;
    return formatWrappedMember(wrapped);
}

export function formatInterfaceMember(text: string): string {
    const wrapped = `interface I { ${text} }`;
    return formatWrappedMember(wrapped);
}

export function formatEnumMember(text: string): string {
    const wrapped = `enum E { ${text} }`;
    return formatWrappedMember(wrapped).replace(/,$/, '');
}

function formatWrappedMember(text: string): string {
    const formatted = formatText(text);
    const lines = formatted.split('\n');

    // Remove wrapper and member indentation
    const member = lines
        .slice(1, lines.length - 1)
        .map((line) => line.replace(/^\s{4}/, ''))
        .join('\n');

    return member;
}

export function formatText(text: string): string {
    let formatted = text
        .trim()
        .replace(/^export\s+/, '')
        .replace(/^default\s+/, '')
        .replace(/^declare\s+/, '');

    try {
        formatted = prettier.format(formatted, formatOptions);
    } catch (err) {
        // istanbul ignore next
        log('formatText: formatting error: %O', { err });
    }

    return formatted.trim();
}