import { ICodeBuilder } from './ICodeBuilder';

const NewLine = '\n';
const TotalFunctionSeparatorChars = 58;

export abstract class CodeBuilder implements ICodeBuilder {
    private readonly lines = new Array<string>();

    // Returns current line starting from 0 (no lines), or 1 (have single line)
    public get currentLine(): number {
        return this.lines.length;
    }

    public appendLine(code?: string): CodeBuilder {
        if (!code) {
            this.lines.push('');
            return this;
        }
        const lines = code.match(/[^\r\n]+/g);
        for (const line of lines) {
            this.lines.push(line);
        }
        return this;
    }

    public appendTrailingHyphensCommentLine(
        totalRepeatHyphens: number = TotalFunctionSeparatorChars): CodeBuilder {
        return this.appendCommentLine('-'.repeat(totalRepeatHyphens));
    }

    public appendCommentLine(commentLine?: string): CodeBuilder {
        this.lines.push(`${this.getCommentDelimiter()} ${commentLine}`);
        return this;
    }

    public appendFunction(name: string, code: string): CodeBuilder {
        if (!name)  { throw new Error('name cannot be empty or null'); }
        if (!code)  { throw new Error('code cannot be empty or null'); }
        return this
            .appendCommentLineWithHyphensAround(name)
            .appendLine(this.writeStandardOut(`--- ${name}`))
            .appendLine(code)
            .appendTrailingHyphensCommentLine();
    }

    public appendCommentLineWithHyphensAround(
        sectionName: string,
        totalRepeatHyphens: number = TotalFunctionSeparatorChars): CodeBuilder {
        if (!sectionName)  { throw new Error('sectionName cannot be empty or null'); }
        if (sectionName.length >= totalRepeatHyphens) {
            return this.appendCommentLine(sectionName);
        }
        const firstHyphens = '-'.repeat(Math.floor((totalRepeatHyphens - sectionName.length) / 2));
        const secondHyphens = '-'.repeat(Math.ceil((totalRepeatHyphens - sectionName.length) / 2));
        return this
            .appendTrailingHyphensCommentLine()
            .appendCommentLine(firstHyphens + sectionName + secondHyphens)
            .appendTrailingHyphensCommentLine(TotalFunctionSeparatorChars);
    }

    public toString(): string {
        return this.lines.join(NewLine);
    }

    protected abstract getCommentDelimiter(): string;
    protected abstract writeStandardOut(text: string): string;
}