import * as vscode from 'vscode';
import { FormatState } from './formatters/FormatState';
import { IndentationRules } from './formatters/IndentationRules';
import { AlignmentRules } from './formatters/AlignmentRules';

export class TplDocumentFormatter implements vscode.DocumentFormattingEditProvider {
    private indentRules = new IndentationRules();
    private alignRules = new AlignmentRules();

    public provideDocumentFormattingEdits(
        document: vscode.TextDocument, 
        options: vscode.FormattingOptions, 
        token: vscode.CancellationToken
    ): vscode.ProviderResult<vscode.TextEdit[]> {
        
        const edits: vscode.TextEdit[] = [];
        const state = new FormatState();
        
        // Nutze die VS Code Settings (meist 4 Spaces), andernfalls Fallback
        state.tabSize = options.tabSize || 4;

        for (let i = 0; i < document.lineCount; i++) {
            const originalLine = document.lineAt(i);
            const rawText = originalLine.text;
            const trimmedText = rawText.trim();

            // Leere Zeilen lassen wir leer
            if (trimmedText.length === 0) {
                if (rawText.length > 0) {
                    // Löscht unnötige Whitespaces in eigentlich leeren Zeilen
                    edits.push(vscode.TextEdit.replace(originalLine.range, ''));
                }
                continue; 
            }

            // 1. Basis-Einrückung (if/else/pattern) berechnen
            let formattedText = this.indentRules.apply(trimmedText, state);

            // 2. Visual Alignment (Klammern) anwenden & Stack updaten
            formattedText = this.alignRules.apply(trimmedText, formattedText, state);

            // 3. Edit nur erstellen, wenn sich die Zeile wirklich ändert (spart Performance & Cursor-Sprünge)
            if (rawText !== formattedText) {
                edits.push(vscode.TextEdit.replace(originalLine.range, formattedText));
            }
        }

        return edits;
    }
}