import * as vscode from 'vscode';
import { tplBuiltIns } from '../data/TplBuiltIns';

export class TplHoverProvider implements vscode.HoverProvider {
    public async provideHover(
        document: vscode.TextDocument,
        position: vscode.Position,
        token: vscode.CancellationToken
    ): Promise<vscode.Hover | null> {
        
        // Greift das Wort unter dem Mauszeiger ab, inklusive Punkte für Namespaces
        const range = document.getWordRangeAtPosition(position, /[a-zA-Z0-9_.]+/);
        if (!range) {
            return null;
        }

        const word = document.getText(range);
        const parts = word.split('.');

        let namespace = '';
        let methodOrPatternName = '';

        if (parts.length === 2) {
            namespace = parts[0];
            methodOrPatternName = parts[1];
        } else if (parts.length === 1) {
            methodOrPatternName = parts[0];
        } else {
            return null;
        }

        // BMC Namespace-Methoden (z.B. discovery.listDirectory)
        if (namespace && tplBuiltIns[namespace] && tplBuiltIns[namespace][methodOrPatternName]) {
            const def = tplBuiltIns[namespace][methodOrPatternName];
            const markdown = new vscode.MarkdownString();
            markdown.appendCodeblock(`${namespace}.${methodOrPatternName}`, 'tpl');
            markdown.appendMarkdown(`---\n\n${def.description}`);
            return new vscode.Hover(markdown);
        } 
        // BMC Globale Funktionen (z.B. size, datatype)
        else if (!namespace && tplBuiltIns['built_in_globals'] && tplBuiltIns['built_in_globals'][methodOrPatternName]) {
            const def = tplBuiltIns['built_in_globals'][methodOrPatternName];
            const markdown = new vscode.MarkdownString();
            markdown.appendCodeblock(`${methodOrPatternName}`, 'tpl');
            markdown.appendMarkdown(`---\n\n${def.description}`);
            return new vscode.Hover(markdown);
        }

        return null;
    }
}