import * as vscode from 'vscode';
import { TplLookup } from '../core/TplLookup';
import { workspaceIndex } from '../core/WorkspaceIndex';

export class TplHoverProvider implements vscode.HoverProvider {
    public provideHover(document: vscode.TextDocument, position: vscode.Position, token: vscode.CancellationToken): vscode.ProviderResult<vscode.Hover> {
        const range = document.getWordRangeAtPosition(position, /[a-zA-Z0-9_.]+/);
        if (!range) return null;

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

        if (parts.length > 1) {
            // 1. Suche in Core & TKU Built-Ins (Case-Insensitive)
            const funcData = TplLookup.getBuiltInFunction(parts[0], parts[1]);
            if (funcData) {
                const md = new vscode.MarkdownString();
                md.appendCodeblock(`${parts[0]}.${parts[1]}(${funcData.snippets?.[0] || ''})`, 'tpl');
                md.appendMarkdown(`---\n${funcData.description}`);
                return new vscode.Hover(md);
            }
        }

        // 2. Suche in lokalem Workspace (RAM Index)
        const funcName = parts.length > 1 ? parts[1] : word;
        const signatures = workspaceIndex.getFunctionSignatures(funcName);
        if (signatures.length > 0) {
            const sig = signatures[0];
            const md = new vscode.MarkdownString();
            md.appendCodeblock(`define ${sig.name}(${sig.params.join(', ')})`, 'tpl');
            if (sig.docString) {
                md.appendMarkdown(`---\n${sig.docString}`);
            }
            return new vscode.Hover(md);
        }

        return null;
    }
}