'use strict';
import * as vscode from 'vscode';
import { parseTree, Node } from 'jsonc-parser'

export function activate(context: vscode.ExtensionContext) {

    context.subscriptions.push(vscode.languages.registerDocumentSymbolProvider('json2', {
        provideDocumentSymbols(doc: vscode.TextDocument) {
            let node = parseTree(doc.getText());
            if (node) {
                return createDocumentSymbols(node, doc);
            }
            return null;
        }
    }));
}

function createDocumentSymbols(objectNode: Node, doc: vscode.TextDocument): vscode.DocumentSymbol[] {
    if (objectNode.type === 'object') {
        if (objectNode.children) {
            return objectNode.children.map(node => {
                let nameNode = node.children![0];
                let name = nameNode.value.toString();
                let nameRange = new vscode.Range(doc.positionAt(nameNode.offset), doc.positionAt(nameNode.offset + nameNode.length));
                let range = new vscode.Range(doc.positionAt(node.offset), doc.positionAt(node.offset + node.length));
                let symbol = new vscode.DocumentSymbol(name, `property at ${node.offset}`, vscode.SymbolKind.Property, range, nameRange);

                let valueNode = node.children![1];
                if (valueNode.type === 'object') {
                    symbol.children = createDocumentSymbols(valueNode, doc);
                }
                return symbol;
            });
        }
    }
    return [];
}