module.exports = (Filter, Tag) =>
    function render(tokens, ctx) {
        var html = '';
        for (var i = 0; i < tokens.length; i++) {
            var token = tokens.shift();
            switch (token.type) {
                case 'html':
                    html += token.value;
                    break;
                case 'output':
                    html += renderOutput(token);
                    break;
                case 'tag':
                    html += renderTag(token);
                    break;
                default:
                    throw new Error(`unexpected type: ${token.type}`);
            }
        }
        return html;

        function renderOutput(token) {
            var filters = token.value.split('|');
            var val = ctx.get(filters.shift());
            return filters
                .map(str => Filter.parse(str))
                .reduce((v, filter) => filter.render(v, ctx), val);
        }

        function renderTag(token) {
            var tag = Tag.parse(token.value),
                subTokens = [];
            if (tag.needClose) {
                var curToken, endToken = 'end' + tag.name;
                while ((curToken = tokens.shift()).value !== endToken) {
                    subTokens.push(curToken);
                }
                if (curToken.value !== endToken) {
                    throw new Error(`${token.value} not closed`);
                }
            }
            return tag.render(subTokens, ctx);
        }
    };