#include "ctx.h"

#include <ivy/lang/ast.h>

static bool parse_block_params(
	struct ivy_parser *parser, struct ivy_ast_block_node *block)
{
	while (1) {
		if (parse_symbol(parser, IVY_SYM_PIPE)) {
			break;
		}

		if (!parse_symbol(parser, IVY_SYM_COLON)) {
			parse_trace(
				parser,
				"expected `|`, or `:` followed by parameter "
				"name");
			return false;
		}

		struct ivy_token *ident = NULL;
		if (!parse_word(parser, &ident)) {
			parse_trace(
				parser,
				"expected parameter identifier after `:`");
			return false;
		}

		struct ivy_ast_ident_node *ident_node = create_node(IVY_AST_IDENT);
		ident_node->n_content = ident;
		fx_queue_push_back(&block->n_arg, &ident_node->n_base.n_entry);
	}

	return true;
}

bool parse_block(struct ivy_parser *parser, struct ivy_ast_node **out)
{
	if (!parse_symbol(parser, IVY_SYM_LEFT_BRACKET)) {
		parse_trace(parser, "expected `[` before block contents");
		return false;
	}

	struct ivy_ast_block_node *block = create_node(IVY_AST_BLOCK);
	if (!block) {
		parser->p_status = IVY_ERR_NO_MEMORY;
		return false;
	}

	bool result = true;

	if (peek_symbol(parser, IVY_SYM_COLON)) {
		result = parse_block_params(parser, block);
	}

	if (!result) {
		parse_trace(parser, "invalid block parameter list");
		return false;
	}

	bool prev_was_expr = false;

	while (1) {
		struct ivy_ast_node *child = NULL;
		if (parse_linefeed(parser)) {
			continue;
		}

		if (parse_symbol(parser, IVY_SYM_RIGHT_BRACKET)) {
			break;
		}

		if (prev_was_expr) {
			if (!parse_symbol(parser, IVY_SYM_DOT)) {
				parse_trace(
					parser,
					"expected `.` after expression");
				result = false;
				break;
			}

			prev_was_expr = false;
			continue;
		}

		if (peek_expr_start(parser)) {
			result = parse_expr(parser, EXPR_PARSE_NORMAL, &child);
			prev_was_expr = true;
		} else {
			parse_trace(parser, "expected `]` or expression");
			result = false;
		}

		if (!result || !child) {
			break;
		}

		fx_queue_push_back(&block->n_expr, &child->n_entry);
	}

	*out = generic_node(block);
	return result;
}