#include "ctx.h"

#include <ivy/lang/ast.h>

static bool parse_named_selector(
	struct ivy_parser *parser, struct ivy_ast_selector_node *sel)
{
	struct ivy_token *tok = NULL;
	if (!parse_word(parser, &tok)) {
		parse_trace(NULL, "expected selector name");
		return false;
	}

	sel->n_msg_name = tok;

	if (!parse_symbol(parser, IVY_SYM_LEFT_PAREN)) {
		return true;
	}

	bool ok = true;
	while (1) {
		if (parse_symbol(parser, IVY_SYM_RIGHT_PAREN)) {
			break;
		}

		struct ivy_token *label = NULL, *arg = NULL;
		if (!fx_queue_empty(&sel->n_arg_labels)
		    && !parse_symbol(parser, IVY_SYM_COMMA)) {
			parse_trace(NULL, "expected comma after selector arg");
			ok = false;
			break;
		}

		if (!parse_label(parser, &label)) {
			parse_trace(NULL, "expected selector arg label");
			ok = false;
			break;
		}

		if (!parse_word(parser, &arg)) {
			parse_trace(NULL, "expected selector arg name");
			ok = false;
			break;
		}

		fx_queue_push_back(&sel->n_arg_labels, &label->t_entry);
		fx_queue_push_back(&sel->n_arg_names, &arg->t_entry);
	}

	return true;
}

static bool parse_unnamed_selector(
	struct ivy_parser *parser, struct ivy_ast_selector_node *sel)
{
	bool ok = true;
	while (1) {
		struct ivy_token *label = NULL, *arg = NULL;
		if (!parse_label(parser, &label)) {
			break;
		}

		if (!parse_word(parser, &arg)) {
			parse_trace(NULL, "expected selector arg name");
			ok = false;
			break;
		}

		fx_queue_push_back(&sel->n_arg_labels, &label->t_entry);
		fx_queue_push_back(&sel->n_arg_names, &arg->t_entry);
	}

	return true;
}

static bool parse_selector(struct ivy_parser *parser, struct ivy_ast_node **out)
{
	struct ivy_ast_selector_node *sel = create_node(IVY_AST_SELECTOR);
	if (parse_symbol(parser, IVY_SYM_PLUS)) {
		sel->n_recipient = IVY_SELECTOR_RECIPIENT_CLASS;
	} else if (parse_symbol(parser, IVY_SYM_HYPHEN)) {
		sel->n_recipient = IVY_SELECTOR_RECIPIENT_OBJECT;
	} else {
		parse_trace(NULL, "invalid selector prefix");
		return false;
	}

	bool ok = true;
	if (peek_word(parser)) {
		ok = parse_named_selector(parser, sel);
	} else {
		ok = parse_unnamed_selector(parser, sel);
	}

	if (!ok) {
		return false;
	}

	*out = generic_node(sel);
	return true;
}

static bool parse_msg(struct ivy_parser *parser, struct ivy_ast_node **out)
{
	struct ivy_ast_node *sel = NULL;
	if (!parse_selector(parser, &sel)) {
		parse_trace(NULL, "invalid message handler selector");
		return false;
	}

	struct ivy_ast_msgh_node *msgh = create_node(IVY_AST_MSGH);
	msgh->n_sel = (struct ivy_ast_selector_node *)sel;

	bool ok = true;
	struct ivy_ast_node *body = NULL;
	if (peek_symbol(parser, IVY_SYM_LEFT_BRACKET)) {
		ok = parse_block(parser, &body);
	} else if (parse_symbol(parser, IVY_SYM_PIPE)) {
		ok = parse_expr(parser, EXPR_PARSE_NORMAL, &body);
		ok = ok && parse_symbol(parser, IVY_SYM_DOT);
	} else {
		parse_trace(NULL, "expected message handler body");
		ok = false;
	}

	if (!ok) {
		return false;
	}

	msgh->n_body = body;
	*out = generic_node(msgh);
	return true;
}

static bool parse_default_property(
	struct ivy_parser *parser, struct ivy_ast_property_node *prop)
{
	if (!parse_symbol(parser, IVY_SYM_LEFT_PAREN)) {
		parse_trace(parser, "expected '('");
		return false;
	}

	bool ok = true;
	while (ok) {
		parse_linefeed(parser);

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

		int access_types_set
			= prop->n_flags
		        & (IVY_AST_PROPERTY_SET | IVY_AST_PROPERTY_GET);

		if (access_types_set != 0 && !parse_symbol(parser, IVY_SYM_COMMA)) {
			parse_trace(
				NULL,
				"expected `,` or `)` after property access "
				"type");
			ok = false;
			break;
		}

		parse_linefeed(parser);

		int access_type = 0;
		if (parse_keyword(parser, IVY_KW_GET)) {
			access_type = IVY_AST_PROPERTY_GET;
		} else if (parse_keyword(parser, IVY_KW_SET)) {
			access_type = IVY_AST_PROPERTY_SET;
		} else {
			parse_trace(parser, "unknown property access type");
			ok = false;
			break;
		}

		parse_linefeed(parser);

		if (prop->n_flags & access_type) {
			parse_trace(parser, "property access type already set");
			ok = false;
			break;
		}

		prop->n_flags |= access_type;
	}

	return true;
}

static bool parse_property(struct ivy_parser *parser, struct ivy_ast_node **out)
{
	struct ivy_token *tok = NULL;
	if (!parse_word(parser, &tok)) {
		parse_trace(NULL, "expected property name");
		return false;
	}

	struct ivy_ast_property_node *prop = create_node(IVY_AST_PROPERTY);
	prop->n_ident = tok;

	if (peek_symbol(parser, IVY_SYM_LEFT_PAREN)) {
		return parse_default_property(parser, prop);
	}

	if (!parse_symbol(parser, IVY_SYM_PIPE)) {
		parse_trace(NULL, "expected `|` after property name");
		return false;
	}

	bool ok = true;

	while (ok) {
		if (parse_symbol(parser, IVY_SYM_DOT)) {
			break;
		}

		parse_linefeed(parser);

		if ((prop->n_get || prop->n_set)
		    && !parse_symbol(parser, IVY_SYM_COMMA)) {
			parse_trace(
				NULL,
				"expected `,` or `.` after property "
				"branch");
			ok = false;
			break;
		}

		parse_linefeed(parser);

		int access_type = 0;
		if (parse_keyword(parser, IVY_KW_GET)) {
			access_type = IVY_AST_PROPERTY_GET;
		} else if (parse_keyword(parser, IVY_KW_SET)) {
			access_type = IVY_AST_PROPERTY_SET;
		} else {
			parse_trace(NULL, "unknown property access type");
			ok = false;
			break;
		}

		parse_linefeed(parser);

		if (!parse_symbol(parser, IVY_SYM_EQUAL_RIGHT_ANGLE)) {
			parse_trace(
				NULL,
				"expected `=>` after property branch "
				"type");
			ok = false;
			break;
		}

		parse_linefeed(parser);

		struct ivy_ast_node *body = NULL;
		if (peek_symbol(parser, IVY_SYM_LEFT_BRACKET)) {
			ok = parse_block(parser, &body);
		} else {
			ok = parse_expr(parser, EXPR_PARSE_STOP_COMMA, &body);
		}

		if (!ok) {
			parse_trace(parser, "invalid property value");
			break;
		}

		prop->n_flags |= access_type;
		switch (access_type) {
		case IVY_AST_PROPERTY_GET:
			if (prop->n_get) {
				parse_trace(NULL, "property getter already set");
				ok = false;
				break;
			}

			prop->n_get = body;
			break;
		case IVY_AST_PROPERTY_SET:
			if (prop->n_set) {
				parse_trace(NULL, "property setter already set");
				ok = false;
				break;
			}

			prop->n_set = body;
			break;
		default:
			ok = false;
			break;
		}
	}

	if (!ok) {
		return false;
	}

	*out = generic_node(prop);
	return true;
}

bool parse_class(struct ivy_parser *parser, struct ivy_ast_node **out)
{
	if (!parse_keyword(parser, IVY_KW_CLASS)) {
		return false;
	}

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

	if (!parse_symbol(parser, IVY_SYM_LEFT_BRACKET)) {
		parse_trace(NULL, "expected  `[` after class identifier");
		return false;
	}

	struct ivy_ast_class_node *class = create_node(IVY_AST_CLASS);
	if (!class) {
		parser->p_status = IVY_ERR_NO_MEMORY;
		return false;
	}

	class->n_ident = ident;

	bool result = true;
	while (1) {
		struct ivy_ast_node *msg = NULL, *property = NULL;
		if (parse_linefeed(parser)) {
			continue;
		}

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

		if (peek_symbol(parser, IVY_SYM_HYPHEN)) {
			result = parse_msg(parser, &msg);
		} else if (peek_symbol(parser, IVY_SYM_PLUS)) {
			result = parse_msg(parser, &msg);
		} else if (peek_word(parser)) {
			result = parse_property(parser, &property);
		} else {
			parse_trace(
				parser, "unexpected token %s in class",
				ivy_token_to_string(peek_token(parser)));
			result = false;
		}

		if (!result) {
			break;
		}

		if (msg) {
			fx_queue_push_back(&class->n_msg_handlers, &msg->n_entry);
		} else if (property) {
			fx_queue_push_back(
				&class->n_msg_handlers, &property->n_entry);
		}
	}

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