/* Copyright (c) Pigeonhole authors, see top-level COPYING file */

#include "lib.h"
#include "str.h"
#include "str-sanitize.h"

#include "rfc2822.h"

#include "sieve-common.h"
#include "sieve-ast.h"
#include "sieve-validator.h"
#include "sieve-generator.h"
#include "sieve-binary.h"
#include "sieve-commands.h"
#include "sieve-code.h"
#include "sieve-interpreter.h"

/*
 * Literal arguments
 */

/* Forward declarations */

static bool
arg_number_generate(const struct sieve_codegen_env *cgenv,
		    struct sieve_ast_argument *arg,
		    struct sieve_command *context);
static bool
arg_string_generate(const struct sieve_codegen_env *cgenv,
		    struct sieve_ast_argument *arg,
		    struct sieve_command *context);
static bool
arg_string_list_validate(struct sieve_validator *valdtr,
			 struct sieve_ast_argument **arg,
			 struct sieve_command *context);
static bool
arg_string_list_generate(const struct sieve_codegen_env *cgenv,
			 struct sieve_ast_argument *arg,
			 struct sieve_command *context);

/* Argument objects */

const struct sieve_argument_def number_argument = {
	.identifier = "@number",
	.generate = arg_number_generate
};

const struct sieve_argument_def string_argument = {
	.identifier = "@string",
	.generate = arg_string_generate
};

const struct sieve_argument_def string_list_argument = {
	.identifier = "@string-list",
	.validate = arg_string_list_validate,
	.generate = arg_string_list_generate
};

/* Argument implementations */

static bool
arg_number_generate(const struct sieve_codegen_env *cgenv,
		    struct sieve_ast_argument *arg,
		    struct sieve_command *cmd ATTR_UNUSED)
{
	sieve_opr_number_emit(cgenv->sblock, sieve_ast_argument_number(arg));
	return TRUE;
}

static bool
arg_string_generate(const struct sieve_codegen_env *cgenv,
		    struct sieve_ast_argument *arg,
		    struct sieve_command *cmd ATTR_UNUSED)
{
	sieve_opr_string_emit(cgenv->sblock, sieve_ast_argument_str(arg));
	return TRUE;
}

static bool
arg_string_list_validate(struct sieve_validator *valdtr,
			 struct sieve_ast_argument **arg,
			 struct sieve_command *cmd)
{
	struct sieve_ast_argument *stritem;

	stritem = sieve_ast_strlist_first(*arg);
	while (stritem != NULL) {
		if (!sieve_validator_argument_activate(valdtr, cmd,
						       stritem, FALSE))
			return FALSE;

		stritem = sieve_ast_strlist_next(stritem);
	}
	return TRUE;
}

static bool
emit_string_list_operand(const struct sieve_codegen_env *cgenv,
			 const struct sieve_ast_argument *strlist,
			 struct sieve_command *cmd)
{
	void *list_context;
	struct sieve_ast_argument *stritem;

	sieve_opr_stringlist_emit_start(cgenv->sblock,
					sieve_ast_strlist_count(strlist),
					&list_context);

	stritem = sieve_ast_strlist_first(strlist);
	while (stritem != NULL) {
		if (!sieve_generate_argument(cgenv, stritem, cmd))
			return FALSE;

		stritem = sieve_ast_strlist_next(stritem);
	}

	sieve_opr_stringlist_emit_end(cgenv->sblock, list_context);
	return TRUE;
}

static bool
arg_string_list_generate(const struct sieve_codegen_env *cgenv,
			 struct sieve_ast_argument *arg,
			 struct sieve_command *cmd)
{
	if (sieve_ast_argument_type(arg) == SAAT_STRING) {
		return sieve_generate_argument(cgenv, arg, cmd);
	} else if (sieve_ast_argument_type(arg) == SAAT_STRING_LIST) {
		bool result = TRUE;

		if (sieve_ast_strlist_count(arg) == 1) {
			return sieve_generate_argument(
				cgenv, sieve_ast_strlist_first(arg), cmd);
		} else T_BEGIN {
			result = emit_string_list_operand(cgenv, arg, cmd);
		} T_END;

		return result;
	}
	return FALSE;
}

/*
 * Abstract arguments
 *
 *   (Generated by processing and not by parsing the grammar)
 */

/* Catenated string */

struct sieve_arg_catenated_string {
	struct sieve_ast_arg_list *str_parts;
};

struct sieve_arg_catenated_string *
sieve_arg_catenated_string_create(struct sieve_ast_argument *orig_arg)
{
	pool_t pool = sieve_ast_pool(orig_arg->ast);
	struct sieve_ast_arg_list *arglist;
	struct sieve_arg_catenated_string *catstr;

	arglist = sieve_ast_arg_list_create(pool);

	catstr = p_new(pool, struct sieve_arg_catenated_string, 1);
	catstr->str_parts = arglist;
	(orig_arg)->argument->data = catstr;

	return catstr;
}

void sieve_arg_catenated_string_add_element(
	struct sieve_arg_catenated_string *catstr,
	struct sieve_ast_argument *element)
{
	i_assert(catstr->str_parts != NULL);
	sieve_ast_arg_list_add(catstr->str_parts, element);
}

#define _cat_string_first(catstr) __AST_LIST_FIRST((catstr)->str_parts)
#define _cat_string_count(catstr) __AST_LIST_COUNT((catstr)->str_parts)
#define _cat_string_next(item) __AST_LIST_NEXT(item)

bool sieve_arg_catenated_string_generate(const struct sieve_codegen_env *cgenv,
					 struct sieve_ast_argument *arg,
					 struct sieve_command *cmd)
{
	struct sieve_arg_catenated_string *catstr =
		(struct sieve_arg_catenated_string *)arg->argument->data;
	struct sieve_ast_argument *strpart;

	if (_cat_string_count(catstr) == 1)
		sieve_generate_argument(cgenv, _cat_string_first(catstr), cmd);
	else {
		sieve_opr_catenated_string_emit(cgenv->sblock,
						_cat_string_count(catstr));

		strpart = _cat_string_first(catstr);
		while (strpart != NULL) {
			if (!sieve_generate_argument(cgenv, strpart, cmd))
				return FALSE;

			strpart = _cat_string_next(strpart);
		}
	}
	return TRUE;
}

/*
 * Argument creation
 */

struct sieve_argument *
sieve_argument_create(struct sieve_ast *ast,
		      const struct sieve_argument_def *def,
		      const struct sieve_extension *ext, int id_code)
{
	struct sieve_argument *arg;
	pool_t pool;

	pool = sieve_ast_pool(ast);
	arg = p_new(pool, struct sieve_argument, 1);
	arg->def = def;
	arg->ext = ext;
	arg->id_code = id_code;

	return arg;
}

/*
 * Core tests and commands
 */

const struct sieve_command_def *sieve_core_tests[] = {
	&tst_false, &tst_true,
	&tst_not, &tst_anyof, &tst_allof,
	&tst_address, &tst_header, &tst_exists, &tst_size
};

const unsigned int sieve_core_tests_count = N_ELEMENTS(sieve_core_tests);

const struct sieve_command_def *sieve_core_commands[] = {
	&cmd_require,
	&cmd_stop, &cmd_if, &cmd_elsif, &cmd_else,
	&cmd_keep, &cmd_discard, &cmd_redirect
};

const unsigned int sieve_core_commands_count = N_ELEMENTS(sieve_core_commands);

/*
 * Command context
 */

struct sieve_command *sieve_command_prev(struct sieve_command *cmd)
{
	struct sieve_ast_node *node = sieve_ast_node_prev(cmd->ast_node);

	if (node != NULL)
		return node->command;
	return NULL;
}

struct sieve_command *sieve_command_parent(struct sieve_command *cmd)
{
	struct sieve_ast_node *node = sieve_ast_node_parent(cmd->ast_node);

	return (node != NULL ? node->command : NULL);
}

struct sieve_command *
sieve_command_create(struct sieve_ast_node *cmd_node,
		     const struct sieve_extension *ext,
		     const struct sieve_command_def *cmd_def,
		     struct sieve_command_registration *cmd_reg)
{
	struct sieve_command *cmd;

	cmd = p_new(sieve_ast_node_pool(cmd_node), struct sieve_command, 1);

	cmd->ast_node = cmd_node;
	cmd->def = cmd_def;
	cmd->ext = ext;
	cmd->reg = cmd_reg;

	cmd->block_exit_command = NULL;

	return cmd;
}

const char *sieve_command_def_type_name(const struct sieve_command_def *cmd_def)
{
	switch (cmd_def->type) {
	case SCT_NONE:
		return "command of unspecified type (bug)";
	case SCT_TEST:
		return "test";
	case SCT_COMMAND:
		return "command";
	case SCT_HYBRID:
		return "command or test";
	default:
		break;
	}
	return "??COMMAND-TYPE??";
}

const char *sieve_command_type_name(const struct sieve_command *cmd)
{
	switch (cmd->def->type) {
	case SCT_NONE:
		return "command of unspecified type (bug)";
	case SCT_TEST:
		return "test";
	case SCT_COMMAND:
		return "command";
	case SCT_HYBRID:
		if (cmd->ast_node->type == SAT_TEST)
			return "test";
		return "command";
	default:
		break;
	}
	return "??COMMAND-TYPE??";
}

struct sieve_ast_argument *
sieve_command_add_dynamic_tag(struct sieve_command *cmd,
			      const struct sieve_extension *ext,
			      const struct sieve_argument_def *tag,
			      int id_code)
{
	struct sieve_ast_argument *arg;

	if (cmd->first_positional != NULL) {
		arg = sieve_ast_argument_tag_insert(cmd->first_positional,
						    tag->identifier,
						    cmd->ast_node->source_line);
	} else {
		arg = sieve_ast_argument_tag_create(cmd->ast_node,
						    tag->identifier,
						    cmd->ast_node->source_line);
	}

	arg->argument = sieve_argument_create(cmd->ast_node->ast, tag, ext,
					      id_code);
	return arg;
}

struct sieve_ast_argument *
sieve_command_find_argument(struct sieve_command *cmd,
			    const struct sieve_argument_def *arg_def)
{
	struct sieve_ast_argument *arg =
		sieve_ast_argument_first(cmd->ast_node);

	/* Visit tagged and optional arguments */
	while (arg != NULL) {
		if (arg->argument != NULL && arg->argument->def == arg_def)
			return arg;

		arg = sieve_ast_argument_next(arg);
	}
	return arg;
}

/* Use this function with caution. The command commits to exiting the block.
   When it for some reason does not, the interpretation will break later on,
   because exiting jumps are not generated when they would otherwise be
   necessary.
 */
void sieve_command_exit_block_unconditionally(struct sieve_command *cmd)
{
	struct sieve_command *parent = sieve_command_parent(cmd);

	/* Only the first unconditional exit is of importance */
	if (parent != NULL && parent->block_exit_command == NULL)
		parent->block_exit_command = cmd;
}

bool sieve_command_block_exits_unconditionally(struct sieve_command *cmd)
{
	return ( cmd->block_exit_command != NULL );
}

/*
 * Command utility functions
 */

/* NOTE: this may be moved */

static int
_verify_header_name_item(void *context, struct sieve_ast_argument *header)
{
	struct sieve_validator *valdtr = (struct sieve_validator *)context;
	string_t *name = sieve_ast_argument_str(header);

	if (sieve_argument_is_string_literal(header) &&
	    !rfc2822_header_field_name_verify(str_c(name), str_len(name))) {
		sieve_argument_validate_warning(
			valdtr, header,
			"specified header field name '%s' is invalid",
			str_sanitize(str_c(name), 80));
		return 0;
	}
	return 1;
}

bool sieve_command_verify_headers_argument(struct sieve_validator *valdtr,
					   struct sieve_ast_argument *headers)
{
	return (sieve_ast_stringlist_map(&headers, valdtr,
					 _verify_header_name_item) >= 0);
}
