#include "config.h"
#include <stdio.h>
#include <stdlib.h>
#include <stdbool.h>
#include <unistd.h>
#include <string.h>
#include "global.h"
#include "alternative.h"
#include "libstr.h"
#include "libfs.h"
#ifdef HAVE_REWRITE
#include "rewrite.h"
#endif

#define MAX_INPUT KILOBYTE

typedef struct type_line {
	char *key, *value, *file;
	int linenr;
	struct type_line *next;
} t_line;

bool quiet = false;

int read_file(char *config_file, t_line **config, t_line **aliases, bool handle_include);

t_line *last_result(t_line *config) {
	if (config != NULL) {
		while (config->next != NULL) {
			config = config->next;
		}
	}
	
	return config;
}

int add_result(t_line **config, char *key, char *value, char *file, int linenr) {
	t_line *new;

	if (*config == NULL) {
		if ((new = *config = (t_line*)malloc(sizeof(t_line))) == NULL) {
			return -1;
		}
	} else {
		new = last_result(*config);
		if ((new->next = (t_line*)malloc(sizeof(t_line))) == NULL) {
			return -1;
		}
		new = new->next;
	}
	new->next = NULL;

	new->key = key;
	new->value = value;
	new->file = file;
	new->linenr = linenr;

	return 0;
}

t_line *search_key(t_line *config, char *key) {
	t_line *result = NULL;

	while (config != NULL) {
		if (strcasecmp(config->key, key) == 0) {
			if (config->value == NULL) {
				printf("'%s' on line %d in '"CONFIG_DIR"/%s' requires a parameter.\n", config->key, config->linenr, config->file);
				exit(EXIT_FAILURE);
			} else if (add_result(&result, config->key, config->value, config->file, config->linenr) != 0) {
				return NULL;
			}
		}
		config = config->next;
	}

	return result;
}

t_line *in_result(char *value, t_line *result) {
	while (result != NULL) {
		if (strcmp(result->value, value) == 0) {
			return result;
		}
		result = result->next;
	}

	return NULL;
}

void dispose_result(t_line *config, bool free_content) {
	t_line *prev;

	while (config != NULL) {
		prev = config;
		config = config->next;

		if (free_content) {
			free(prev->key);
		}
		free(prev);
	}
}

#ifdef DEBUG
void print_file(t_line *line) {
	while (line != NULL) {
		printf("%3d:%-25s [%s] = [%s]\n", line->linenr, line->file, line->key, line->value);
		line = line->next;
	}
}
#endif

int read_directory(char *dir, t_line **config, t_line **aliases) {
	t_filelist *filelist, *file;
	char *path;
	int retval = 0;

	if ((filelist = read_filelist(dir)) == NULL) {
		return -1;
	}
	file = filelist = sort_filelist(filelist);
	
	while (file != NULL) {
		if (strcmp(file->name, "..") != 0) {
			if ((path = make_path(dir, file->name)) != NULL) {
				if (file->is_dir) {
					retval = read_directory(path, config, aliases);
					free(path);
				} else {
					retval = read_file(path, config, aliases, false);
				}

				if (retval == -1) {
					break;
				}
			} else {
				retval = -1;
				break;
			}
		}
		file = file->next;
	}
	remove_filelist(filelist);

	return retval;
}

int read_file(char *config_file, t_line **config, t_line **aliases, bool handle_include) {
	FILE *fp;
	char line[MAX_INPUT + 1], *data, *value;
	bool is_alias;
	int linenr = 0, retval = 0;

	if (quiet == false) {
		printf("Reading %s\n", config_file);
	}

	if ((fp = fopen(config_file, "r")) == NULL) {
		perror(config_file);
		return -1;
	}

	line[MAX_INPUT] = '\0';
	while (fgets(line, MAX_INPUT, fp) != NULL) {
		linenr++;
		data = strip_line(line);
		if ((data[0] == '#') || (data[0] == '\0')) {
			continue;
		}

		if (handle_include && (strncasecmp(data, "include ", 8) == 0)) {
			switch (is_directory(data + 8)) {
				case no:
					retval = read_file(strdup(data + 8), config, aliases, false);
					break;
				case yes:
					retval = read_directory(data + 8, config, aliases);
					break;
				default:
					retval = -1;
			}
		} else {
			if (strncmp(data, "set ", 4) == 0) {
				is_alias = true;
				data += 4;
			} else {
				is_alias = false;
			}

			data = strdup(data);
			split_configline(data, &data, &value);
			if (is_alias) {
				retval = add_result(aliases, data, value, config_file, linenr);
			} else {
				retval = add_result(config, strlower(data), value, config_file, linenr);
			}
		}

		if (retval == -1) {
			break;
		}
	}
	fclose(fp);

	return retval;
}

int read_config_file(char *config_file, t_line **config) {
	t_line *aliases = NULL, *alias, *line;
	char *new_value;
	int retval;

	if ((retval = read_file(config_file, config, &aliases, true)) == -1) {
		return -1;
	}

	/* Replace the aliasses
	 */
	line = *config;
	while (line != NULL) {
		alias = aliases;
		while (alias != NULL) {
			if (line->value != NULL) {
				if (str_replace(line->value, alias->key, alias->value, &new_value) > 0) {
					line->value = new_value;
				}
			}
			alias = alias->next;
		}
		line = line->next;
	}
	dispose_result(aliases, true);

	return retval;
}

bool is_ip_address(char *str) {
	char *digit;
	int digits = 0, value;

	while (str != NULL) {
		split_string(str, &digit, &str, '.');
		value = str2int(digit);
		if ((value < 0) || (value > 255)) {
			return false;
		}
		digits++;
	}

	return (digits == 4);
}

int find_duplicates(t_line *config, char *key, char *config_dir) {
	t_line *haystack, *needles, *needle;
	int errors = 0;

	haystack = needles = search_key(config, key);
	while (needles != NULL) {
		if ((needle = in_result(needles->value, needles->next)) != NULL) {
			printf("Duplicate %s found on line %d in '%s/%s'.\n", key, needle->linenr, config_dir, needle->file);
			errors++;
		}
		needles = needles->next;
	}
	dispose_result(haystack, false);

	return errors;
}

int check_main_config(char *config_dir) {
	int errors = 0;
	t_line *config = NULL, *haystack, *needles, *needle;
	char *item, *rest, *info;
	bool inside_section, has_dot;

	if (quiet == false) {
		printf("Using %s\n", config_dir);
	}

	if (chdir(config_dir) == -1) {
		perror(config_dir);
		return 1;
	}

	/* Read the configuration file
	 */
	config = NULL;
	if (read_config_file(strdup("httpd.conf"), &config) != 0) {
		return 1;
	}

	/* Find duplicate ids
	 */
	errors += find_duplicates(config, "BindingId", config_dir);
	errors += find_duplicates(config, "FastCGIid", config_dir);
	errors += find_duplicates(config, "RewriteId", config_dir);

	/* Binding Id check
	 */
	haystack = search_key(config, "bindingid");
	needles = needle = search_key(config, "requiredbinding");
	while (needle != NULL) {
		rest = strdup(needle->value);
		while (rest != NULL) {
			split_string(rest, &item, &rest, ',');
			if (in_result(item, haystack) == NULL) {
				printf("RequiredBinding '%s' on line %d in '%s/%s' not found in Binding section.\n", item, needle->linenr, config_dir, needle->file);
				errors++;
			}
		}
		free(rest);
		needle = needle->next;
	}
	dispose_result(haystack, false);
	dispose_result(needles, false);

	/* FastCGI Id check
	 */
	haystack = search_key(config, "fastcgiid");
	needles = needle = search_key(config, "fastcgi");
	while (needle != NULL) {
		rest = strdup(needle->value);
		while (rest != NULL) {
			split_string(rest, &item, &rest, ',');
			if (in_result(item, haystack) == NULL) {
				printf("FastCGIid '%s' on line %d in '%s/%s' not found in FastCGIserver section.\n", needle->value, needle->linenr, config_dir, needle->file);
				errors++;
			}
		}
		free(rest);
		needle = needle->next;
	}
	dispose_result(haystack, false);
	dispose_result(needles, false);

	/* Rewrite Id check
	 */
	haystack = search_key(config, "rewriteid");
	needles = needle = search_key(config, "rewriteurl");
	while (needle != NULL) {
		rest = strdup(needle->value);
		while (rest != NULL) {
			split_string(rest, &item, &rest, ',');
			if (in_result(item, haystack) == NULL) {
				printf("RewriteURL '%s' on line %d in '%s/%s' not found in UrlRewrite section.\n", item, needle->linenr, config_dir, needle->file);
				errors++;
			}
		}
		free(rest);
		needle = needle->next;
	}
	dispose_result(haystack, false);
	dispose_result(needles, false);

	/* Extension check
	 */
	haystack = NULL;
	needles = needle = search_key(config, "cgiextension");
	while (needle != NULL) {
		rest = strdup(needle->value);
		while (rest != NULL) {
			split_string(rest, &item, &rest, ',');
			if (in_result(item, haystack) == NULL) {
				add_result(&haystack, needle->key, item, needle->file, needle->linenr);
			} else {
				printf("Duplicate extension (%s) found in CGIextension.\n", item);
				errors++;
			}
		}
		needle = needle->next;
	}
	dispose_result(needles, false);

	needles = needle = search_key(config, "cgihandler");
	while (needle != NULL) {
#ifdef CYGWIN
		if ((rest = strstr(needle->value, ":\\")) != NULL) {
			rest += 2;
		} else
#endif
			rest = strdup(needle->value);
		split_string(rest, &info, &rest, ':');
#ifdef CYGWIN
		info = needle->value;
#endif
		while (rest != NULL) {
			split_string(rest, &item, &rest, ',');
			if (in_result(item, haystack) == NULL) {
				add_result(&haystack, needle->key, item, needle->file, needle->linenr);
			} else {
				printf("Duplicate extension (%s) found in CGIhandler %s.\n", item, info);
				errors++;
			}
		}
		needle = needle->next;
	}
	dispose_result(needles, false);

	dispose_result(haystack, false);

	/* Default-website hostname check (non-fatal)
	 */
	inside_section = false;
	haystack = config;
	while (haystack != NULL) {
		if (strncmp(haystack->key, "virtualhost", 11) == 0) {
			inside_section = true;
		} else if (strcmp(haystack->key, "}") == 0) {
			inside_section = false;
		} else if (inside_section == false) {
			if (strcmp(haystack->key, "hostname") == 0) {
				if (is_ip_address(haystack->value) == false) {
					printf("Warning: it is wise to use your IP address as the hostname of the default website (line %d in '%s/%s') and give it a blank webpage. By doing so, automated webscanners won't find your possible vulnerable website.\n", haystack->linenr, config_dir, haystack->file);
				}
				break;
			}
		}

		haystack = haystack->next;
	}

	/* Check for dots in extensios
	 */
	haystack = config;
	while (haystack != NULL) {
		if ((strcmp(haystack->key, "cgiextension") == 0) || (strcmp(haystack->key, "extension") == 0)) {
			has_dot = (strchr(haystack->value, '.') != NULL);
		} else if (strcmp(haystack->key, "cgihandler") == 0) {
#ifdef CYGWIN
			if ((info = strstr(haystack->value, ":\\")) != NULL) {
				info += 2;
			} else
#endif
				info = haystack->value;
			if ((rest = strchr(info, ':')) != NULL) {
				has_dot = (strchr(rest, '.') != NULL);
			} else {
				has_dot = false;
			}
		} else {
			has_dot = false;
		}

		if (has_dot) {
			printf("Extensions should not contain a dot (line %d in '%s/%s')\n", haystack->linenr, config_dir, haystack->file);
			errors++;
		}

		haystack = haystack->next;
	}

	dispose_result(config, true);

	return errors;
}

#ifdef HAVE_REWRITE
void check_url_rewrite(char *config_dir, char **rewrite_id) {
	t_line *config = NULL;
	char input[MAX_INPUT + 1], **id, *url, *new_url;
	t_url_rewrite *url_rewrite, *rewrite = NULL;
	bool in_rule_section = false;
	int result;

	if (chdir(config_dir) == -1) {
		perror(config_dir);
		return;
	}

	/* Read the configuration file
	 */
	config = NULL;
	if (read_config_file(strdup("httpd.conf"), &config) != 0) {
		return;
	}

	/* Parse the URL rewrite rules
	 */
	url_rewrite = NULL;
	while (config != NULL) {
		if (in_rule_section) {
			if ((strcmp(config->key, "}") == 0) && (strcmp(config->value, "") == 0)) {
				in_rule_section = false;
			} else if (url_rewrite_setting(config->key, config->value, rewrite) == false) {
				fprintf(stderr, "UrlRewrite error in %s on line %d.\n", config->file, config->linenr);
				return;
			}
		} else if ((strcmp(config->key, "urlrewrite") == 0) && (strcmp(config->value, "{") == 0)) {
			if (url_rewrite == NULL) {
				url_rewrite = rewrite = (t_url_rewrite*)malloc(sizeof(t_url_rewrite));
			} else {
				rewrite->next = (t_url_rewrite*)malloc(sizeof(t_url_rewrite));
				rewrite = rewrite->next;
			}
			rewrite->rewrite_id = NULL;
			rewrite->rewrite_rule = NULL;
			rewrite->next = NULL;

			in_rule_section = true;
		}
		config = config->next;
	}

	if (url_rewrite == NULL) {
		printf("No URL rewrite rules found.\n");
		return;
	}

	if (rewrite_rules_oke(url_rewrite) == false) {
		return;
	}

	if (*rewrite_id == NULL) {
		printf("No errors found in URL rewrite rules.\n");
		return;
	} else

	id = rewrite_id;
	do {
		if (find_url_rewrite(*id, url_rewrite) == false) {
			printf("RewriteID '%s' not found.\n", *id);
			return;
		}
		id++;
	} while (*id != NULL);

	/* Start testing
	 */
	input[MAX_INPUT] = '\0';
	printf("\n===[ URL rewrite tester\n");
	printf("Use empty input to leave the program.\n\nurl: ");
	while (fgets(input, MAX_INPUT, stdin) != NULL) {
		url = remove_spaces(input);

		if (strcmp(url, "") == 0) {
			printf("bye!\n\n");
			break;
		}

		id = rewrite_id;
		while (*id != NULL) {
			if ((result = rewrite_url(url, *id, url_rewrite, &new_url)) == RW_ERROR) {
				perror("rewrite_url()");
			}
			if (new_url != NULL) {
				url = new_url;
			}
			if (result == RW_DENY_ACCESS) {
				url = "(403 Forbidden)";
				break;
			}
			id++;
		}

		if (new_url != NULL) {
			printf("new: %s\n\n", new_url);
			free(new_url);
		} else {
			printf("old: %s\n\n", url);
		}

		printf("url: ");
	}
}
#endif

void show_help(char *wigwam) {
	printf("Usage: %s [options]\n", wigwam);
	printf("Options: -c <path>: path to where the configrationfiles are located.\n");
	printf("         -h: show this information and exit.\n");
	printf("         -q: don't print the test results.\n");
#ifdef HAVE_REWRITE
	printf("         -r [<rewrite_id> ...]: test URL rewrite rule(s).\n");
#endif
	printf("         -v: show version and exit.\n");
}

int main(int argc, char *argv[]) {
	int i, errors_found = 0;
	char *config_dir = CONFIG_DIR;

	for (i = 1; i < argc; i++) {
		if (strcmp(argv[i], "-c") == 0) {
			if (++i < argc) {
				config_dir = argv[i];
			} else {
				fprintf(stderr, "Specify a directory.\n");
				return EXIT_FAILURE;
			}
        } else if (strcmp(argv[i], "-h") == 0) {
			show_help(argv[0]);
			return EXIT_SUCCESS;
#ifdef HAVE_REWRITE
		} else if (strcmp(argv[i], "-r") == 0) {
			check_url_rewrite(config_dir, argv + i + 1);
			return EXIT_SUCCESS;
#endif
		} else if (strcmp(argv[i], "-q") == 0) {
			quiet = true;
		} else if (strcmp(argv[i], "-v") == 0) {
			printf("Wigwam v"VERSION"\n");
			return EXIT_SUCCESS;
		} else {
			fprintf(stderr, "Unknown option. Use '-h' for help.\n");
			return EXIT_FAILURE;
		}
	}

	errors_found += check_main_config(config_dir);

	if ((quiet == false) && (errors_found == 0))  {
		printf("No non-fatal errors found in the Hiawatha configuration.\n");
	}

	if (errors_found > 0) {
		return EXIT_FAILURE;
	}

	return EXIT_SUCCESS;
}