#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include "libmbpk.h"
#include "ini.h"
#include <sys/stat.h>
#include <curl/curl.h>

#define MBPK_DB_DIR "/var/lib/mbpk"
#define MBPK_REPO_DIR "/var/lib/mbpk-repo"
#define MBPK_REPO_CONFIG "/etc/mbpk-repos.ini"
#define MAX_REPOS 32

typedef struct {
	const char *name;
	const char *desc;
	const char *url;
	char **packages;
} mbpk_repository;

struct curl_memory {
	char* memory;
	size_t size;
};

mbpk_repository *repos[MAX_REPOS];
int repo_count = 0;

static char* strdup(const char *s) {
	size_t size = strlen(s) + 1;
	char* p = (char*)malloc(size);
	if (p) {
		memcpy(p, s, size);
	}
	return p;
}

static size_t curl_memory_write_calback(void *contents, size_t size, size_t nmemb, void *userp) {
	size_t realsize = size * nmemb;
	struct curl_memory *mem = (struct curl_memory*)userp;

	char *ptr = realloc(mem->memory, mem->size + realsize + 1);
	if (!ptr) {
		return 0;
	}

	mem->memory = ptr;
	memcpy(&(mem->memory[mem->size]), contents, realsize);
	mem->size += realsize;
	mem->memory[mem->size] = 0;

	return realsize;
}

int mbpk_init(void) {
	CURLcode result;
	struct stat st;
	if (stat(MBPK_DB_DIR, &st) == -1) {
		if (mkdir(MBPK_DB_DIR, 0755) == -1) {
			return MBPK_DB_FAIL;
		}
	}
	if (stat(MBPK_REPO_DIR, &st) == -1) {
		if (mkdir(MBPK_REPO_DIR, 0755) == -1) {
			return MBPK_REPO_FAIL;
		}
	}
	result = curl_global_init(CURL_GLOBAL_ALL);
	if (result != CURLE_OK) {
		return MBPK_CURL_INIT_FAIL;
	}
	return MBPK_OK;
}

static int repo_conf_handler(void* user, const char* section, const char* name, const char* value) {
	if (!(strcmp(name, "url") == 0)) {
		return 0; /* unknown name, error */
	}

	if (repo_count >= MAX_REPOS) {
		return 0; /* too many repos */
	}

	repos[repo_count] = malloc(sizeof(mbpk_repository));
	if (repos[repo_count] == NULL) {
		return 0; /* out of memory */
	}

	repos[repo_count]->name = strdup(section);
	repos[repo_count]->desc = NULL; /* mbpk_update_repositories will fill this in later */
	repos[repo_count]->url = strdup(value);
	repos[repo_count]->packages = NULL; /* mbpk_update_repositories will fill this in later */

	if (repos[repo_count]->name == NULL || repos[repo_count]->url == NULL) {
		free((void*)repos[repo_count]->name);
		free((void*)repos[repo_count]->url);
		free(repos[repo_count]);
		repos[repo_count] = NULL;
		return 0; /* out of memory */
	}

	repo_count++;
	return 1;
}

int mbpk_update_repositories(void) {
	/* Declarations */
	struct stat st;
	int i;
	mbpk_repository *repo;
	CURL* curl;
	CURLcode result;
	char *repo_ini_url;
	char *repo_ini_path;
	char *repo_dir;
	size_t dir_len;
	struct curl_memory chunk;

	repo_count = 0;
	if (ini_parse(MBPK_REPO_CONFIG, repo_conf_handler, NULL) < 0) {
		return MBPK_REPO_FAIL;
	}

	for (i = 0; i < repo_count; i++) {
		repo = repos[i];
		printf("[libmbpk debug] processing repo %s\n", repo->name);
		chunk.memory = malloc(1);
		if (!chunk.memory) {
			return MBPK_OUT_OF_MEMORY;
		}
		chunk.size = 0;

		curl = curl_easy_init();
		if (curl) {
			repo_ini_url = malloc(strlen(repo->url) + strlen("/repo.ini") + 1);
			if (!repo_ini_url) {
				return MBPK_OUT_OF_MEMORY;
			}
			strcpy(repo_ini_url, repo->url);
			strcat(repo_ini_url, "/repo.ini");
			printf("[libmbpk debug] URL: %s\n", repo_ini_url);
			printf("[libmbpk debug] repo url field: %s\n", repo->url);
			curl_easy_setopt(curl, CURLOPT_URL, repo_ini_url);
			curl_easy_setopt(curl, CURLOPT_FOLLOWLOCATION, 1L); /* follow redirects */
			curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, curl_memory_write_calback);
			curl_easy_setopt(curl, CURLOPT_WRITEDATA, (void*)&chunk);

			result = curl_easy_perform(curl);
			curl_easy_cleanup(curl);
			free(repo_ini_url);

			if (result != CURLE_OK) {
				printf("[libmbpk debug] perform cURL failed\n");
				free(chunk.memory);
				return MBPK_CURL_PERFORM_FAIL;
			} else {
				printf("[libmbpk debug] %lu bytes received\n", (unsigned long)chunk.size);
				printf("[libmbpk debug] Response:\n%s\n", chunk.memory);
			}
		} else {
			free(chunk.memory);
			return MBPK_CURL_INIT_FAIL;
		}
		
		dir_len = strlen(MBPK_REPO_DIR) + 1 + strlen(repo->name) + 1;
		repo_dir = malloc(dir_len);

		free(chunk.memory);
	}

	return MBPK_OK;
}

void mbpk_cleanup(void) {	
	int i;
	for (i = 0; i < repo_count; i++) {
		if (repos[i]) {
			free((void*)repos[i]->name);
			free((void*)repos[i]->url);
			free((void*)repos[i]->desc);
			free((void*)repos[i]->packages);
			free((void*)repos[i]);
			repos[i] = NULL;
		}
	}
	repo_count = 0;
	curl_global_cleanup();
}

const char* mbpk_strerr(int code) {
	const char* strerr;
	switch (code) {
		case MBPK_OK:
			strerr = "MBPK_OK (0)";
			break;
		case MBPK_DB_FAIL:
			strerr = "MBPK_DB_FAIL (1)";
			break;
		case MBPK_REPO_FAIL:
			strerr = "MBPK_REPO_FAIL (2)";
			break;
		case MBPK_DL_FAIL:
			strerr = "MBPK_DL_FAIL (3)";
			break;
		case MBPK_EXTRACT_FAIL:
			strerr = "MBPK_EXTRACT_FAIL (4)";
			break;
		case MBPK_CURL_INIT_FAIL:
			strerr = "MBPK_CURL_INIT_FAIL (5)";
			break;
		case MBPK_CURL_PERFORM_FAIL:
			strerr = "MBPK_CURL_PERFORM_FAIL (6)";
			break;
		case MBPK_OUT_OF_MEMORY:
			strerr = "MBPK_OUT_OF_MEMORY (7)";
			break;
		default:
			strerr = "MBPK_UNKNOWN_ERR";
			break;
	}
	return strerr;
}