#include <stdio.h>
#include <stdbool.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>

#define PKG_DB "../snaggies"
#define PKG_INFO_CMD "./snagpkginfo.sh"

typedef struct {
	char* id;
	char* name;
	char* desc;
	char* script_path;
} package_info_t;

void subcmd_install(char* pkgs[], size_t count);
bool load_package_info(package_info_t* info, char* pkgid);

int main(int argc, char* argv[]) {

	// run install subcommand with each argument as a package
	subcmd_install(argv+1, argc-1);

	return 0;
}

void subcmd_install(char* pkgs[], size_t count) {

	// install each package listed
	for (int i = 0; i < count; ++i) {

		char* pkgid = pkgs[i];

		// load package description
		package_info_t info;
		if (load_package_info(&info, pkgid)) {
			printf("Installing '%s'\n", info.name);
		}
	}
}

bool load_package_info(package_info_t* info, char* pkgid) {

	// construct package description directory path and ensure it exists
	size_t pkg_dir_len = strlen(PKG_DB) + strlen(pkgid) + 1;
	char* pkg_dir = malloc(pkg_dir_len + 1);
	snprintf(pkg_dir, pkg_dir_len + 1, "%s/%s", PKG_DB, pkgid);
	if (access(pkg_dir, F_OK) != 0) {
        fprintf(stderr, "Package '%s' not found in database\n", pkgid);
		free(pkg_dir);
		return false;
    }

	// construct package description script path and ensure it exists
	size_t script_path_len = pkg_dir_len + strlen(pkgid) + 4;
	info->script_path = malloc(script_path_len + 1);
	snprintf(info->script_path, script_path_len + 1, "%s/%s.sh", pkg_dir, pkgid);
	free(pkg_dir);
	if (access(info->script_path, F_OK) != 0) {
        fprintf(stderr, "Package '%s' broken, doesn't have description script\n", pkgid);
		free(info->script_path);
		return false;
    }

	// run getpkginfo script that outputs package attributes
	size_t cmd_len = strlen(PKG_INFO_CMD) + script_path_len + 3;
	char* cmd = malloc(cmd_len + 1);
	snprintf(cmd, cmd_len + 1, "%s '%s'", PKG_INFO_CMD, info->script_path);
	FILE* getinfo_fp = popen(cmd, "r");
	if (getinfo_fp == NULL) {
        perror("failed to popen getpkginfo");
		exit(1); // fatal error
    }

	// go through each NULL delimited section of the output
	size_t n = 0;
	char* line = NULL;
	ssize_t read;
	while ((read = getdelim(&line, &n, '\0', getinfo_fp)) != -1) {
		// read in property based on first attribute type character
		char  atype  = line[0];
		char* avalue = line+1;
		switch (atype) {
			case 'i':
				// id
				info->id = strdup(avalue);
				break;
			case 'n':
				// name
				info->name = strdup(avalue);
				break;
			case 'd':
				// description
				info->desc = strdup(avalue);
				break;
		}
    }
	free(line);

	// close the getpkginfo process
	if (pclose(getinfo_fp) != 0) {
        perror("failed to pclose getpkginfo");
		exit(1); // fatal error
	}

	return true;
}