1 files changed, 27 insertions, 10 deletions

diff --git a/snag/src/download_db.c b/snag/src/download_db.c
index c1e2e1b..c355566 100644
--- a/snag/src/download_db.c
+++ b/snag/src/download_db.c
@@ -6,6 +6,7 @@
 #include <openssl/evp.h>
 #include <openssl/sha.h>
 #include <string.h>
+#include <unistd.h>
 #include <errno.h>
 
 // note: fixed location of download database for now
@@ -29,10 +30,22 @@ static size_t download_write_callback(char* ptr, size_t size, size_t nmemb, void
 	return written;
 }
 
-bool download_package(package_info_t* pkg) {
+bool package_get_download(package_info_t* pkg, package_download_t* download) {
+    memset(download, 0, sizeof(*download));
 
+	// construct path of download
+	char* download_path = vastrcat(download_db_path, "/", pkg->attrs.id, "-", pkg->attrs.version, ".tar.gz");
+
+	// return download if it already exists in database
+    if (access(download_path, F_OK) == 0) {
+		download->download_path = download_path;
+		return true;
+    } else {
+		print("Downloading %s\n", pkg->attrs.source_url);
+	}
+
+	// initialize curl if it isn't already
 	if (curl == NULL) {
-		// initialize curl if it isn't already
 		CURLcode result = curl_global_init(CURL_GLOBAL_ALL);
 		if (result != CURLE_OK) die("failed to initialize curl: %s", curl_easy_strerror(result));
 		curl = curl_easy_init(); // note(jqj): for now we reuse one easy curl object
@@ -43,8 +56,8 @@ bool download_package(package_info_t* pkg) {
 		/* curl_global_cleanup(); */
 	}
 
+	// initialize libcrypto context if it isn't already
 	if (mdctx == NULL) {
-		// initialize libcrypto context if it isn't already
 		mdctx = EVP_MD_CTX_new();
 		md = EVP_sha256();
 
@@ -59,7 +72,6 @@ bool download_package(package_info_t* pkg) {
 	// note(jqj): extension is fixed to tar gz until the switch out download
 	//            attrs for the swenu api download command which will specify
 	//            more information
-	char* download_path = vastrcat(download_db_path, "/", pkg->attrs.id, "-", pkg->attrs.version, ".tar.gz");
 	FILE* download_file = fopen(download_path, "wb");
 	if (download_file == NULL) die("failed open download file for writing (%s): %s", download_path, strerror(errno));
 
@@ -73,7 +85,7 @@ bool download_package(package_info_t* pkg) {
     if(result != CURLE_OK) {
 		// todo(jqj): handle better, maybe try again
 		print("failed to download package with curl: %s", curl_easy_strerror(result));
-		return false;
+		goto fail;
 	}
 
 	// get sha256 hash
@@ -88,20 +100,25 @@ bool download_package(package_info_t* pkg) {
     }
 	hash_hex[SHA256_DIGEST_LENGTH * 2] = '\0';
 
+	// todo(jqj): collapse codepath and delete download if it doesn't match checksum
+
 	// confirm that hash matches checksum
 	if (pkg->attrs.source_checksum != NULL) {
 		if (strcmp(pkg->attrs.source_checksum, hash_hex) == 0) {
-			print("checksum verified for %s: %s\n", pkg->attrs.id, hash_hex);
+			print("checksum verified for download: %s\n", hash_hex);
+			download->download_path = download_path;
 			return true;
 		} else {
-			print("FAIL: bad checksum for %s: %s\n", pkg->attrs.id, hash_hex);
-			return false;
+			print("FAIL: bad checksum for download: %s\n", hash_hex);
+			goto fail;
 		}
 	} else {
 		// todo(jqj): not sure if we will allow packages without hashes yet
 		print("WARNING: could not verify checksum for %s download because none was provided\n", pkg->attrs.id);
-		return true;
+		goto fail;
 	}
 
-	return true;
+ fail:
+	free(download_path);
+	return false;
 }