From 041167d26fdcce1203f99698ecd5a1709d6870ba Mon Sep 17 00:00:00 2001
From: Abdelrahman <said.abdelrahman89@gmail.com>
Date: Thu, 2 Nov 2023 00:12:03 +0000
Subject: [PATCH] Implement pack reading functions

---
 include/pak.h |  5 +++--
 src/pak.c     | 40 +++++++++++++++++++++++++++++++++++++++-
 2 files changed, 42 insertions(+), 3 deletions(-)

diff --git a/include/pak.h b/include/pak.h
index 28bac05..12e4cb5 100644
--- a/include/pak.h
+++ b/include/pak.h
@@ -6,7 +6,7 @@
 
 typedef struct {
   u64 size;
-  u8 *data;
+  u8 data[];
 } buf_t;
 
 typedef struct {
@@ -41,7 +41,8 @@ typedef struct asset_pack asset_pack_t;
 
 bool create_asset_pack(const char *dirpath, const char *output);
 asset_pack_t *load_asset_pack(const char *filepath);
-// buf_t read_file_from_pack(pak_read_t *pack, const char *filename);
+buf_t *read_file_from_pack(asset_pack_t *pack, const char *filename);
+void close_pack_file(buf_t **buf);
 void close_asset_pack(asset_pack_t **pack);
 
 #endif // !PAK_H
diff --git a/src/pak.c b/src/pak.c
index 9bcca28..d81ab62 100644
--- a/src/pak.c
+++ b/src/pak.c
@@ -176,7 +176,45 @@ asset_pack_t *load_asset_pack(const char *filepath) {
   return pack;
 }
 
-// buf_t read_file_from_pack(pak_read_t *pack, const char *filename) {}
+buf_t *read_file_from_pack(asset_pack_t *pack, const char *filename) {
+  toc_entry_t *entry = NULL;
+  buf_t *output = NULL;
+
+  for (u64 i = 0; i < pack->header.toc.count; ++i) {
+    entry = pack->toc_entries[i];
+
+    if (STRNEQ(filename, entry->name, entry->length)) {
+      fseek(pack->fp, pack->assets_offset + entry->offset, SEEK_SET);
+
+      u64 size = 0;
+      fread(&size, sizeof(u64), 1, pack->fp);
+
+      output = (buf_t *)malloc(sizeof(buf_t) + size);
+      if (!output) {
+        break;
+      }
+
+      output->size = size;
+
+      fread(&(output->data), size, 1, pack->fp);
+
+      break;
+    }
+  }
+
+  return output;
+}
+
+void close_pack_file(buf_t **buf) {
+  buf_t *b = *buf;
+
+  if (!b || b->size == 0) {
+    return;
+  }
+
+  free(*buf);
+  *buf = NULL;
+}
 
 void close_asset_pack(asset_pack_t **pack) {
   if (!(*pack)) {