Add libtags for extracting info from files

3 files changed, 94 insertions, 4 deletions

diff --git a/src/database/CMakeLists.txt b/src/database/CMakeLists.txt
index 0bc6f6b9..47f8fe31 100644
--- a/src/database/CMakeLists.txt
+++ b/src/database/CMakeLists.txt
@@ -1,7 +1,7 @@
 idf_component_register(
   SRCS "env_esp.cpp" "database.cpp" "tag_processor.cpp" "db_task.cpp"
   INCLUDE_DIRS "include"
-  REQUIRES "result" "span" "esp_psram" "fatfs")
+  REQUIRES "result" "span" "esp_psram" "fatfs" "libtags")
 
 target_compile_options(${COMPONENT_LIB} PRIVATE ${EXTRA_WARNINGS})
 
diff --git a/src/database/include/tag_processor.hpp b/src/database/include/tag_processor.hpp
index fb2201db..eda88225 100644
--- a/src/database/include/tag_processor.hpp
+++ b/src/database/include/tag_processor.hpp
@@ -6,6 +6,8 @@ namespace database {
 
 struct FileInfo {
   bool is_playable;
+  std::string artist;
+  std::string album;
   std::string title;
 };
 
diff --git a/src/database/tag_processor.cpp b/src/database/tag_processor.cpp
index 16dbf160..5752d61b 100644
--- a/src/database/tag_processor.cpp
+++ b/src/database/tag_processor.cpp
@@ -1,14 +1,102 @@
 #include "tag_processor.hpp"
 
+#include <ff.h>
+#include <tags.h>
+#include <esp_log.h>
+
 namespace database {
 
+namespace libtags {
+
+struct Aux {
+  FIL file;
+  FILINFO info;
+  std::string artist;
+  std::string album;
+  std::string title;
+};
+
+static int read(Tagctx *ctx, void *buf, int cnt) {
+	Aux *aux = reinterpret_cast<Aux*>(ctx->aux);
+        UINT bytes_read;
+        if (f_read(&aux->file, buf, cnt, &bytes_read) != FR_OK) {
+          return -1;
+        }
+        return bytes_read;
+}
+
+static int seek(Tagctx *ctx, int offset, int whence) {
+	Aux *aux = reinterpret_cast<Aux*>(ctx->aux);
+        FRESULT res;
+        if (whence == 0) {
+          // Seek from the start of the file. This is f_lseek's behaviour.
+          res = f_lseek(&aux->file, offset);
+        } else if (whence == 1) {
+          // Seek from current offset.
+          res = f_lseek(&aux->file, aux->file.fptr + offset);
+        } else if (whence == 2) {
+          // Seek from the end of the file
+          res = f_lseek(&aux->file, aux->info.fsize + offset);
+        } else {
+          return -1;
+        }
+	return res;
+}
+
+static void
+tag(Tagctx *ctx, int t, const char *k, const char *v, int offset, int size, Tagread f) {
+  Aux *aux = reinterpret_cast<Aux*>(ctx->aux);
+  if (t == Ttitle) {
+    aux->title = v;
+  } else if (t == Tartist) {
+    aux->artist = v;
+  } else if (t == Talbum) {
+    aux->album = v;
+  }
+}
+
+static void
+toc(Tagctx *ctx, int ms, int offset) {}
+
+} // namespace libtags
+
+static const std::size_t kBufSize = 1024;
+static const char* kTag = "TAGS";
+
 auto GetInfo(const std::string& path, FileInfo* out) -> bool {
-  // TODO(jacqueline): bring in taglib for this
-  if (path.ends_with(".mp3")) {
+  libtags::Aux aux;
+  if (f_stat(path.c_str(), &aux.info) != FR_OK || f_open(&aux.file, path.c_str(), FA_READ) != FR_OK) {
+    ESP_LOGI(kTag, "failed to open file");
+    return false;
+  }
+  // Fine to have this on the stack; this is only called on the leveldb task.
+  char buf[kBufSize];
+  Tagctx ctx;
+    ctx.read = libtags::read;
+    ctx.seek = libtags::seek;
+    ctx.tag = libtags::tag;
+    ctx.toc = libtags::toc;
+    ctx.aux = &aux;
+    ctx.buf = buf;
+    ctx.bufsz = kBufSize;
+  int res = tagsget(&ctx);
+  f_close(&aux.file);
+
+  if (res != 0) {
+    ESP_LOGI(kTag, "failed to parse tags");
+    return false;
+  }
+
+  if (ctx.format == Fmp3) {
+    ESP_LOGI(kTag, "file is mp3");
+    ESP_LOGI(kTag, "artist: %s", aux.artist.c_str());
+    ESP_LOGI(kTag, "album: %s", aux.album.c_str());
+    ESP_LOGI(kTag, "title: %s", aux.title.c_str());
     out->is_playable = true;
-    out->title = path.substr(0, path.size() - 4);
+    out->title = aux.title;
     return true;
   }
+
   return false;
 }