allow images to upload and sort if according to their datetime

1 files changed, 54 insertions, 0 deletions

diff --git a/src/storage/image-manager/exif.zig b/src/storage/image-manager/exif.zig
new file mode 100644
index 0000000..02199cf
--- /dev/null
+++ b/src/storage/image-manager/exif.zig
@@ -0,0 +1,54 @@
+const std = @import("std");
+const exif = @cImport(@cInclude("libexif/exif-data.h"));
+const cstd = @cImport(@cInclude("time.h"));
+
+const tags = [_]c_uint {
+    exif.EXIF_TAG_DATE_TIME,
+    exif.EXIF_TAG_DATE_TIME_ORIGINAL,
+    exif.EXIF_TAG_DATE_TIME_DIGITIZED,
+};
+
+pub fn get_date_time(path: [*:0]const u8) ?i64 {
+    const exif_data = exif.exif_data_new_from_file(path);
+    defer exif.exif_data_unref(exif_data);
+
+    if (exif_data == null) {
+        return null;
+    }
+
+    var entry: ?[*c]exif.struct__ExifEntry = null;
+    for (0..exif.EXIF_IFD_COUNT) |index| {
+        for (tags) |tag| {
+            entry = exif.exif_content_get_entry((exif_data.*).ifd[index], tag);
+
+            if (entry) |_| { break; }
+        }
+
+        if (entry) |_| { break; }
+    }
+
+    if (entry == null) {
+        return null;
+    }
+
+    const c_data = (entry.?.*).data;
+
+    return parse_date(c_data);
+}
+
+extern fn strptime(
+   s: [*c]const u8,
+   format: [*c]const u8,
+    tm: *cstd.tm,
+) ?*const u8;
+
+extern fn timegm(tm: *cstd.tm) i64;
+
+fn parse_date(date: [*:0]const u8) ?i64 {
+    var tm: cstd.tm = std.mem.zeroes(cstd.tm);
+    if (strptime(date, "%Y:%m:%d %H:%M:%S", &tm)) |_| {
+        return timegm(&tm);
+    }
+
+    return null;
+}