Day 10: Add creating entries

Signed-off-by: Aaron Fischer <mail@aaron-fischer.net>

src/main.zig

@@ -3,6 +3,7 @@ const builtin = @import("builtin");
 const eql = @import("std").mem.eql;
 
 const stdout = std.io.getStdOut().writer();
+const stdin = std.io.getStdIn().reader();
 
 pub fn main() !void {
     // Read the first argument to determine the subcommand
@@ -27,7 +28,34 @@ pub fn main() !void {
 }
 
 fn createNewEntry() !void {
-    // TODO
+    // Open the file in append mode
+    const file = try std.fs.cwd().openFile("entries.log.gmi", .{ .mode = .read_write });
+    defer file.close();
+    try file.seekFromEnd(0);
+
+    //const date = try std.time.Time.nowUTC().format("yyyy-MM-dd HH:mm UTC");
+    const es = std.time.epoch.EpochSeconds{ .secs = @intCast(std.time.timestamp()) };
+    const ed = std.time.epoch.EpochDay{ .day = es.getEpochDay().day };
+    var buf2: [256]u8 = undefined;
+    const date = try std.fmt.bufPrint(&buf2, "## {d}-{d:0>2}-{d:0>2} {d:0>2}:{d:0>2} UTC\n", .{
+        ed.calculateYearDay().year,
+        std.time.epoch.YearAndDay.calculateMonthDay(ed.calculateYearDay()).month.numeric(),
+        std.time.epoch.YearAndDay.calculateMonthDay(ed.calculateYearDay()).day_index,
+        es.getDaySeconds().getHoursIntoDay(),
+        es.getDaySeconds().getMinutesIntoHour(),});
+
+    // Read the input content from STDIN and append it to the file
+    var buf: [1024]u8 = undefined;
+    while (try stdin.readUntilDelimiterOrEof(&buf, '\n')) |line| {
+        try file.writeAll("\n");
+        try file.writeAll(date);
+        try file.writeAll(line);
+        try file.writeAll("\n");
+    }
+
+    // Print some success message and the back link to STDOUT
+    try stdout.print("Entry added successfully\n", .{});
+    try stdout.print("=> / Back to the log entries", .{});
 }
 
 fn listEntries() !void {