From df515b8cadee5b98feef748e7d5093465ee6f17b Mon Sep 17 00:00:00 2001
From: Yves Biener <yves.biener@gmx.de>
Date: Sat, 30 Nov 2024 14:45:57 +0100
Subject: [PATCH] mod: remove dependency to c std library and replace with
 ztime dependency for a pure zig implementation

---
 build.zig     | 21 +++++++++------------
 build.zig.zon |  6 ++++++
 src/zlog.zig  |  9 ++-------
 3 files changed, 17 insertions(+), 19 deletions(-)

diff --git a/build.zig b/build.zig
index 629fd6e..40477d7 100644
--- a/build.zig
+++ b/build.zig
@@ -27,14 +27,19 @@ pub fn build(b: *std.Build) void {
     // set a preferred release mode, allowing the user to decide how to optimize.
     const optimize = b.standardOptimizeOption(.{});
 
+    const ztime_dependency = b.dependency("ztime", .{
+        .target = target,
+        .optimize = optimize,
+    });
+
     const zlog_module = b.addModule("zlog", .{
         // In this case the main source file is merely a path, however, in more
         // complicated build scripts, this could be a generated file.
         .root_source_file = b.path("src/zlog.zig"),
         .target = target,
         .optimize = optimize,
-        .link_libc = include_timestamp, // uses c std library <time.h>
     });
+    zlog_module.addImport("ztime", ztime_dependency.module("ztime"));
     zlog_module.addImport("build_options", options_module);
 
     const exe = b.addExecutable(.{
@@ -43,6 +48,7 @@ pub fn build(b: *std.Build) void {
         .target = target,
         .optimize = optimize,
     });
+    exe.root_module.addImport("ztime", ztime_dependency.module("ztime"));
     exe.root_module.addImport("zlog", zlog_module);
 
     // This declares intent for the executable to be installed into the
@@ -50,17 +56,6 @@ pub fn build(b: *std.Build) void {
     // step when running `zig build`).
     b.installArtifact(exe);
 
-    const exe_check = b.addExecutable(.{
-        .name = "check",
-        .root_source_file = b.path("src/main.zig"),
-        .target = target,
-        .optimize = optimize,
-    });
-    exe_check.root_module.addImport("zlog", zlog_module);
-
-    const check = b.step("check", "Check if project compiles");
-    check.dependOn(&exe_check.step);
-
     // This *creates* a Run step in the build graph, to be executed when another
     // step is evaluated that depends on it. The next line below will establish
     // such a dependency.
@@ -91,6 +86,8 @@ pub fn build(b: *std.Build) void {
         .target = target,
         .optimize = optimize,
     });
+    lib_unit_tests.root_module.addImport("ztime", ztime_dependency.module("ztime"));
+    lib_unit_tests.root_module.addImport("build_options", options_module);
 
     const run_lib_unit_tests = b.addRunArtifact(lib_unit_tests);
 
diff --git a/build.zig.zon b/build.zig.zon
index 47fe730..d873fbd 100644
--- a/build.zig.zon
+++ b/build.zig.zon
@@ -3,6 +3,12 @@
     // version name should match the zig version except for the last number,
     // which stands for the version inside a given zig version
     .version = "0.13.0",
+    .dependencies = .{
+        .ztime = .{
+            .url = "git+https://gitea.yves-biener.de/yves-biener/ztime#c0f370c1c4673bb5f1fc1a1266e9819bafec0082",
+            .hash = "1220f094aa3a4e38ed4140da594e9eae3a3d66e7ba5eb3ea3f6fb7ed561d6981c6be",
+        },
+    },
     .minimum_zig_version = "0.13.0",
     .paths = .{
         "build.zig",
diff --git a/src/zlog.zig b/src/zlog.zig
index 03cae86..443eba4 100644
--- a/src/zlog.zig
+++ b/src/zlog.zig
@@ -1,5 +1,5 @@
 const build_options = @import("build_options");
-const c_time = if (build_options.timestamp) @cImport(@cInclude("time.h")) else null;
+const ztime = if (build_options.timestamp) @import("ztime") else null;
 const std = @import("std");
 
 pub const std_options: std.Options = .{
@@ -55,12 +55,7 @@ fn log_writing(writer: anytype, comptime fmt: []const u8, args: anytype) void {
 }
 
 fn log_timestamp(writer: anytype) void {
-    const curtime = c_time.time(null);
-    const tm = c_time.localtime(&curtime);
-
-    var buffer: [16]u8 = undefined;
-    _ = c_time.strftime(@ptrCast(&buffer), 32, "%F %R", tm);
-    writer.print("[{s}] ", .{buffer}) catch return;
+    writer.print("[{any}] ", .{ztime.DateTime.now()}) catch return;
 }
 
 pub fn pretty_format(object: anytype, comptime fmt: []const u8, options: std.fmt.FormatOptions, writer: anytype) !void {