//! Build-time version info exposed via the `build_info` module.
//!
//! `version_string` is `git describe --tags --always --dirty` output (or the
//! `.version` field from `build.zig.zon` if git is unavailable at build time).
//! `build_timestamp` is the committer timestamp of HEAD (Unix epoch
//! seconds), or 0 when git is unavailable. Together they identify the
//! binary precisely.
//!
//! The timestamp is deliberately per-commit rather than wall-clock: it
//! keeps the build-options module cache-stable, so repeated `zig build`
//! invocations don't relink the exe just because the second ticked over.
//!
//! Consumers (the `zfin version` command, snapshot metadata writers, bug
//! reports) should route through this module rather than importing
//! `build_info` directly, so the interface stays stable if we reshape the
//! build options later.

const std = @import("std");
const build_info = @import("build_info");

/// Version string, e.g. "v0.3.1", "v0.3.1-4-g1a2b3c4", "v0.3.1-dirty",
/// "1a2b3c4" (no tags yet), or a fallback from build.zig.zon.
pub const version_string: []const u8 = build_info.version;

/// Unix epoch seconds — committer timestamp of HEAD at build time, or 0
/// when git is unavailable. Rendered as ISO date by the `zfin version
/// --verbose` command; 0 renders as 1970-01-01 (clearly-fake sentinel).
pub const build_timestamp: i64 = build_info.build_timestamp;

/// True when `version_string` ends in `-dirty`, indicating the build was
/// produced from a worktree with uncommitted changes.
pub fn isDirty() bool {
    return std.mem.endsWith(u8, version_string, "-dirty");
}

test "version_string is non-empty" {
    try std.testing.expect(version_string.len > 0);
}

test "build_timestamp is either zero (no-git fallback) or a plausible commit time" {
    // Two acceptable shapes:
    //   0               → git unavailable or `git log -1 %ct` failed
    //   > 1_577_836_800 → real committer timestamp (Jan 1 2020 onward)
    // Anything in between would indicate a broken build-info wiring.
    try std.testing.expect(build_timestamp == 0 or build_timestamp > 1_577_836_800);
}
