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const std = @import("std");
const Allocator = std.mem.Allocator;
const print = std.debug.print;
const types = @import("./lib/types.zig");
const CommandStatus = types.CommandStatus;
const OutputCapture = types.OutputCapture;
const InputSource = types.InputSource;
fn isLeapYear(year: u32) bool {
return (year % 4 == 0 and year % 100 != 0) or (year % 400 == 0);
}
pub const Date = struct {
pub fn eval(date: Date, allocator: Allocator, output_capture: ?*OutputCapture, input_source: ?*InputSource) !CommandStatus {
_ = date;
_ = input_source;
const timestamp = std.time.timestamp();
const epoch_seconds = @as(u64, @intCast(timestamp));
const epoch_day = @divFloor(epoch_seconds, std.time.s_per_day);
// Calculate days since Unix epoch (1970-01-01)
// Unix epoch is 719163 days since year 1 AD
const days_since_year_1 = epoch_day + 719163;
// Simple algorithm to convert days to year/month/day
var year: u32 = 1;
var remaining_days = days_since_year_1;
// Find the year
while (true) {
const days_in_year: u64 = if (isLeapYear(year)) 366 else 365;
if (remaining_days < days_in_year) break;
remaining_days -= days_in_year;
year += 1;
}
// Days in each month (non-leap year)
const days_in_month = [_]u32{ 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 };
var month: u32 = 1;
for (days_in_month, 1..) |days, m| {
var month_days = days;
// Adjust February for leap years
if (m == 2 and isLeapYear(year)) {
month_days = 29;
}
if (remaining_days < month_days) {
month = @intCast(m);
break;
}
remaining_days -= month_days;
}
const day = remaining_days + 1; // Days are 1-indexed
const output = try std.fmt.allocPrint(allocator, "Current date is {d:0>2}/{d:0>2}/{d}\n", .{ month, day, year });
defer allocator.free(output);
if (output_capture) |capture| {
try capture.write(output);
} else {
print("{s}", .{output});
}
return CommandStatus{ .Code = 0 };
}
};
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