#include "date_format.h"
#include <gtest/gtest.h>
#include <cstdlib>
#include <ctime>

using namespace radiantwave::datetime;

class DateFormatTest : public ::testing::Test {
protected:
    static void SetUpTestSuite() {
        setenv("TZ", "UTC", 1);
        tzset();
    }
};

TEST_F(DateFormatTest, DefaultFormatConstant) {
    EXPECT_STREQ(DEFAULT_DATE_FORMAT, "%m/%d/%Y");
}

TEST_F(DateFormatTest, FormatsKnownTimestamp) {
    std::tm tm = {};
    tm.tm_year = 2026 - 1900;
    tm.tm_mon = 8 - 1;
    tm.tm_mday = 4;
    tm.tm_hour = 14;
    tm.tm_min = 23;
    tm.tm_sec = 45;
    tm.tm_isdst = -1;
    time_t t = mktime(&tm);

    ASSERT_NE(t, static_cast<time_t>(-1));
    EXPECT_EQ(formatDate(t, "%m/%d/%Y"), "08/04/2026");
    EXPECT_EQ(formatDate(t, "%d/%m/%Y"), "04/08/2026");
    EXPECT_EQ(formatDate(t, "%Y-%m-%d"), "2026-08-04");
    EXPECT_EQ(formatDate(t, "%m.%d.%Y"), "08.04.2026");
    EXPECT_EQ(formatDate(t, "%d.%m.%Y"), "04.08.2026");
    EXPECT_EQ(formatDate(t, "%B %d, %Y"), "August 04, 2026");
    EXPECT_EQ(formatDate(t, "%d %B %Y"), "04 August 2026");
}

TEST_F(DateFormatTest, FormatsTime) {
    std::tm tm = {};
    tm.tm_year = 2026 - 1900;
    tm.tm_mon = 8 - 1;
    tm.tm_mday = 4;
    tm.tm_hour = 14;
    tm.tm_min = 23;
    tm.tm_sec = 45;
    tm.tm_isdst = -1;
    time_t t = mktime(&tm);

    ASSERT_NE(t, static_cast<time_t>(-1));
    EXPECT_EQ(formatTime(t), "14:23:45");
}

TEST_F(DateFormatTest, OptionsIncludeDefault) {
    auto options = getDateFormatOptions();
    ASSERT_FALSE(options.empty());
    EXPECT_EQ(options[0].pattern, std::string(DEFAULT_DATE_FORMAT));
    EXPECT_EQ(options[0].name, "Month/Day/Year");
}

TEST_F(DateFormatTest, Converts24HourTo12HourLabels) {
    EXPECT_EQ(formatHm12h("00:00"), "12:00 AM");
    EXPECT_EQ(formatHm12h("00:05"), "12:05 AM");
    EXPECT_EQ(formatHm12h("11:59"), "11:59 AM");
    EXPECT_EQ(formatHm12h("12:00"), "12:00 PM");
    EXPECT_EQ(formatHm12h("12:30"), "12:30 PM");
    EXPECT_EQ(formatHm12h("13:00"), "1:00 PM");
    EXPECT_EQ(formatHm12h("23:59"), "11:59 PM");
}

TEST_F(DateFormatTest, LeavesMalformedInputUnchanged) {
    EXPECT_EQ(formatHm12h(""), "");
    EXPECT_EQ(formatHm12h("7:05"), "7:05");
    EXPECT_EQ(formatHm12h("24:00"), "24:00");
    EXPECT_EQ(formatHm12h("12:60"), "12:60");
    EXPECT_EQ(formatHm12h("ab:cd"), "ab:cd");
}

TEST_F(DateFormatTest, Formats12HourClock) {
    std::tm morning = {};
    morning.tm_year = 2026 - 1900;
    morning.tm_mon = 8 - 1;
    morning.tm_mday = 4;
    morning.tm_hour = 7;
    morning.tm_min = 5;
    morning.tm_sec = 0;
    morning.tm_isdst = -1;
    time_t tMorning = mktime(&morning);
    ASSERT_NE(tMorning, static_cast<time_t>(-1));
    EXPECT_EQ(formatTime12h(tMorning), "7:05 AM");

    std::tm midnight = {};
    midnight.tm_year = 2026 - 1900;
    midnight.tm_mon = 8 - 1;
    midnight.tm_mday = 4;
    midnight.tm_hour = 0;
    midnight.tm_min = 0;
    midnight.tm_sec = 0;
    midnight.tm_isdst = -1;
    time_t tMidnight = mktime(&midnight);
    ASSERT_NE(tMidnight, static_cast<time_t>(-1));
    EXPECT_EQ(formatTime12h(tMidnight), "12:00 AM");

    std::tm evening = {};
    evening.tm_year = 2026 - 1900;
    evening.tm_mon = 8 - 1;
    evening.tm_mday = 4;
    evening.tm_hour = 19;
    evening.tm_min = 5;
    evening.tm_sec = 0;
    evening.tm_isdst = -1;
    time_t tEvening = mktime(&evening);
    ASSERT_NE(tEvening, static_cast<time_t>(-1));
    EXPECT_EQ(formatTime12h(tEvening), "7:05 PM");
}