/* A4 之二：`rail_set_mv()` —— 三个验收主项（固件开发计划 §5 A4 那一行）：
     ① 4020 mV 被拒（SR-13）
     ② **写更大的码值，输出更低**（反向关系）
     ③ 3900 mV ↔ Vd 0.548 V
   都在下面打了 ⭐。 */
#include "dac63204.h"
#include "phonerail.h"
#include "rail.h"
#include "sim_hal.h"
#include "unity.h"

void setUp(void) { sim_hal_reset(); }
void tearDown(void) {}

/* 两片假 DAC 都挂上，并预置 DEVICE-ID 与 COMMON-CONFIG 的复位值。 */
static void mount_both(void)
{
    for (int i = 0; i < DAC63204_COUNT; i++) {
        uint8_t a = dac63204_all_addr[i];
        sim_i2c_add(a, 2);
        sim_i2c_set_reg(a, DAC63204_REG_GENERAL_STATUS, (uint16_t)(DAC63204_DEVICE_ID << 2));
        sim_i2c_set_reg(a, DAC63204_REG_COMMON_CONFIG, 0x0FFF);
    }
    TEST_ASSERT_EQUAL_INT(HAL_OK, hal_i2c_init(NULL));
}

/* 直接从假器件的寄存器里把某一路的码抠出来（绕开被测代码自己的读路径）。 */
static uint16_t raw_code(int rail)
{
    uint16_t reg = sim_i2c_get_reg(dac63204_rail_addr(rail),
                                   DAC63204_REG_DATA(dac63204_rail_ch(rail)));
    return DAC63204_REG_TO_CODE(reg);
}

/* ---- ① 越界即拒（SR-13） --------------------------------------------------- */

/* ⭐ 验收主项一：4020 mV 必须被拒，而且**一个字节都不许发出去**。
   这是第四道限制，前三道在硬件里（设计文档 §4.1）—— 它的作用是让操作者早点
   知道自己写错了，不是靠它保安全。 */
static void test_4020_mv_is_rejected(void)
{
    mount_both();
    TEST_ASSERT_EQUAL_INT(HAL_OK, rail_volt_init());

    for (int rail = 1; rail <= PHONERAIL_RAIL_COUNT; rail++) {
        uint16_t before = raw_code(rail);
        TEST_ASSERT_EQUAL_INT_MESSAGE(HAL_ERR_ARG, rail_set_mv(rail, 4020), "4020 mV 必须被拒");
        TEST_ASSERT_EQUAL_UINT16_MESSAGE(before, raw_code(rail), "被拒的请求不许改到 DAC");
    }
    TEST_ASSERT_FALSE(rail_mv_in_range(4011));
    TEST_ASSERT_TRUE(rail_mv_in_range(RAIL_MV_MAX));
}

/* 下限同样拒：DAC 满码也到不了 3523 mV，悄悄夹到 3524 就成了「设了但没设到」。 */
static void test_below_range_is_rejected(void)
{
    mount_both();
    TEST_ASSERT_EQUAL_INT(HAL_OK, rail_volt_init());
    TEST_ASSERT_EQUAL_INT(HAL_ERR_ARG, rail_set_mv(1, RAIL_MV_MIN - 1));
    TEST_ASSERT_EQUAL_INT(HAL_ERR_ARG, rail_set_mv(1, 0));
    TEST_ASSERT_FALSE(rail_mv_in_range(3523));
    TEST_ASSERT_TRUE(rail_mv_in_range(RAIL_MV_MIN));
}

static void test_rail_index_is_one_based(void)
{
    mount_both();
    TEST_ASSERT_EQUAL_INT(HAL_ERR_ARG, rail_set_mv(0, RAIL_MV_SAFE));
    TEST_ASSERT_EQUAL_INT(HAL_ERR_ARG, rail_set_mv(6, RAIL_MV_SAFE));
    int mv = 0;
    TEST_ASSERT_EQUAL_INT(HAL_ERR_ARG, rail_get_mv(0, &mv));
    TEST_ASSERT_EQUAL_INT(HAL_ERR_ARG, rail_get_mv(1, NULL));
}

/* ---- ② 反向关系 ---------------------------------------------------------- */

/* ⭐ 验收主项二：**码越大，输出越低。**
   写反了不报错 —— 「调高电压」的命令把手机调到 3.52 V，手机照样开机，
   要跑一阵子才在负载尖峰下掉电。所以这里既查换算，也查真写进 DAC 的那个数。 */
static void test_higher_code_means_lower_voltage(void)
{
    /* 换算层：单调**递减**，端点钉死。 */
    TEST_ASSERT_EQUAL_UINT16(0, rail_mv_to_code(RAIL_MV_MAX));
    TEST_ASSERT_TRUE(rail_mv_to_code(RAIL_MV_MIN) > rail_mv_to_code(RAIL_MV_MAX));
    TEST_ASSERT_TRUE(rail_mv_to_code(3600) > rail_mv_to_code(4000));

    uint16_t prev = rail_mv_to_code(RAIL_MV_MIN);
    for (int mv = RAIL_MV_MIN + 1; mv <= RAIL_MV_MAX; mv++) {
        uint16_t code = rail_mv_to_code(mv);
        TEST_ASSERT_TRUE_MESSAGE(code <= prev, "mv 变大，码必须变小或持平");
        prev = code;
    }

    /* 总线层：同一路先设高再设低，DAC 里的数必须变大。 */
    mount_both();
    TEST_ASSERT_EQUAL_INT(HAL_OK, rail_volt_init());
    TEST_ASSERT_EQUAL_INT(HAL_OK, rail_set_mv(1, 4000));
    uint16_t at_4000 = raw_code(1);
    TEST_ASSERT_EQUAL_INT(HAL_OK, rail_set_mv(1, 3600));
    uint16_t at_3600 = raw_code(1);
    TEST_ASSERT_TRUE_MESSAGE(at_3600 > at_4000, "3.60 V 的码必须比 4.00 V 的大");
}

/* ---- ③ 3900 mV ↔ Vd 0.548 V --------------------------------------------- */

/* ⭐ 验收主项三：NVM 出厂默认那一点（设计文档 §4.3 / §10.5 的表）。 */
static void test_3900_mv_is_vd_548_mv(void)
{
    uint16_t code = rail_mv_to_code(3900);
    TEST_ASSERT_EQUAL_UINT16(926, code);
    /* Vd = 926 / 4096 × 2.424 V = 548.0 mV */
    TEST_ASSERT_INT32_WITHIN_MESSAGE(500, 548000, rail_code_to_vd_uv(code),
                                     "3900 mV 对应的 Vd 必须是 0.548 V");
    TEST_ASSERT_EQUAL_INT(3900, rail_code_to_mv(code));
}

/* 设计文档 §4.3 那三个角点，一个不落。 */
static void test_transfer_curve_endpoints(void)
{
    TEST_ASSERT_EQUAL_INT(RAIL_MV_MAX, rail_code_to_mv(0));      /* Vd 0 V   -> 4.010 V */
    TEST_ASSERT_EQUAL_INT(3900, rail_code_to_mv(926));           /* Vd 0.548 -> 3.900 V */
    TEST_ASSERT_EQUAL_INT(3524, rail_code_to_mv(DAC63204_CODE_MAX)); /* 满码 -> 3.524 V */

    /* 上下限都必须落在 12 位码里 —— 越界说明 RAIL_MV_MIN/MAX 和电阻值对不上了。 */
    TEST_ASSERT_TRUE(rail_mv_to_code(RAIL_MV_MIN) <= DAC63204_CODE_MAX);
    TEST_ASSERT_TRUE(rail_mv_to_code(RAIL_MV_MAX) <= DAC63204_CODE_MAX);
}

/* 全量程往返：设进去再读回来，误差不超过 1 mV（一个码在输出端 0.119 mV）。 */
static void test_set_get_round_trip(void)
{
    mount_both();
    TEST_ASSERT_EQUAL_INT(HAL_OK, rail_volt_init());
    for (int rail = 1; rail <= PHONERAIL_RAIL_COUNT; rail++) {
        for (int mv = RAIL_MV_MIN; mv <= RAIL_MV_MAX; mv += 7) {
            int back = 0;
            TEST_ASSERT_EQUAL_INT(HAL_OK, rail_set_mv(rail, mv));
            TEST_ASSERT_EQUAL_INT(HAL_OK, rail_get_mv(rail, &back));
            TEST_ASSERT_INT_WITHIN(1, mv, back);
        }
    }
}

/* ---- 五路互不串扰 --------------------------------------------------------- */

/* 改一路不许动到别的四路。CH1 与 CH2 在同一片（U6）上，是最容易串的一对。 */
static void test_setting_one_rail_leaves_the_others_alone(void)
{
    mount_both();
    TEST_ASSERT_EQUAL_INT(HAL_OK, rail_volt_init());

    uint16_t before[PHONERAIL_RAIL_COUNT + 1];
    for (int r = 1; r <= PHONERAIL_RAIL_COUNT; r++) {
        before[r] = raw_code(r);
    }
    TEST_ASSERT_EQUAL_INT(HAL_OK, rail_set_mv(1, 3600));
    for (int r = 2; r <= PHONERAIL_RAIL_COUNT; r++) {
        TEST_ASSERT_EQUAL_UINT16_MESSAGE(before[r], raw_code(r), "只该动 CH1");
    }
    TEST_ASSERT_TRUE(raw_code(1) != before[1]);
}

/* 五路各写一个不同的值，逐路读回来必须各是各的 —— 映射表串了这条就红。 */
static void test_each_rail_keeps_its_own_value(void)
{
    static const int want[PHONERAIL_RAIL_COUNT] = { 3600, 3700, 3800, 3900, 4000 };
    mount_both();
    TEST_ASSERT_EQUAL_INT(HAL_OK, rail_volt_init());
    for (int r = 1; r <= PHONERAIL_RAIL_COUNT; r++) {
        TEST_ASSERT_EQUAL_INT(HAL_OK, rail_set_mv(r, want[r - 1]));
    }
    for (int r = 1; r <= PHONERAIL_RAIL_COUNT; r++) {
        int back = 0;
        TEST_ASSERT_EQUAL_INT(HAL_OK, rail_get_mv(r, &back));
        TEST_ASSERT_INT_WITHIN(1, want[r - 1], back);
    }
}

/* ---- 初始化 -------------------------------------------------------------- */

/* 上电即安全值：init 完五路都应该在 3.90 V 上，不依赖后续有人来设。 */
static void test_init_leaves_every_rail_at_the_safe_value(void)
{
    mount_both();
    TEST_ASSERT_EQUAL_INT(HAL_OK, rail_volt_init());
    for (int r = 1; r <= PHONERAIL_RAIL_COUNT; r++) {
        int mv = 0;
        TEST_ASSERT_EQUAL_INT(HAL_OK, rail_get_mv(r, &mv));
        TEST_ASSERT_EQUAL_INT_MESSAGE(RAIL_MV_SAFE, mv, "上电安全值必须是 3900 mV");
    }
}

/* 少一片 DAC：init 必须如实失败（降级留给 A15，这里不许悄悄当成功）。 */
static void test_init_fails_when_a_chip_is_missing(void)
{
    sim_i2c_add(DAC63204_ADDR_U6, 2);
    sim_i2c_set_reg(DAC63204_ADDR_U6, DAC63204_REG_GENERAL_STATUS,
                    (uint16_t)(DAC63204_DEVICE_ID << 2));
    TEST_ASSERT_EQUAL_INT(HAL_OK, hal_i2c_init(NULL));
    TEST_ASSERT_EQUAL_INT(HAL_ERR_NAK, rail_volt_init()); /* U7 没挂 */
}

static void test_set_propagates_bus_errors(void)
{
    mount_both();
    TEST_ASSERT_EQUAL_INT(HAL_OK, rail_volt_init());
    sim_i2c_set_present(dac63204_rail_addr(3), false);
    TEST_ASSERT_EQUAL_INT(HAL_ERR_NAK, rail_set_mv(3, 3800));
    int mv = 0;
    TEST_ASSERT_EQUAL_INT(HAL_ERR_NAK, rail_get_mv(3, &mv));
}

int main(void)
{
    UNITY_BEGIN();
    RUN_TEST(test_4020_mv_is_rejected);
    RUN_TEST(test_below_range_is_rejected);
    RUN_TEST(test_rail_index_is_one_based);
    RUN_TEST(test_higher_code_means_lower_voltage);
    RUN_TEST(test_3900_mv_is_vd_548_mv);
    RUN_TEST(test_transfer_curve_endpoints);
    RUN_TEST(test_set_get_round_trip);
    RUN_TEST(test_setting_one_rail_leaves_the_others_alone);
    RUN_TEST(test_each_rail_keeps_its_own_value);
    RUN_TEST(test_init_leaves_every_rail_at_the_safe_value);
    RUN_TEST(test_init_fails_when_a_chip_is_missing);
    RUN_TEST(test_set_propagates_bus_errors);
    return UNITY_END();
}