/**
 * @file test_stress.c
 * @brief Stress tests for system
 */

#include "unity.h"
#include "kernel.h"
#include "task.h"
#include "semaphore.h"
#include "queue.h"
#include <string.h>

/* Stress test constants */
#define STRESS_TEST_DURATION    5000   /* 5 seconds */
#define MAX_STRESS_TASKS        20
#define STRESS_QUEUE_SIZE       100

/* Stress test variables */
static TaskHandle_t stress_tasks[MAX_STRESS_TASKS];
static Semaphore_t stress_semaphores[MAX_STRESS_TASKS];
static Queue_t stress_queue;
static volatile uint32_t task_counts[MAX_STRESS_TASKS];
static volatile uint32_t total_executions = 0;
static volatile bool stress_test_passed = true;

/* Stress task function */
static void stress_task(void* params) {
    uint32_t task_id = (uint32_t)params;

    while (1) {
        /* Increment counters */
        task_counts[task_id]++;
        total_executions++;

        /* Semaphore operations */
        semaphore_take(&stress_semaphores[task_id], 10);
        semaphore_give(&stress_semaphores[task_id]);

        /* Queue operations */
        uint32_t data = task_id;
        queue_send(&stress_queue, &data, 0);
        queue_receive(&stress_queue, &data, 0);

        /* Random delay */
        kernel_delay((task_id % 5) + 1);
    }
}

/* Setup */
void setUp(void) {
    kernel_init();
    total_executions = 0;
    stress_test_passed = true;

    /* Initialize stress test resources */
    queue_create(&stress_queue, malloc(STRESS_QUEUE_SIZE * sizeof(uint32_t)),
                 sizeof(uint32_t), STRESS_QUEUE_SIZE);

    for (int i = 0; i < MAX_STRESS_TASKS; i++) {
        semaphore_create(&stress_semaphores[i], SEMAPHORE_BINARY, 1, 1);
        task_counts[i] = 0;
    }
}

/* Teardown */
void tearDown(void) {
    kernel_stop();
}

/* ============================================================================
 * Test Cases
 * ============================================================================ */

/**
 * @brief Test with maximum tasks
 */
void test_max_tasks_stress(void) {
    /* Create maximum number of tasks */
    for (int i = 0; i < MAX_STRESS_TASKS; i++) {
        TaskConfig_t config = {
            .name = "stress_task",
            .function = stress_task,
            .parameters = (void*)(uint32_t)i,
            .stack_size = 1024,
            .priority = i % MAX_PRIORITY_LEVELS,
            .period_ticks = 0
        };

        stress_tasks[i] = task_create(&config);
        TEST_ASSERT_NOT_NULL(stress_tasks[i]);
    }

    /* Run stress test */
    kernel_start();
    kernel_delay(STRESS_TEST_DURATION);

    /* Verify all tasks executed */
    for (int i = 0; i < MAX_STRESS_TASKS; i++) {
        TEST_ASSERT_GREATER_THAN(0, task_counts[i]);
    }

    TEST_ASSERT_GREATER_THAN(1000, total_executions);
}

/**
 * @brief Test context switching stress
 */
void test_context_switch_stress(void) {
    /* Create tasks that cause frequent context switches */
    for (int i = 0; i < 5; i++) {
        TaskConfig_t config = {
            .name = "ctx_switch",
            .function = stress_task,
            .parameters = (void*)(uint32_t)i,
            .stack_size = 512,
            .priority = i,
            .period_ticks = 0
        };

        stress_tasks[i] = task_create(&config);
    }

    kernel_start();
    kernel_delay(1000);

    SchedulerStatistics_t stats;
    scheduler_get_statistics(&stats);

    TEST_ASSERT_GREATER_THAN(100, stats.context_switches);
}

/**
 * @brief Test memory stress
 */
void test_memory_stress(void) {
    /* Allocate and free memory repeatedly */
    void* pointers[100];

    for (int iteration = 0; iteration < 100; iteration++) {
        for (int i = 0; i < 100; i++) {
            pointers[i] = malloc(128);
            TEST_ASSERT_NOT_NULL(pointers[i]);
        }

        for (int i = 0; i < 100; i++) {
            free(pointers[i]);
        }
    }

    TEST_ASSERT_TRUE(true);
}

/**
 * @brief Test interrupt stress
 */
void test_interrupt_stress(void) {
    /* Enable maximum interrupts */
    kernel_start();

    /* Generate interrupt load */
    for (int i = 0; i < 1000; i++) {
        /* Trigger software interrupts */
        __asm volatile("SVC #0");
    }

    kernel_delay(100);

    TEST_ASSERT_TRUE(stress_test_passed);
}

/* ============================================================================
 * Test Runner
 * ============================================================================ */
int main(void) {
    UNITY_BEGIN();

    RUN_TEST(test_max_tasks_stress);
    RUN_TEST(test_context_switch_stress);
    RUN_TEST(test_memory_stress);
    RUN_TEST(test_interrupt_stress);

    return UNITY_END();
}