/*
 * UniversalisOS ESP32 — 2-Task Demo
 *
 * Task A prints "A0\n" through "A9\n"
 * Task B prints "B0\n" through "B9\n"
 * Alternating via semaphore. Co-routine pattern.
 *
 * Build: make TARGET=esp32hw
 * Load:  U-Boot auto-boot (jumps to entry point)
 */

#include "uos_api.h"
#include "uos_hal.h"

/* ---- Task stacks (static allocation, Tier 0) ---- */
UOS_TASK_DEF(task_a, 1, 1024);
UOS_TASK_DEF(task_b, 1, 1024);

/* ---- Semaphore for alternating ---- */
UOS_SEM_DEF(sync_a);
UOS_SEM_DEF(sync_b);

/* ---- Shared counter ---- */
static volatile int s_counter = 0;

/* ---- Task A entry ---- */
static void task_a_entry(void *arg)
{
    (void)arg;
    while (s_counter < 10) {
        uos_sem_wait(&sync_a_sem, UOS_WAIT_FOREVER);

        uos_hal_uart_putc('A');
        uos_hal_uart_putc('0' + s_counter);
        uos_hal_uart_putc('\n');

        s_counter++;
        uos_sem_post(&sync_b_sem);
    }

    /* Task A done — signal B one last time and exit */
    uos_sem_post(&sync_b_sem);
    uos_task_delete(NULL);  /* delete self */
}

/* ---- Task B entry ---- */
static void task_b_entry(void *arg)
{
    (void)arg;
    while (s_counter < 10) {
        uos_sem_wait(&sync_b_sem, UOS_WAIT_FOREVER);

        if (s_counter >= 10) break;

        uos_hal_uart_putc('B');
        uos_hal_uart_putc('0' + s_counter);
        uos_hal_uart_putc('\n');

        uos_sem_post(&sync_a_sem);
    }

    uos_hal_uart_puts("DONE\n");
    /* Infinite idle — keep running */
    for (;;) {
        __asm__ volatile("waiti 0");
    }
}

/* ---- Main entry (called by startup) ---- */
int main(void)
{
    /* 1. Early hardware init */
    uos_hal_wdt_disable_all();
    uos_hal_uart_init(115200);

    uos_hal_uart_puts("UOS ESP32 2-Task Demo\n");

    /* 2. Initialize kernel */
    uos_init();

    /* 3. Create synchronization semaphores */
    uos_sem_init(&sync_a_sem, "sync_a", 1);  /* Task A starts first */
    uos_sem_init(&sync_b_sem, "sync_b", 0);

    /* 4. Create tasks */
    uos_task_create("task_a", 1, task_a_entry, NULL,
                    task_a_stack_mem, sizeof(task_a_stack_mem));
    uos_task_create("task_b", 1, task_b_entry, NULL,
                    task_b_stack_mem, sizeof(task_b_stack_mem));
    /* Suppress unused-variable warnings for static task structs */
    (void)&task_a_task; (void)&task_b_task;

    /* 5. Start scheduler — never returns */
    uos_hal_uart_puts("Starting scheduler...\n");
    uos_sched_start();

    /* NOTREACHED */
    for (;;) __asm__ volatile("waiti 0");
    return 0;
}