// demo.c -- Demonstration of the cooperative task switching library
//
// Shows priority scheduling, round-robin, pausing/resuming, and
// dynamic priority changes.

#include <stdio.h>
#include "taskswitch.h"

// Forward declarations
static void pauseTarget(void *arg);
static void worker(void *arg);


static void pauseTarget(void *arg) {
    (void)arg;
    for (int32_t i = 0; i < 10; i++) {
        printf("  [pauser] iteration %d\n", (int)i);
        tsYield();
    }
    printf("  [pauser] finished\n");
}


static void worker(void *arg) {
    const char *name = (const char *)arg;
    int32_t     pri  = tsGetPriority(tsCurrentId());

    for (int32_t i = 0; i < 5; i++) {
        printf("  [%s] step %d (priority %d)\n", name, (int)i, (int)pri);
        tsYield();
    }
    printf("  [%s] finished\n", name);
}


int main(void) {
    printf("=== Cooperative Task Switching Demo ===\n\n");

    if (tsInit(8) != TS_OK) {
        printf("ERROR: failed to initialize task system\n");
        return 1;
    }

    int32_t tHigh   = tsCreate("high",   worker,      "high",   0, TS_PRIORITY_HIGH);
    int32_t tNorm   = tsCreate("normal", worker,      "normal", 0, TS_PRIORITY_NORMAL);
    int32_t tLow    = tsCreate("low",    worker,      "low",    0, TS_PRIORITY_LOW);
    int32_t tPauser = tsCreate("pauser", pauseTarget, NULL,     0, TS_PRIORITY_NORMAL);

    if (tHigh < 0 || tNorm < 0 || tLow < 0 || tPauser < 0) {
        printf("ERROR: failed to create tasks\n");
        tsShutdown();
        return 1;
    }

    printf("Created: high=%d normal=%d low=%d pauser=%d\n\n", (int)tHigh, (int)tNorm, (int)tLow, (int)tPauser);

    // Phase 1: all tasks run, but high-priority tasks get more turns per round.
    // Low (priority 0) gets 1 turn, normal (5) gets 6, high (10) gets 11.
    printf("--- Phase 1: Priority scheduling ---\n");
    for (int32_t i = 0; i < 6; i++) {
        printf("[main] yield %d\n", (int)i);
        tsYield();
    }

    // Phase 2: pause the pauser task so it stops being scheduled
    printf("\n--- Phase 2: Pause 'pauser' ---\n");
    tsPause((uint32_t)tPauser);
    printf("[main] pauser state: %d (expect %d=paused)\n", tsGetState((uint32_t)tPauser), TaskStatePaused);
    for (int32_t i = 0; i < 4; i++) {
        printf("[main] yield %d (pauser is paused)\n", (int)i);
        tsYield();
    }

    // Phase 3: resume pauser
    printf("\n--- Phase 3: Resume 'pauser' ---\n");
    tsResume((uint32_t)tPauser);
    for (int32_t i = 0; i < 4; i++) {
        printf("[main] yield %d\n", (int)i);
        tsYield();
    }

    // Phase 4: boost low to the highest priority so it gets more turns
    printf("\n--- Phase 4: Boost 'low' to highest ---\n");
    tsSetPriority((uint32_t)tLow, TS_PRIORITY_HIGH + 5);
    for (int32_t i = 0; i < 6; i++) {
        printf("[main] yield %d\n", (int)i);
        tsYield();
    }

    printf("\nActive tasks: %u\n", (unsigned)tsActiveCount());
    printf("=== Demo complete ===\n");

    tsShutdown();
    return 0;
}