#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include "hx_ringbuffer.h"

int by_ringbuf_init(by_ringbuf_t *rb, int size) {
#ifdef BY_RINGBUF_STATIC_ALLOC
    // 使用预先分配的内存
    static uint8_t static_buffer[BY_RINGBUF_STATIC_BUFFER_SIZE]; 
    
    if (size > sizeof(static_buffer)) {
        return -1; // 预先分配的内存不足
    }
    rb->buffer = static_buffer;
#else
    // 使用 malloc 动态分配内存
    rb->buffer = (uint8_t *)malloc(size);
    if (rb->buffer == NULL) {
        return -1; // 分配内存失败
    }
#endif

    rb->size = size;
    rb->head = 0;
    rb->tail = 0;
    rb->is_full = false;
    return 0;
}

void by_ringbuf_free(by_ringbuf_t *rb) {
#ifndef BY_RINGBUF_STATIC_ALLOC
    // 只有使用 malloc 分配的内存才需要释放
    if (rb->buffer) {
        free(rb->buffer);
        rb->buffer = NULL;
    }
#endif

    rb->size = 0;
    rb->head = 0;
    rb->tail = 0;
    rb->is_full = false;
}

int by_ringbuf_append(by_ringbuf_t *rb, const uint8_t *data, int len) {
    if (len > by_ringbuf_available_space(rb)) {
        return -1; // 缓冲区空间不足
    }

    for (int i = 0; i < len; i++) {
        rb->buffer[rb->head] = data[i];
        rb->head = (rb->head + 1) % rb->size;
        if (rb->head == rb->tail) {
            rb->is_full = true;
        }
    }

    return len;
}

int by_ringbuf_pop(by_ringbuf_t *rb, uint8_t *data, int len) {
    if (len > by_ringbuf_available_data(rb)) {
        return -1; // 数据不足
    }

    for (int i = 0; i < len; i++) {
        data[i] = rb->buffer[rb->tail];
        rb->tail = (rb->tail + 1) % rb->size;
        rb->is_full = false;
    }

    return len;
}

int by_ringbuf_find(by_ringbuf_t *rb, const uint8_t *pattern, int pattern_len) {
    int available_data = by_ringbuf_available_data(rb);
    if (pattern_len > available_data) {
        return -1; // 数据不足，无法查找
    }

    for (int i = 0; i <= available_data - pattern_len; i++) {
        int match = 1;
        for (int j = 0; j < pattern_len; j++) {
            int index = (rb->tail + i + j) % rb->size;
            if (rb->buffer[index] != pattern[j]) {
                match = 0;
                break;
            }
        }
        if (match) {
            return i; // 返回匹配的起始位置
        }
    }

    return -1; // 未找到匹配
}

int by_ringbuf_available_data(by_ringbuf_t *rb) {
    if (rb->is_full) {
        return rb->size;
    }
    return (rb->head - rb->tail + rb->size) % rb->size;
}

int by_ringbuf_available_space(by_ringbuf_t *rb) {
    return rb->size - by_ringbuf_available_data(rb);
}

// 调试函数：打印环形缓冲区中的数据及其序号
void by_ringbuf_debug_print(by_ringbuf_t *rb) {
    int available_data = by_ringbuf_available_data(rb);
    if (available_data == 0) {
        printf("Ring buffer is empty.\n");
        return;
    }

    printf("Ring buffer content (size: %d, available data: %d):\n", rb->size, available_data);
    for (int i = 0; i < available_data; i++) {
        int index = (rb->tail + i) % rb->size;
        printf("[%04d] 0x%02X\n", i, rb->buffer[index]);
    }
}