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

struct DataNode {
    uint32_t dataLength;     
    char *data;          
    struct DataNode *next;   
};

DataNode* splitData(char *buffer, uint32_t bufferSize) {
    DataNode *head = NULL;
    DataNode *tail = NULL;
    uint32_t offset = 0;

    while (offset < bufferSize) {
        if (offset + 4 > bufferSize) {
            break; 
        }

        uint32_t dataLength = *(uint32_t *)(buffer + offset);
        offset += 4;

        if (offset + dataLength > bufferSize) {
            break;
        }

        DataNode *newNode = (DataNode *)malloc(sizeof(DataNode));
        if (newNode == NULL) {
            perror("Memory allocation failed");
            freeDataNodes(head); // 释放已分配的节点内存
            return NULL;
        }

        newNode->data = (char *)malloc(dataLength);
        if (newNode->data == NULL) {
            free(newNode);
            perror("Memory allocation failed");
            freeDataNodes(head); // 释放已分配的节点内存
            return NULL;
        }
        memcpy(newNode->data, buffer + offset, dataLength);
        newNode->dataLength = dataLength;
        newNode->next = NULL;

        if (head == NULL) {
            head = newNode;
        } else {
            tail->next = newNode;
        }
        tail = newNode;

        offset += dataLength;
    }
    return head;
}

void freeDataNodes(DataNode *head) {
    while (head != NULL) {
        DataNode *next = head->next;
        free(head->data);
        free(head);
        head = next;
    }
}

void printDataList(DataNode *head) {
    int index = 0;
    DataNode *current = head;
    while (current != NULL) {
        printf("Data %d: Length = %u\n", index, current->dataLength);
        index++;
        current = current->next;
    }
}

int getDataNodeCount(DataNode *head) {
    int count = 0;
    DataNode *current = head;
    while (current != NULL) {
        count++;
        current = current->next;
    }
    return count;
}

const char* getDataNodeByIndex(DataNode *head, int index) {
    int count = 1;
    DataNode *current = head;
    while (current != NULL) {
        if (count == index) {
            return current->data;
        }
        count++;
        current = current->next;
    }
    return NULL; // 如果索引超出范围，返回NULL
}