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#include "ServerEvents.h"
#include "CurlResult.h"

void ServerEvents_init(struct ServerEvents* this) {
    Buffer_init(&this->buffer);
    this->callbacks = List_create();
    this->handle = NULL;
}

void ServerEvents_destroyMembers(struct ServerEvents* this) {
    Buffer_destroyMembers(&this->buffer);
    if (this->handle) {
        curl_easy_cleanup(this->handle);
    }
    List_destroyWithContent(this->callbacks, free);
}

void ServerEvents_connect(struct ServerEvents* this, const char* baseUrl, CURLM* multiHandle) {
    char url[512];
    sprintf(url, "%s/api/events/all", baseUrl);

    CURL* handle = curl_easy_init();
    curl_easy_setopt(handle, CURLOPT_URL, url);
    /* curl_easy_setopt(handle, CURLOPT_TIMEOUT, 0); */
    /* curl_easy_setopt(handle, CURLOPT_NOSIGNAL, 1); */
    curl_easy_setopt(handle, CURLOPT_WRITEDATA, this);
    curl_easy_setopt(handle, CURLOPT_WRITEFUNCTION, ServerEvents_write);
    if (this->handle) {
        curl_easy_cleanup(handle);
    }

    this->handle = handle;
    curl_multi_add_handle(multiHandle, handle);
}

void ServerEvents_addCallback(struct ServerEvents* this,
                              void(*fn)(const char*,const char*,void*), void* userdata) {
    size_t size = sizeof(struct ServerEventCallback);
    struct ServerEventCallback* cb = malloc(size);
    cb->fn = fn;
    cb->userdata = userdata;
    List_pushBack(this->callbacks, cb);
}

/* event: name */
/* data: asdjflokjpa */
/* data: kljasdklafkjsdfl continues n times */
/*  */
size_t ServerEvents_write(void* buffer, size_t charSize, size_t bufferSize, void* userdata) {
    if (!userdata) {
        return 0;
    }
    struct ServerEvents* this = userdata;
    size_t result = Buffer_append(&this->buffer, buffer, (bufferSize*charSize));

    if (/* result > 0 && */ /* TODO correct error check */
        this->buffer.bufferUsed > 2 &&
        ((this->buffer.buffer[this->buffer.bufferUsed-1] == '\n' &&
          this->buffer.buffer[this->buffer.bufferUsed-2] == '\n') ||
         (this->buffer.buffer[this->buffer.bufferUsed-2] == '\n' &&
          this->buffer.buffer[this->buffer.bufferUsed-3] == '\n'))) {

        ServerEvents_parseMessage(this);

        Buffer_destroyMembers(&this->buffer);
        Buffer_init(&this->buffer);
    }
    return result;
}

void ServerEvents_parseMessage(struct ServerEvents* this) {
    char* message = this->buffer.buffer;
    char* event = NULL;
    if (0 == strncmp(message, "event: ", sizeof("event: ")-1)) {
        const char* eventNameStart = message + sizeof("event: ")-1;
        while(*message != '\0' && *message != '\n') {
            ++message;
        }
        event = copy_string(eventNameStart, (message-eventNameStart));

    }
    ++message;

    struct Buffer dataBuffer;
    Buffer_init(&dataBuffer);
    while ((message < this->buffer.buffer + this->buffer.bufferUsed) &&
           0 == strncmp(message, "data: ", sizeof("data: ")-1)) {
        const char* dataStart = message + sizeof("data: ")-1;
        while(*message != '\0' && *message != '\n') {
            ++message;
        }
        Buffer_append(&dataBuffer, dataStart, (message-dataStart)+1);
        ++message;
    }

    for (ListNode* it = this->callbacks->first; it; it=it->next) {
        struct ServerEventCallback* cb = it->data;
        Buffer_append(&dataBuffer, "\0", 1);
        cb->fn(event, dataBuffer.buffer, cb->userdata);
    }

    safe_free(event);
    Buffer_destroyMembers(&dataBuffer);
}