/*
* Copyright (C) 2021 Duowan Inc. All rights reserved.
*
* Licensed under the Apache License, Version 2.0 (the "License"); 
* you may not use this file except in compliance with the License. 
* You may obtain a copy of the License at
*
*    http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, 
* software distributed under the License is distributed on an "AS IS" BASIS, 
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 
* See the License for the specific language governing permissions and 
* limitations under the License.
*/


#ifndef __X_PACK_BSON_ENCODER_H
#define __X_PACK_BSON_ENCODER_H

#include "libbson-1.0/bson.h"

#include "xpack/util.h"
#include "xpack/xencoder.h"

namespace xpack {

class BsonEncoder:public XEncoder<BsonEncoder>, private noncopyable {
    struct Node {
        const char *key;
        Node    *parent;
        bson_t data;
        
        Node(const char *_key = NULL, Node *_parent=NULL):key(_key), parent(_parent) {
            if (NULL == parent) {
                bson_init(&data);
            }
        }
        ~Node() {
            if (NULL == parent) {
                bson_destroy(&data);
            }
        }
    };
public:
    friend class XEncoder<BsonEncoder>;
    using xdoc_type::encode;

    BsonEncoder(const char*key = NULL, Node*parent = NULL) {
        cur = new Node(key, parent);
        nodes.push_back(cur);
    }

    ~BsonEncoder() {
        std::list<Node*>::iterator it;
        for (it = nodes.begin(); it!=nodes.end(); ++it) {
            delete *it;
        }
    }

    inline const char *Type() const {
        return "bson";
    }
    inline const char *IndexKey(size_t index) {
        if (index > indexStr.size()+1) {
            std::string s = Util::itoa(index);
            errCase.push_back(s);
            return errCase.back().c_str();
        }
        if (index >= indexStr.size()) {
            std::string s = Util::itoa(index);
            indexStr.push_back(s);
        }
        return indexStr[index].c_str();
    }

    // return bson binary data
    std::string String() const {
        return std::string((const char*)bson_get_data(&cur->data), cur->data.len);
    }
    // return json format string
    std::string Json() const {
        size_t len;
        char *jstr = bson_as_json(&cur->data, &len);
        std::string ret(jstr);
        bson_free(jstr);

        return ret;
    }

public:
    void ArrayBegin(const char *key, const Extend *ext) {
        (void)ext;
        if (key != NULL) {
            Node *tmp = new Node(key, cur);
            nodes.push_back(tmp);

            bson_append_array_begin(&cur->data, key, strlen(key), &tmp->data);
            cur = tmp;
        }
    }
    void ArrayEnd(const char *key, const Extend *ext) {
        (void)ext;
        if (NULL != key) {
            bson_append_array_end(&cur->parent->data, &cur->data);
            cur = cur->parent; // do not pop and delete
        }
    }
    void ObjectBegin(const char *key, const Extend *ext) {
        (void)ext;
        if (key != NULL) {
            Node *tmp = new Node(key, cur);
            nodes.push_back(tmp);

            bson_append_document_begin(&cur->data, key, strlen(key), &tmp->data);
            cur = tmp;
        }
    }
    void ObjectEnd(const char *key, const Extend *ext) {
        (void)ext;
        if (NULL != key) { // in case of inherit, object key is NULL
            bson_append_document_end(&cur->parent->data, &cur->data);
            cur = cur->parent; // do not pop and delete
        }
    }
    bool writeNull(const char*key, const Extend *ext) {
        if (Extend::OmitEmpty(ext)) {
            return false;
        }
        bson_append_null(&cur->data, key, strlen(key));
        return true;
    }
    bool encode(const char*key, const char* val, const Extend *ext) {
        if (NULL==val && Extend::OmitEmpty(ext)){
            return false;
        }
        if (NULL != val) {
            bson_append_utf8(&cur->data, key, strlen(key), val, strlen(val));
        } else {
            bson_append_utf8(&cur->data, key, strlen(key), "", 0);
        }

        return true;
    }

    bool encode(const char*key, const std::string& val, const Extend *ext) {
        if (val.empty() && Extend::OmitEmpty(ext)){
            return false;
        }

        bson_append_utf8(&cur->data, key, strlen(key), (const char*)val.data(), val.length());
        return true;
    }

    bool encode(const char*key, const bool &val, const Extend *ext) {
        (void)ext;
        bson_append_bool(&cur->data, key, strlen(key), val);
        return true;
    }


    #define X_PACK_BSON_ENCODE_NUMBER(vtype, ftype, ctype)          \
    bool encode(const char*key, const vtype&val, const Extend*ext) {\
        if (val==0 && Extend::OmitEmpty(ext)){                      \
            return false;                                           \
        } else {                                                    \
            bson_append_##ftype(&cur->data, key, strlen(key), (vtype)val);\
            return true;                                            \
        }                                                           \
    }

    X_PACK_BSON_ENCODE_NUMBER(char, int32, int32_t)
    X_PACK_BSON_ENCODE_NUMBER(signed char, int32, int32_t)
    X_PACK_BSON_ENCODE_NUMBER(unsigned char, int32, int32_t)
    X_PACK_BSON_ENCODE_NUMBER(short, int32, int32_t)
    X_PACK_BSON_ENCODE_NUMBER(unsigned short, int32, int32_t)
    X_PACK_BSON_ENCODE_NUMBER(int, int32, int32_t)
    X_PACK_BSON_ENCODE_NUMBER(unsigned int, int32, int32_t)

    X_PACK_BSON_ENCODE_NUMBER(long, int64, int64_t)
    X_PACK_BSON_ENCODE_NUMBER(unsigned long, int64, int64_t)
    X_PACK_BSON_ENCODE_NUMBER(long long, int64, int64_t)
    X_PACK_BSON_ENCODE_NUMBER(unsigned long long, int64, int64_t)

    X_PACK_BSON_ENCODE_NUMBER(float, double, double)
    X_PACK_BSON_ENCODE_NUMBER(double, double, double)
    X_PACK_BSON_ENCODE_NUMBER(long double, double, double)

private:
    std::vector<std::string> indexStr;
    std::list<std::string> errCase;
    std::list<Node*> nodes;
    Node *cur;
};

}

#endif