//
// Created by shuxin ¡¡¡¡zheng on 2023/7/19.
//

#include "stdafx.h"
#include "redis_object.h"

namespace pkv {

redis_object::redis_object(redis_object* parent) {
    dbuf_   = new (1) acl::dbuf_pool();
    parent_ = parent ? parent : this;
}

const char* redis_object::get_cmd() const {
    if (me_ == nullptr) {
        return nullptr;
    }

    if (me_->get_type() == acl::REDIS_RESULT_STRING) {
        return me_->get(0);
    }

    if (objs_.empty() || me_->get_type() != acl::REDIS_RESULT_ARRAY) {
        return nullptr;
    }

    return objs_[0]->get_cmd();
}

const char* redis_object::get_str() const {
    if (me_->get_type() == acl::REDIS_RESULT_STRING) {
        return me_->get(0);
    }

    return nullptr;
}

struct status_machine {
    /* ״̬Âë */
    int status;

    /* ״̬»ú´¦Àíº¯Êý */
    const char* (redis_object::*func) (const char*, size_t&);
};

static struct status_machine status_tab[] = {
    { redis_s_begin,    &redis_object::parse_begin      },
    { redis_s_status,   &redis_object::parse_status     },
    { redis_s_error,    &redis_object::parse_error      },
    { redis_s_number,   &redis_object::parse_number     },
    { redis_s_strlen,   &redis_object::parse_strlen     },
    { redis_s_string,   &redis_object::parse_string     },
    { redis_s_strend,   &redis_object::parse_strend     },
    { redis_s_arlen,    &redis_object::parse_arlen      },
    { redis_s_array,    &redis_object::parse_array      },
};

const char* redis_object::update(const char *data, size_t& len) {
    if (failed() || finish())  {
        return data;
    }

    if (obj_) {
        return parse_object(data, len);
    }

    while (len > 0) {
        data  = (this->*(status_tab[status_].func))(data, len);
        if (status_ == redis_s_null || status_ == redis_s_finish) {
            break;
        }
    }

    return data;
}

const char* redis_object::parse_object(const char* data, size_t& len) {
    assert(cnt_ > 0);
    assert(obj_);

    data = obj_->update(data, len);
    if (obj_->failed()) {
        status_ = redis_s_null;
        return data;
    }

    if (!obj_->finish()) {
        return data;
    }

    objs_.emplace_back(obj_);

    if (objs_.size() == (size_t) cnt_) {
        obj_ = nullptr;
        cnt_ = 0;
        status_ = redis_s_finish;
    } else {
        obj_ = std::make_shared<redis_object>(this);
    }
    return data;
}

const char* redis_object::parse_begin(const char* data, size_t& len) {
    if (len == 0) {
        return data;
    }

    switch (*data) {
    case ':':	// INTEGER
        status_ = redis_s_number;
        break;
    case '+':	// STATUS
        status_ = redis_s_status;
        break;
    case '-':	// ERROR
        status_ = redis_s_error;
        break;
    case '$':	// STRING
        status_ = redis_s_strlen;
        break;
    case '*':	// ARRAY
        status_ = redis_s_arlen;
        break;
    default:	// INVALID
        status_ = redis_s_null;
        break;
    }

    len--;
    data++;
    return data;
}

const char* redis_object::parse_status(const char* data, size_t& len) {
    bool found = false;
    data = get_line(data, len, found);
    if (!found) {
        assert(len == 0);
        return data;
    }

    if (buf_.empty()) {
        status_ = redis_s_null;
        return data;
    }

    me_ = new(dbuf_) acl::redis_result(dbuf_);
    me_->set_type(acl::REDIS_RESULT_STATUS);
    me_->set_size(1);
    put_data(dbuf_, me_, buf_.c_str(), buf_.length());
    buf_.clear();

    status_ = redis_s_finish;
    return data;
}

const char* redis_object::parse_error(const char* data, size_t& len) {
    bool found = false;
    data = get_line(data, len, found);
    if (!found) {
        assert(len == 0);
        return data;
    }

    if (buf_.empty()) {
        status_ = redis_s_null;
        return data;
    }

    me_ = new(dbuf_) acl::redis_result(dbuf_);
    me_->set_type(acl::REDIS_RESULT_ERROR);
    me_->set_size(1);
    put_data(dbuf_, me_, buf_.c_str(), buf_.length());
    buf_.clear();

    status_ = redis_s_finish;
    return data;
}

const char* redis_object::parse_number(const char* data, size_t& len) {
    bool found = false;
    data = get_line(data, len, found);
    if (!found) {
        assert(len == 0);
        return data;
    }

    if (buf_.empty()) {
        status_ = redis_s_null;
        return data;
    }

    me_ = new(dbuf_) acl::redis_result(dbuf_);
    me_->set_type(acl::REDIS_RESULT_INTEGER);
    me_->set_size(1);
    put_data(dbuf_, me_, buf_.c_str(), buf_.length());
    buf_.clear();

    status_ = redis_s_finish;
    return data;
}

const char* redis_object::parse_strlen(const char* data, size_t& len) {
    bool found = false;
    cnt_ = 0;
    data = get_length(data, len, cnt_, found);
    if (status_ == redis_s_null || !found) {
        return data;
    }

    me_ = new(dbuf_) acl::redis_result(dbuf_);
    me_->set_type(acl::REDIS_RESULT_STRING);

    if (cnt_ <= 0) {
        status_ = redis_s_finish;
        return data;
    }

    me_->set_size((size_t) cnt_);
    buf_.clear();

    status_ = redis_s_string;
    return data;
}

const char* redis_object::parse_string(const char* data, size_t& len) {
    assert (me_ != nullptr);

    data = get_data(data, len, (size_t) cnt_);
    if (buf_.size() == (size_t) cnt_) {
        status_ = redis_s_strend;
        put_data(dbuf_, me_, buf_.c_str(), buf_.length());
        buf_.clear();
        cnt_ = 0;
    }

    return data;
}

const char* redis_object::parse_strend(const char* data, size_t& len) {
    assert (me_ != nullptr);

    bool found = false;
    data = get_line(data, len, found);

    // If the buf_ not empty, some data other '\r\n' got.
    if (!buf_.empty()) {
        status_ = redis_s_null;
        return data;
    }

    if (!found) {
        assert(len == 0);
        return data;
    }

    status_ = redis_s_finish;
    return data;
}

const char* redis_object::parse_arlen(const char* data, size_t& len) {
    bool found = false;
    cnt_ = 0;
    data = get_length(data, len, cnt_, found);
    if (status_ == redis_s_null || !found) {
        return data;
    }

    me_ = new(dbuf_) acl::redis_result(dbuf_);
    me_->set_type(acl::REDIS_RESULT_ARRAY);

    if (cnt_ <= 0) {
        status_ = redis_s_finish;
        return data;
    }

    me_->set_size((size_t) cnt_);

    buf_.clear();
    status_ = redis_s_array;
    obj_ = std::make_shared<redis_object>(this);
    return data;
}

const char* redis_object::parse_array(const char* data, size_t& len) {
    assert(me_ != nullptr);
    assert(obj_ != nullptr);

    return parse_object(data, len);
}

const char* redis_object::get_data(const char* data, size_t& len, size_t want) {
    size_t n = buf_.size();
    assert(n < want);

    want -= n;
    for (size_t i = 0; i < want && len > 0; i++) {
        buf_.push_back(*data++);
        len--;
    }
    return data;
}

const char* redis_object::get_length(const char* data, size_t& len,
      int& res, bool& found) {
    data = get_line(data, len, found);
    if (!found) {
        assert(len == 0);
        return data;
    }

    if (buf_.empty()) {
        status_ = redis_s_null;
        return data;
    }

    // buf_.push_back('\0');  // The c++11 promise the last char is null.
    char* endptr;
    res = (int) strtol(buf_.c_str(), &endptr, 10);
    buf_.clear();

    if (endptr == buf_.c_str() || *endptr != '\0') {
        status_ = redis_s_null;
        return data;
    }
    return data;
}

const char* redis_object::get_line(const char* data, size_t& len, bool& found) {
    while (len > 0) {
        switch (*data) {
        case '\r':
            data++;
            len--;
            break;
        case '\n':
            data++;
            len--;
            found = true;
            return data;
        default:
            buf_.push_back(*data++);
            len--;
            break;
        }
    }
    return data;
}

void redis_object::put_data(acl::dbuf_pool* dbuf, acl::redis_result* rr,
      const char* data, size_t len) {
    char* buf = (char*) dbuf->dbuf_alloc(len + 1);
    if (len > 0) {
        memcpy(buf, data, len);
    }

    buf[len] = 0;
    rr->put(buf, len);
}

bool redis_object::to_string(acl::string& out) const {
#define USE_UNIX_CRLF
#ifdef USE_UNIX_CRLF
#define CRLF    "\n"
#else
#define CRLF    "\r\n"
#endif

    if (!objs_.empty()) {
        out.format_append("*%zd%s", objs_.size(), CRLF);

        for (const auto& obj : objs_) {
            if (!obj->to_string(out)) {
                return false;
            }
        }
    }

    if (me_ == nullptr) {
        return false;
    }

    switch (me_->get_type()) {
    case acl::REDIS_RESULT_STATUS:
        out.format_append("+%s%s", me_->get_status(), CRLF);
        break;
    case acl::REDIS_RESULT_ERROR:
        out.format_append("-%s%s", me_->get_error(), CRLF);
        break;
    case acl::REDIS_RESULT_INTEGER:
        out.format_append(":%lld%s", me_->get_integer64(), CRLF);
        break;
    case acl::REDIS_RESULT_STRING:
        out.format_append("$%zd%s", me_->get_length(), CRLF);
        me_->argv_to_string(out, false);
        out += CRLF;
        break;
    //case acl::REDIS_RESULT_ARRAY:
    //    break;
    default:
        break;
    }
    return true;
}

redis_object& redis_object::set_status(const std::string& data,
      bool return_parent) {
    me_ = new(dbuf_) acl::redis_result(dbuf_);
    me_->set_type(acl::REDIS_RESULT_STATUS);
    me_->set_size(1);
    put_data(dbuf_, me_, data.c_str(), data.length());
    return return_parent ? *parent_ : *this;
}

redis_object& redis_object::set_error(const std::string& data,
      bool return_parent) {
    me_ = new(dbuf_) acl::redis_result(dbuf_);
    me_->set_type(acl::REDIS_RESULT_ERROR);
    me_->set_size(1);
    put_data(dbuf_, me_, data.c_str(), data.length());
    return return_parent ? *parent_ : *this;
}

redis_object& redis_object::set_number(int n, bool return_parent) {
    me_ = new(dbuf_) acl::redis_result(dbuf_);
    me_->set_type(acl::REDIS_RESULT_INTEGER);
    me_->set_size(1);

    std::string buf = std::to_string(n);
    put_data(dbuf_, me_, buf.c_str(), buf.length());
    return return_parent ? *parent_ : *this;
}

redis_object& redis_object::set_string(const std::string &data,
      bool return_parent) {
    me_ = new(dbuf_) acl::redis_result(dbuf_);
    me_->set_type(acl::REDIS_RESULT_STRING);
    me_->set_size(data.size());
    if (!data.empty()) {
        put_data(dbuf_, me_, data.c_str(), data.length());
    }
    return return_parent ? *parent_ : *this;
}

redis_object& redis_object::create_child() {
    auto obj = std::make_shared<redis_object>(this);
    objs_.emplace_back(obj);

    if (me_ == nullptr) {
        // The last one is NULL.
        me_ = new(dbuf_) acl::redis_result(dbuf_);
        me_->set_type(acl::REDIS_RESULT_ARRAY);
    }

    me_->set_size(objs_.size());
    return *obj;
}

} // namespace pkv