package client

/*
#include <stdlib.h>
#include <td/telegram/td_json_client.h>
#include <td/telegram/td_log.h>
*/
import "C"

import (
    "encoding/json"
    "errors"
    "fmt"
    "strconv"
    "time"
    "unsafe"
)

type JsonClient struct {
    jsonClient unsafe.Pointer
}

func NewJsonClient() *JsonClient {
    return &JsonClient{
        jsonClient: C.td_json_client_create(),
    }
}

// Sends request to the TDLib client. May be called from any thread.
func (jsonClient *JsonClient) Send(req Request) {
    data, _ := json.Marshal(req)

    query := C.CString(string(data))
    defer C.free(unsafe.Pointer(query))

    C.td_json_client_send(jsonClient.jsonClient, query)
}

// Receives incoming updates and request responses from the TDLib client. May be called from any thread, but
// shouldn't be called simultaneously from two different threads.
// Returned pointer will be deallocated by TDLib during next call to td_json_client_receive or td_json_client_execute
// in the same thread, so it can't be used after that.
func (jsonClient *JsonClient) Receive(timeout time.Duration) (*Response, error) {
    result := C.td_json_client_receive(jsonClient.jsonClient, C.double(float64(timeout)/float64(time.Second)))
    if result == nil {
        return nil, errors.New("update receiving timeout")
    }

    data := []byte(C.GoString(result))

    var resp Response

    err := json.Unmarshal(data, &resp)
    if err != nil {
        return nil, err
    }

    resp.Data = data

    return &resp, nil
}

// Synchronously executes TDLib request. May be called from any thread.
// Only a few requests can be executed synchronously.
// Returned pointer will be deallocated by TDLib during next call to td_json_client_receive or td_json_client_execute
// in the same thread, so it can't be used after that.
func (jsonClient *JsonClient) Execute(req Request) (*Response, error) {
    data, _ := json.Marshal(req)

    query := C.CString(string(data))
    defer C.free(unsafe.Pointer(query))

    result := C.td_json_client_execute(jsonClient.jsonClient, query)
    if result == nil {
        return nil, errors.New("request can't be parsed")
    }

    data = []byte(C.GoString(result))

    var resp Response

    err := json.Unmarshal(data, &resp)
    if err != nil {
        return nil, err
    }

    resp.Data = data

    return &resp, nil
}

// Destroys the TDLib client instance. After this is called the client instance shouldn't be used anymore.
func (jsonClient *JsonClient) DestroyInstance() {
    C.td_json_client_destroy(jsonClient.jsonClient)
}

// Sets the path to the file where the internal TDLib log will be written.
// By default TDLib writes logs to stderr or an OS specific log.
// Use this method to write the log to a file instead.
func SetLogFilePath(filePath string) {
    query := C.CString(filePath)
    defer C.free(unsafe.Pointer(query))

    C.td_set_log_file_path(query)
}

// Sets maximum size of the file to where the internal TDLib log is written before the file will be auto-rotated.
// Unused if log is not written to a file. Defaults to 10 MB.
func SetLogMaxFileSize(maxFileSize int64) {
    C.td_set_log_max_file_size(C.longlong(maxFileSize))
}

// Sets the verbosity level of the internal logging of TDLib.
// By default the TDLib uses a log verbosity level of 5
func SetLogVerbosityLevel(newVerbosityLevel int) {
    C.td_set_log_verbosity_level(C.int(newVerbosityLevel))
}

type meta struct {
    Type  string `json:"@type"`
    Extra string `json:"@extra"`
}

type Request struct {
    meta
    Data map[string]interface{}
}

func (req Request) MarshalJSON() ([]byte, error) {
    req.Data["@type"] = req.Type
    req.Data["@extra"] = req.Extra

    return json.Marshal(req.Data)
}

type Response struct {
    meta
    Data json.RawMessage
}

type ResponseError struct {
    Err *Error
}

func (responseError ResponseError) Error() string {
    return fmt.Sprintf("%d %s", responseError.Err.Code, responseError.Err.Message)
}

func buildResponseError(data json.RawMessage) error {
    respErr, err := UnmarshalError(data)
    if err != nil {
        return err
    }

    return ResponseError{
        Err: respErr,
    }
}

// JsonInt64 alias for int64, in order to deal with json big number problem
type JsonInt64 int64

// MarshalJSON marshals to json
func (jsonInt64 *JsonInt64) MarshalJSON() ([]byte, error) {
    return []byte(strconv.FormatInt(int64(*jsonInt64), 10)), nil
}

// UnmarshalJSON unmarshals from json
func (jsonInt64 *JsonInt64) UnmarshalJSON(data []byte) error {
    jsonBigInt, err := strconv.ParseInt(string(data[1:len(data)-1]), 10, 64)
    if err != nil {
        return err
    }

    *jsonInt64 = JsonInt64(jsonBigInt)

    return nil
}

type Type interface {
    GetType() string
    GetClass() string
}