/*
 * Copyright (c) 2020 Alex <alex@webz.asia>
 *
 *  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.
 *
 *   @author Alex <alex@webz.asia>
 *   @copyright Copyright (c) 2020 Alex <alex@webz.asia>
 *   @since 29.12.2020
 *
 */

package dtoLib

import (
	"errors"
	"fmt"
	"net/http"
	"net/url"

	"github.com/go-convert/fields"
)

type PaginationContainer struct {
	Pagination Pagination `json:"pagination"`
}

type Pagination struct {
	Page    int `json:"page"`
	PerPage int `json:"per_page"`
	Total   int `json:"total"`
}

type ApiResponse struct {
	Code    int32       `json:"code"`
	Type    string      `json:"type"`
	Message string      `json:"message"`
	Data    interface{} `json:"data"`
	*PaginationContainer
}

type ApiErrorResponse struct {
	Code    int32       `json:"code"`
	Type    string      `json:"type"`
	Message string      `json:"message"`
	Errors  []error     `json:"errors"`
	Data    interface{} `json:"data"`
}

type SearchParams url.Values

// AllApiResponses returns full map of map ApiResponse structure
func AllApiResponses() map[string]map[string]ApiResponse {
	return responseMap
}

// AddNewApiResponse adds new api response by name, returns error if already exists
func AddNewApiResponse(name string, response map[string]ApiResponse) error {
	if _, ok := responseMap[name]; ok {
		return errors.New("this name already exists")
	}
	responseMap[name] = response

	return nil
}

// AllApiErrorResponses returns full map of map ApiErrorResponse structure
func AllApiErrorResponses() map[string]map[string]ApiErrorResponse {
	return errorResponseMap
}

// AddNewApiErrorResponse adds new error api response by name, returns error if already exists
func AddNewApiErrorResponse(name string, response map[string]ApiErrorResponse) error {
	if _, ok := errorResponseMap[name]; ok {
		return errors.New("this name already exists")
	}
	errorResponseMap[name] = response

	return nil
}

// NotCreated returns http response code and error response object
func NotCreated(name string, errors []error) (int, ApiErrorResponse) {
	response, ok := errorResponseMap[name][StatusNotCreated]
	if ok {
		response.Errors = errors
		if len(errors) == 1 {
			response.Data = errors[0].Error()
		}
	} else {
		// fallback to other response, have to support it by default
		return FallbackToFailedError(name, errors)
	}

	return http.StatusNotAcceptable, response
}

// Created returns http response code and regular response object
func Created(name string, data interface{}) (int, ApiResponse) {
	response, ok := responseMap[name][StatusCreated]
	if ok {
		response.Data = data
	} else {
		// fallback to other response, have to support it by default
		return FallbackToFailed(name)
	}

	return http.StatusCreated, response
}

// NotUpdated returns http response code and error response object
func NotUpdated(name string, errors []error) (int, ApiErrorResponse) {
	response, ok := errorResponseMap[name][StatusNotUpdated]
	if ok {
		response.Errors = errors
		if len(errors) == 1 {
			response.Data = errors[0].Error()
		}
	} else {
		// fallback to other response, have to support it by default
		return FallbackToFailedError(name, errors)
	}

	return http.StatusNotAcceptable, response
}

// Updated returns http response code and regular response object
func Updated(name string, data interface{}) (int, ApiResponse) {
	response, ok := responseMap[name][StatusUpdated]
	if ok {
		response.Data = data
	} else {
		// fallback to other response, have to support it by default
		return FallbackToFailed(name)
	}

	return http.StatusAccepted, response
}

// NotDeleted returns http response code and error response object
func NotDeleted(name string, errors []error) (int, ApiErrorResponse) {
	response, ok := errorResponseMap[name][StatusNotDeleted]
	if ok {
		response.Errors = errors
		if len(errors) == 1 {
			response.Data = errors[0].Error()
		}
	} else {
		// fallback to other response, have to support it by default
		return FallbackToFailedError(name, errors)
	}

	return http.StatusNotFound, response
}

// Deleted returns http response code and regular response object
func Deleted(name string, data interface{}) (int, ApiResponse) {
	response, ok := responseMap[name][StatusDeleted]
	if ok {
		response.Data = data
	} else {
		// fallback to other response, have to support it by default
		return FallbackToFailed(name)
	}

	return http.StatusOK, response
}

// NotFound returns http response code and error response object
func NotFound(name string, errors []error) (int, ApiErrorResponse) {
	response, ok := errorResponseMap[name][StatusNotFound]
	if ok {
		response.Errors = errors
		if len(errors) == 1 {
			response.Data = errors[0].Error()
		}
	} else {
		// fallback to other response, have to support it by default
		return FallbackToFailedError(name, errors)
	}

	return http.StatusNotFound, response
}

// Found returns http response code and regular response object(found data and pagination)
func Found(name string, data interface{}, pagination interface{}) (int, ApiResponse) {
	response, ok := responseMap[name][StatusFound]
	if ok {
		response.Data = data
	} else {
		// fallback to other response, have to support it by default
		return FallbackToFailed(name)
	}

	if nil != pagination {
		dtoPagination := &Pagination{}
		fields.Сonvert(pagination, "pagination", dtoPagination)
		response.PaginationContainer = &PaginationContainer{Pagination: *dtoPagination}
	}

	return http.StatusOK, response
}

// Ok returns http response code and regular response object
func Ok(name string, data interface{}) (int, ApiResponse) {
	response, ok := responseMap[name][StatusOk]
	if ok {
		response.Data = data
	} else {
		// fallback to other response, have to support it by default
		return FallbackToFailed(name)
	}

	return http.StatusOK, response
}

// Failed returns http response code and error response object
func Failed(name string, errors []error) (int, ApiErrorResponse) {
	response, ok := errorResponseMap[name][StatusFailed]
	if ok {
		response.Errors = errors
		if len(errors) == 1 {
			response.Data = errors[0].Error()
		}
	} else {
		// fallback to other response, have to support it by default
		return FallbackToFailedError(name, errors)
	}

	return http.StatusInternalServerError, response
}

// FallbackToFailedError returns http response code and error response object as a fallback to predefined failed error response
func FallbackToFailedError(name string, errs []error) (int, ApiErrorResponse) {
	errs = append(errs, fmt.Errorf("fallback to failed - no proper response for '%s' type", name))
	response := errorResponseMap[TypeSystem][StatusFailed]
	response.Errors = errs
	if len(errs) == 1 {
		response.Data = errs[0].Error()
	}

	return http.StatusInternalServerError, response
}

// FallbackToFailed returns http response code and regular response object as a fallback to predefined failed response
func FallbackToFailed(name string) (int, ApiResponse) {
	response := responseMap[TypeSystem][StatusFailed]
	response.Data = fmt.Errorf("fallback to failed - no proper response for '%s' type", name).(interface{})

	return http.StatusInternalServerError, response
}