package responsex

// Author: Yun
// Version: 2023年6月12日19:25:54

import (
	"context"
	"encoding/json"
	"errors"
	"net/http"

	"github.com/yuninks/errorx"
	"github.com/yuninks/langx"
)

type response struct {
	Code       int         `json:"code"`
	Message    string      `json:"message"`
	Data       any         `json:"data,omitempty"`
	Pagination *Pagination `json:"pagination,omitempty"`
	TraceId    string      `json:"trace_id,omitempty"`
}

// 成功文案的多语言 key（独立 key，避免与 errorx 预注册的 "success" 冲突）
const successMsgKey = "responsex_success"

// 内置默认成功文案，也用作 defaultOptions 的初值
const defaultSuccessMessage = "请求成功"

// SuccessMessageCtx 按 ctx 语言解析成功文案：
//  1. 显式配置过 SetDefaultSuccessMessage → 用配置值；
//  2. 注册过 key "responsex_success" → 用该语言的译文；
//  3. 都没有 → 内置默认文案。
//
// 多语言接入示例（由调用方决定何时注册）：
//
//	langx.AppendCode(map[string]int{"responsex_success": 200})
//	langx.AppendTrans("zh", map[string]string{"responsex_success": "请求成功"})
//	langx.AppendTrans("en", map[string]string{"responsex_success": "success"})
//
// Success 系列内部使用同一套解析逻辑，无需额外配置。
func SuccessMessageCtx(ctx context.Context) string {
	return resolveSuccessMessage(ctx)
}

func resolveSuccessMessage(ctx context.Context) string {
	if op != nil && op.successMsgSet {
		return op.defaultSuccessMessage
	}
	if msg := langx.GetMsgCtx(ctx, successMsgKey); msg != successMsgKey {
		return msg
	}
	if op != nil {
		return op.defaultSuccessMessage
	}
	return defaultSuccessMessage
}

// Msg格式化响应
func FormatMessage(ctx context.Context, w http.ResponseWriter, msgKey string, format map[string]string, data interface{}, ops ...Option) {
	code, msg := langx.GetTransFormatCtx(ctx, msgKey, format)
	// langx v0.1 起「未知 key」的默认码是 -1（v0.0.x 是 200）。responsex 的成功码
	// 由 SetDefaultSuccessCode 决定，所以把默认码视为「没有业务码」，回落到它，
	// 保持与升级前一致的 code:200。
	if code == langx.GetDefaultCode() {
		code = op.defaultSuccessCode
	}
	baseOps := []Option{SetCode(code), SetMessage(msg), SetData(data)}
	baseOps = append(baseOps, ops...)
	ResponseCtx(ctx, w, baseOps...)
}

// 成功的响应
func Success(ctx context.Context, w http.ResponseWriter, data any, ops ...Option) {
	baseOps := []Option{SetCode(op.defaultSuccessCode), SetMessage(resolveSuccessMessage(ctx)), SetData(data)}
	baseOps = append(baseOps, ops...)
	ResponseCtx(ctx, w, baseOps...)
}

func SuccessWithPage(ctx context.Context, w http.ResponseWriter, data any, page *Pagination, ops ...Option) {
	baseOps := []Option{SetCode(op.defaultSuccessCode), SetMessage(resolveSuccessMessage(ctx)), SetData(data), SetPage(page)}
	baseOps = append(baseOps, ops...)
	ResponseCtx(ctx, w, baseOps...)
}

// 失败的响应
func Error(ctx context.Context, w http.ResponseWriter, err error, ops ...Option) {
	ErrorWithData(ctx, w, err, "", ops...)
}

func ErrorWithData(ctx context.Context, w http.ResponseWriter, err error, data interface{}, ops ...Option) {
	code := op.defaultErrorCode
	msg := "请求失败"
	if err != nil {
		// errorx v1.2 起错误值不再持有 context：错误常量只负责定义与构造，
		// 文案要在出口用 Msg(ctx) 按请求语言渲染，业务码用 GetCode() 取。
		var ei errorx.ErrorInterface
		if errors.As(err, &ei) {
			if bizCode := ei.GetCode(); langx.GetDefaultCode() != bizCode {
				code = bizCode
			}
			msg = ei.Msg(ctx)
		} else {
			msg = err.Error()
		}
	}
	baseOps := []Option{SetCode(code), SetMessage(msg), SetData(data)}
	baseOps = append(baseOps, ops...)
	ResponseCtx(ctx, w, baseOps...)
}

func ErrorStr(ctx context.Context, w http.ResponseWriter, msg string, ops ...Option) {
	translated := langx.GetMsgCtx(ctx, msg)
	// msg 命中语言表时按 key 取其业务码；未命中则保持默认错误码
	code := op.defaultErrorCode
	if translated != msg {
		if c := langx.GetCode(msg); c != langx.GetDefaultCode() {
			code = c
		}
	}
	baseOps := []Option{SetCode(code), SetMessage(translated)}
	baseOps = append(baseOps, ops...)
	ResponseCtx(ctx, w, baseOps...)
}

// 基础的响应
func ResponseCtx(ctx context.Context, w http.ResponseWriter, ops ...Option) {
	def := defaultOptions() // 默认值
	for _, o := range ops {
		o(def)
	}

	resp := response{}
	resp.Code = def.code
	resp.Message = def.message
	resp.Data = def.data
	resp.Pagination = def.pagination

	if def.traceFunc != nil {
		resp.TraceId = def.traceFunc(ctx)
	}

	bs, err := json.Marshal(resp)
	if err != nil {
		// 序列化失败不能回空 body，否则客户端无法解析
		logError(ctx, def, "response marshal failed err:%+v", err)
		fallback := response{
			Code:    op.defaultErrorCode,
			Message: "响应序列化失败",
		}
		if def.traceFunc != nil {
			fallback.TraceId = def.traceFunc(ctx)
		}
		bs, _ = json.Marshal(fallback)
		writeResponse(ctx, w, def, bs, http.StatusInternalServerError)
		return
	}

	if !def.ignoreLog {
		// 记录日志
		logInfo(ctx, def, "response:", string(bs))
	}

	writeResponse(ctx, w, def, bs, def.httpStatusCode)
}

// writeResponse 统一写响应，httpStatus 为 0 时按 200 处理
func writeResponse(ctx context.Context, w http.ResponseWriter, def *options, bs []byte, httpStatus int) {
	// 写入自定义响应头
	for k, v := range def.headers {
		w.Header().Set(k, v)
	}

	w.Header().Set("Content-Type", "application/json; charset=utf-8")

	if httpStatus == 0 {
		httpStatus = 200
	}
	w.WriteHeader(httpStatus)

	n, err := w.Write(bs)
	if err != nil || n != len(bs) {
		logError(ctx, def, "write response failed err:%+v", err)
	}
}

// logInfo / logError 使用本次响应的 logger（SetLogger 生效），并做空值保护
func logInfo(ctx context.Context, def *options, args ...interface{}) {
	if def == nil || def.logger == nil {
		return
	}
	def.logger.Info(ctx, args...)
}

func logError(ctx context.Context, def *options, format string, args ...interface{}) {
	if def == nil || def.logger == nil {
		return
	}
	def.logger.Errorf(ctx, format, args...)
}