package server

import (
	"bytes"
	"encoding/json"
	"fmt"
	"log"
	"maps"
	"strconv"
)

type Response struct {
	StatusCode int
	Format     DataFormat
	Headers    map[string]string
	Payload    []byte
}

func NewStatusResponse(status int) *Response {
	return &Response{
		StatusCode: status,
		Headers:    make(map[string]string),
		Format: DataFormat{
			Format:   DF_BYTES,
			Encoding: "",
		},
		Payload: make([]byte, 0),
	}
}

func NewTextResponse(text string) *Response {
	return &Response{
		StatusCode: STATUS_SUCCESS,
		Headers:    make(map[string]string),
		Format: DataFormat{
			Format:   DF_TEXT,
			Encoding: E_UTF8,
		},
		Payload: []byte(text),
	}
}

func NewJsonResponse(data map[string]string) (*Response, error) {
	jsonBytes, err := json.Marshal(data)
	if err != nil {
		return nil, err
	}

	return &Response{
		StatusCode: STATUS_SUCCESS,
		Headers:    make(map[string]string),
		Format: DataFormat{
			Format:   DF_JSON,
			Encoding: E_UTF8,
		},
		Payload: jsonBytes,
	}, nil
}

func (res *Response) ToPacket() *Packet {
	headers := make(map[string]string)

	maps.Copy(headers, res.Headers)

	if res.Format.Format == DF_BYTES {
		headers[H_DATA_FORMAT] = DF_BYTES
	} else {
		headers[H_DATA_FORMAT] = fmt.Sprintf("%s:%s", res.Format.Format, res.Format.Encoding)
	}
	headers[H_STATUS] = strconv.Itoa(res.StatusCode)

	return BuildPacket(headers, res.Payload)
}

func (res *Response) AddHeader(key, value string) {
	if _, ok := res.Headers[key]; ok {
		log.Printf("WARN: Rewriting already existing header: '%s'\n", key)
	}
	res.Headers[key] = value
}

func (res *Response) Write(p []byte) (int, error) {
	buf := new(bytes.Buffer)

	n, err := buf.Write(p)
	if err != nil {
		return n, err
	}

	res.Payload = buf.Bytes()

	return n, err
}