// Copyright © 2023 Roberto Hidalgo <event-gateway@un.rob.mx>
// SPDX-License-Identifier: Apache-2.0
package http

import (
	"encoding/json"
	"fmt"
	"io"
	"net/http"
	"strings"

	"git.rob.mx/nidito/event-gateway/internal/payload"
)

type Payload struct {
	Req      *http.Request
	resolved *payload.Payload
}

func (p *Payload) Parse() (*payload.Payload, error) {
	if p.resolved == nil {
		contentType := p.Req.Header.Get("Content-Type")
		if contentType == "" {
			contentType = "text/plain"
		} else {
			contentType = strings.SplitN(contentType, ";", 2)[0]
		}
		p.resolved = &payload.Payload{}

		switch contentType {
		case "text/plain":
			body, err := io.ReadAll(p.Req.Body)
			if err != nil {
				return p.resolved, fmt.Errorf("could not decode text/plain payload: %s", err)
			}
			if len(body) == 0 {
				return nil, nil
			}

			p.resolved.Kind = "text"
			p.resolved.Value = string(body)
		case "application/json":
			body, err := io.ReadAll(p.Req.Body)
			if err != nil {
				return p.resolved, fmt.Errorf("could not read json body: %s", err)
			}
			var data any
			if err := json.Unmarshal(body, &data); err != nil {
				return p.resolved, fmt.Errorf("could not decode json payload: %s", err)
			}
			p.resolved.Kind = "json"
			p.resolved.Value = data
		case "application/x-www-form-urlencoded":
			if err := p.Req.ParseForm(); err != nil {
				return p.resolved, fmt.Errorf("could not decode %s payload: %s", contentType, err)
			}
			log.Debugf("parsed form: %+v", p.Req.Form)

			form := map[string]any{}

			for key, values := range p.Req.PostForm {
				log.Debugf("parsing form: %s", key)
				if len(values) > 1 {
					form[key] = values
				} else {
					form[key] = p.Req.FormValue(key)
				}
			}
			p.resolved.Kind = "form"
			p.resolved.Value = form
		case "multipart/form-data":
			if err := p.Req.ParseMultipartForm(100); err != nil {
				if body, err := io.ReadAll(p.Req.Body); err == nil {
					log.Errorf("request %s body: %s", p.Req.Header["Content-Type"], body)
				}
				return p.resolved, fmt.Errorf("could not decode %s payload: %s", contentType, err)
			}

			form := map[string]any{}
			for key, values := range p.Req.MultipartForm.Value {
				if len(values) > 1 {
					form[key] = values
				} else {
					form[key] = p.Req.FormValue(key)
				}
			}
			p.resolved.Kind = "form"
			p.resolved.Value = form
		}
	}
	return p.resolved, nil
}