package server

import (
	"bufio"
	"errors"
	"strings"
)

type Request struct {
	Method      string
	URL         string
	HTTPVersion string
	Headers     map[string]string
	Body        string
}

var (
	ErrMalformedRequest = errors.New("malformed HTTP request")
	ErrInvalidMethod    = errors.New("invalid HTTP method")
)

func ParseRequest(reader *bufio.Reader) (*Request, error) {
	requestLine, err := reader.ReadString('\n')
	if err != nil {
		return nil, ErrMalformedRequest
	}

	requestLine = strings.TrimSpace(requestLine)
	if requestLine == "" {
		return nil, ErrMalformedRequest
	}

	parts := strings.Fields(requestLine)
	if len(parts) != 3 {
		return nil, ErrMalformedRequest
	}

	req := &Request{
		Method:      parts[0],
		URL:         parts[1],
		HTTPVersion: parts[2],
		Headers:     make(map[string]string),
	}

	for {
		headerLine, err := reader.ReadString('\n')
		if err != nil {
			break
		}

		headerLine = strings.TrimSpace(headerLine)
		if headerLine == "" {
			break
		}

		parts := strings.SplitN(headerLine, ":", 2)
		if len(parts) == 2 {
			key := strings.TrimSpace(parts[0])
			value := strings.TrimSpace(parts[1])
			req.Headers[key] = value
		}
	}

	return req, nil
}

func (r *Request) IsValid() bool {
	switch r.Method {
	case "GET", "POST", "PUT", "DELETE", "HEAD", "OPTIONS", "PATCH":
		return true
	default:
		return false
	}
}

func (r *Request) IsGET() bool {
	return r.Method == "GET"
}

func (r *Request) GetPath() string {
	if r.URL == "" || r.URL == "/" {
		return "/index.html"
	}

	path := strings.SplitN(r.URL, "?", 2)[0]
	if path == "/" {
		return "/index.html"
	}

	if strings.HasPrefix(path, "/") {
		return path
	}

	return "/" + path
}