package gemini

import (
	"crypto/tls"
	"fmt"
	"net/url"
	"os"
	"strconv"
	"strings"
)

const GeminiNetwork = "tcp"
const GeminiPort = 1965
const GeminiPrefix = "gemini://"
const requestSuffix = "\r\n"

type GeminiURI struct {
	host    string
	request []byte
}

func Parse(request, host string, port int) (*GeminiURI, error) {
	// add gemini:// scheme if missing
	if !strings.HasPrefix(request, GeminiPrefix) {
		request = GeminiPrefix + request
	}

	// create GeminiURI if host has been specified
	if strings.Contains(host, ":") {
		return &GeminiURI{host, []byte(request + requestSuffix)}, nil
	} else if host != "" {
		return &GeminiURI{host + ":" + strconv.Itoa(port), []byte(request + requestSuffix)}, nil
	}

	// get host from request
	u, err := url.Parse(request)
	if err != nil {
		return nil, err
	}

	if strings.Contains(u.Host, ":") {
		return &GeminiURI{u.Host, []byte(request + requestSuffix)}, nil
	} else {
		return &GeminiURI{u.Host + ":" + strconv.Itoa(port), []byte(request + requestSuffix)}, nil
	}
}

func (c *GeminiURI) Get(config *tls.Config, out *os.File) error {
	conn, err := tls.Dial(GeminiNetwork, c.host, config)
	if err != nil {
		return err
	}
	defer conn.Close()

	n, err := conn.Write(c.request)
	if err != nil {
		return err
	}

	buf := make([]byte, 1024)

	for {
		n, err = conn.Read(buf)
		if err != nil {
			return err
		}
		written, err := out.Write(buf[:n])
		if written != n {
			return fmt.Errorf("Got %d bytes, but only wrote %d bytes", n, written)
		}
		if err != nil {
			return err
		}

		if n == 0 {
			break
		}
	}
	return nil
}