1//
  2// Copyright (c) 2019 Ted Unangst <tedu@tedunangst.com>
  3//
  4// Permission to use, copy, modify, and distribute this software for any
  5// purpose with or without fee is hereby granted, provided that the above
  6// copyright notice and this permission notice appear in all copies.
  7//
  8// THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
  9// WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 10// MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 11// ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 12// WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 13// ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 14// OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 15
 16package main
 17
 18import (
 19	"bufio"
 20	"bytes"
 21	"crypto/sha512"
 22	"fmt"
 23	"image"
 24	"image/png"
 25	"log"
 26	"net/http"
 27	"regexp"
 28	"strconv"
 29	"strings"
 30
 31	"github.com/gorilla/mux"
 32)
 33
 34var avatarcolors = [4][4]byte{
 35	{16, 0, 48, 255},
 36	{48, 0, 96, 255},
 37	{72, 0, 144, 255},
 38	{96, 0, 192, 255},
 39}
 40
 41func loadAvatarColors() {
 42	var colors string
 43	getconfig("avatarcolors", &colors)
 44	if colors == "" {
 45		return
 46	}
 47	r := bufio.NewReader(strings.NewReader(colors))
 48	for i := 0; i < 4; i++ {
 49		l, _ := r.ReadString(' ')
 50		for l == " " {
 51			l, _ = r.ReadString(' ')
 52		}
 53		l = strings.Trim(l, "# \n")
 54		if len(l) == 6 {
 55			l = l + "ff"
 56		}
 57		c, err := strconv.ParseUint(l, 16, 32)
 58		if err != nil {
 59			log.Printf("error reading avatar color %d: %s", i, err)
 60			continue
 61		}
 62		avatarcolors[i][0] = byte(c >> 24 & 0xff)
 63		avatarcolors[i][1] = byte(c >> 16 & 0xff)
 64		avatarcolors[i][2] = byte(c >> 8 & 0xff)
 65		avatarcolors[i][3] = byte(c >> 0 & 0xff)
 66	}
 67}
 68
 69func genAvatar(name string, hex bool) []byte {
 70	h := sha512.New()
 71	h.Write([]byte(name))
 72	s := h.Sum(nil)
 73	img := image.NewNRGBA(image.Rect(0, 0, 64, 64))
 74	for i := 0; i < 64; i++ {
 75		for j := 0; j < 64; j++ {
 76			p := i*img.Stride + j*4
 77			if hex {
 78				tan := 0.577
 79				if i < 32 {
 80					if j < 17-int(float64(i)*tan) || j > 46+int(float64(i)*tan) {
 81						img.Pix[p+0] = 0
 82						img.Pix[p+1] = 0
 83						img.Pix[p+2] = 0
 84						img.Pix[p+3] = 255
 85						continue
 86					}
 87				} else {
 88					if j < 17-int(float64(64-i)*tan) || j > 46+int(float64(64-i)*tan) {
 89						img.Pix[p+0] = 0
 90						img.Pix[p+1] = 0
 91						img.Pix[p+2] = 0
 92						img.Pix[p+3] = 255
 93						continue
 94
 95					}
 96				}
 97			}
 98			xx := i/16*16 + j/16
 99			x := s[xx]
100			if x < 64 {
101				img.Pix[p+0] = avatarcolors[0][0]
102				img.Pix[p+1] = avatarcolors[0][1]
103				img.Pix[p+2] = avatarcolors[0][2]
104				img.Pix[p+3] = avatarcolors[0][3]
105			} else if x < 128 {
106				img.Pix[p+0] = avatarcolors[1][0]
107				img.Pix[p+1] = avatarcolors[1][1]
108				img.Pix[p+2] = avatarcolors[1][2]
109				img.Pix[p+3] = avatarcolors[1][3]
110			} else if x < 192 {
111				img.Pix[p+0] = avatarcolors[2][0]
112				img.Pix[p+1] = avatarcolors[2][1]
113				img.Pix[p+2] = avatarcolors[2][2]
114				img.Pix[p+3] = avatarcolors[2][3]
115			} else {
116				img.Pix[p+0] = avatarcolors[3][0]
117				img.Pix[p+1] = avatarcolors[3][1]
118				img.Pix[p+2] = avatarcolors[3][2]
119				img.Pix[p+3] = avatarcolors[3][3]
120			}
121		}
122	}
123	var buf bytes.Buffer
124	png.Encode(&buf, img)
125	return buf.Bytes()
126}
127
128func showflag(writer http.ResponseWriter, req *http.Request) {
129	code := mux.Vars(req)["code"]
130	colors := strings.Split(code, ",")
131	numcolors := len(colors)
132	vert := false
133	if colors[0] == "vert" {
134		vert = true
135		colors = colors[1:]
136		numcolors--
137		if numcolors == 0 {
138			http.Error(writer, "bad flag", 400)
139			return
140		}
141	}
142	pixels := make([][4]byte, numcolors)
143	for i := 0; i < numcolors; i++ {
144		hex := colors[i]
145		if len(hex) == 3 {
146			hex = fmt.Sprintf("%c%c%c%c%c%c",
147				hex[0], hex[0], hex[1], hex[1], hex[2], hex[2])
148		}
149		c, _ := strconv.ParseUint(hex, 16, 32)
150		r := byte(c >> 16 & 0xff)
151		g := byte(c >> 8 & 0xff)
152		b := byte(c >> 0 & 0xff)
153		pixels[i][0] = r
154		pixels[i][1] = g
155		pixels[i][2] = b
156		pixels[i][3] = 255
157	}
158
159	h := 128
160	w := h * 3 / 2
161	img := image.NewRGBA(image.Rect(0, 0, w, h))
162	if vert {
163		for j := 0; j < w; j++ {
164			pix := pixels[j*numcolors/w][:]
165			for i := 0; i < h; i++ {
166				p := i*img.Stride + j*4
167				copy(img.Pix[p:], pix)
168			}
169		}
170	} else {
171		for i := 0; i < h; i++ {
172			pix := pixels[i*numcolors/h][:]
173			for j := 0; j < w; j++ {
174				p := i*img.Stride + j*4
175				copy(img.Pix[p:], pix)
176			}
177		}
178	}
179
180	writer.Header().Set("Cache-Control", "max-age="+somedays())
181	png.Encode(writer, img)
182}
183
184var re_flags = regexp.MustCompile("flag:[[:alnum:],]+")
185
186func fixupflags(h *Honk) []Emu {
187	var emus []Emu
188	count := 0
189	h.Noise = re_flags.ReplaceAllStringFunc(h.Noise, func(m string) string {
190		count++
191		var e Emu
192		e.Name = fmt.Sprintf(":flag%d:", count)
193		e.ID = fmt.Sprintf("https://%s/flag/%s", serverName, m[5:])
194		emus = append(emus, e)
195		return e.Name
196	})
197	return emus
198}
199
200func renderflags(h *Honk) {
201	h.Noise = re_flags.ReplaceAllStringFunc(h.Noise, func(m string) string {
202		code := m[5:]
203		src := fmt.Sprintf("https://%s/flag/%s", serverName, code)
204		return fmt.Sprintf(`<img class="emu" title="%s" src="%s">`, "flag", src)
205	})
206}