Add existing code

diff --git a/cbs.py b/cbs.py
new file mode 100755 (executable)
index 0000000..e76ce82
--- /dev/null
+++ b/cbs.py
@@ -0,0 +1,129 @@
+#!/usr/bin/env python3
+
+import socket, ssl, urllib
+import PySimpleGUI as sg
+
+
+# ------------------------------------------------------------------------------
+# Settings
+
+
+homepage = 'gemini://medusae.space/index.gmi'
+
+preform_font = 'courier 10'
+preform_color = 'gray'
+
+content_font = 'helvetica 10'
+content_color = 'black'
+
+link_font = content_font
+link_color = 'blue'
+
+list_font = content_font
+list_color = content_color
+
+h3_font = 'helvetica 14'
+h3_color = 'green'
+h2_font = 'helvetica 18'
+h2_color = 'green'
+h1_font = 'helvetica 22'
+h1_color = 'green'
+
+
+# ------------------------------------------------------------------------------
+
+
+def gemini_request(url):
+    parsed = urllib.parse.urlparse(url)
+    ctxt = ssl.create_default_context()
+    ctxt.check_hostname = False
+    ctxt.verify_mode = ssl.CERT_NONE
+
+    with socket.create_connection((parsed.hostname, parsed.port or 1965)) as sock:
+        with ctxt.wrap_socket(sock, server_hostname=parsed.hostname) as ssock:
+            ssock.write((url + '\r\n').encode('utf-8'))
+            resp = b''
+            while data := ssock.recv(4096):
+                resp += data
+            return resp
+
+
+def browser_window_layout():
+    return [
+        [sg.Button('Back'), sg.Button('Forward'), sg.Text('URL:'), sg.InputText(homepage, key='-URL-'), sg.Button('Go'), sg.Button('Home')],
+        [sg.Multiline(size=(100, 100), expand_x=True, expand_y=True, write_only=True, key='-CONTENT-')]
+    ]
+
+
+def update_content(window):
+    is_format = True
+    window['-CONTENT-'].update('')
+    content = gemini_request(window['-URL-'].get()).decode('utf-8')
+    for line in content.splitlines(keepends=True):
+        if line.startswith('```'):
+            is_format = not is_format
+            continue
+        if not is_format:
+            window['-CONTENT-'].update(line, text_color_for_value=preform_color, font_for_value=preform_font, append=True)
+        elif line.startswith('=> '):
+            window['-CONTENT-'].update(line, text_color_for_value=link_color, font_for_value=link_font, append=True)
+        elif line.startswith('# '):
+            window['-CONTENT-'].update(line[2:], text_color_for_value=h1_color, font_for_value=h1_font, append=True)
+        elif line.startswith('## '):
+            window['-CONTENT-'].update(line[3:], text_color_for_value=h2_color, font_for_value=h2_font, append=True)
+        elif line.startswith('###'):
+            window['-CONTENT-'].update(line[4:], text_color_for_value=h3_color, font_for_value=h3_font, append=True)
+        elif line.startswith('* '):
+            window['-CONTENT-'].update(line, text_color_for_value=list_color, font_for_value=list_font, append=True)
+        else:
+            window['-CONTENT-'].update(line, text_color_for_value=content_color, font_for_value=content_font, append=True)
+
+
+class History(object):
+    def __init__(self):
+        self._hist = []
+        self._i = -1
+
+    def back(self):
+        if len(self._hist) > -self._i:
+            self._i -= 1
+            return self._hist[self._i]
+
+    def forward(self):
+        if self._i < -1:
+            self._i += 1
+            return self._hist[self._i]
+
+    def add(self, url):
+        if self._i < -1: self._hist = self._hist[:self._i+1]
+        self._i = -1
+        self._hist.append(url)
+
+
+def main():
+    window = sg.Window('Gemini Client', browser_window_layout(), resizable=True)
+    hist = History()
+    hist.add(window['-URL-'].get())
+    window.finalize()
+    update_content(window)
+    while True:
+        event, values = window.read()
+        print(event, values)
+        if event == sg.WIN_CLOSED:
+            break
+        else:
+            if event == 'Go':
+                hist.add(values['-URL-'])
+            elif event == 'Back':
+                if url := hist.back():
+                    window['-URL-'].update(url)
+            elif event == 'Forward':
+                if url := hist.forward():
+                    window['-URL-'].update(url)
+            elif event == 'Home':
+                window['-URL-'].update(homepage)
+            update_content(window)
+
+
+if __name__ == '__main__':
+    main()