Recreate Python build script

.gitignore

@@ -1,5 +1,6 @@
 # Output
-out.pac
+*.pac
+dist/
 
 # Python
 __pycache__/

build.py

@@ -0,0 +1,56 @@
+#!/usr/bin/python3
+
+import os
+from datetime import datetime
+import ipaddress
+import requests
+from requests.exceptions import RequestException, HTTPError
+
+
+SOURCES = {
+    'ipdeny.com': 'http://www.ipdeny.com/ipblocks/data/aggregated/cn-aggregated.zone',
+    '17mon': 'https://raw.githubusercontent.com/17mon/china_ip_list/master/china_ip_list.txt',
+}
+OUT_DIR = "dist"
+
+
+def fetch_and_convert(src):
+    response = requests.get(src)
+    response.raise_for_status()
+    template = "var CHINA = [\n{}\n];\n"
+    lines = []
+    for iprange in response.text.strip().split("\n"):
+        ipnet = ipaddress.IPv4Network(iprange)
+        netaddr = int(ipnet.network_address)
+        netmask = int(ipnet.netmask)
+        s = f"  [0x{netaddr:08X}, 0x{netmask:08X}], // {iprange}"
+        lines.append(s)
+    lines.append("  [0xFFFFFFFF, 0xFFFFFFFF]  // 255.255.255.255/32")  # use broadcast as a placeholder
+    return template.format("\n".join(lines))
+
+
+def main():
+    now = datetime.utcnow()
+    date = now.strftime("%Y%m%d")
+    with open("code.js", "r") as f:
+        code = f.read()
+    code = code.replace("@@TIME@@", now.isoformat()[:-7])
+
+    if not os.path.exists(OUT_DIR):
+        os.mkdir(OUT_DIR, mode=0o755)
+    for key in SOURCES:
+        print(f"Generating PAC script from source {key}")
+        try:
+            data = fetch_and_convert(SOURCES[key])
+        except RequestException:
+            continue
+        except HTTPError:
+            continue
+        filename = f"pac-{date}-{key}.txt"
+        with open(os.path.join(OUT_DIR, filename), "w") as f:
+            f.write(code)
+            f.write(data)
+
+
+if __name__ == '__main__':
+    main()