From 39e0eb5d6d6ca9fa5b398463a353b19456a27511 Mon Sep 17 00:00:00 2001
From: Ken Kinder <ken+github@kkinder.com>
Date: Sun, 16 Jun 2024 15:00:07 +0100
Subject: [PATCH] Fix micropython issue where urls were not being parsed

---
 examples/tutorial/10_full_app/pages.py |  2 +
 puepy/router.py                        | 58 +++++++++++++++++++++++++-
 tests/test_router.py                   | 47 ++++++++++++++++++++-
 3 files changed, 104 insertions(+), 3 deletions(-)

diff --git a/examples/tutorial/10_full_app/pages.py b/examples/tutorial/10_full_app/pages.py
index 87dab11..6592f26 100644
--- a/examples/tutorial/10_full_app/pages.py
+++ b/examples/tutorial/10_full_app/pages.py
@@ -128,6 +128,8 @@ def populate(self):
                 t.sl_button("Login", type="submit")
                 t.p("Use any username or password")
 
+                t.p(f"You will be returned to {self.return_to}")
+
     def on_submit(self, event):
         event.preventDefault()
         if self.refs["form"].element.checkValidity():
diff --git a/puepy/router.py b/puepy/router.py
index 0e68592..ec1a7f2 100644
--- a/puepy/router.py
+++ b/puepy/router.py
@@ -3,6 +3,57 @@
 from .util import mixed_to_underscores, jsobj
 
 
+def _micropython_parse_query_string(query_string):
+    """
+    In MicroPython, urllib isn't available and we can't use the JavaScript library:
+    https://github.com/pyscript/pyscript/issues/2100
+    """
+    if query_string and query_string[0] == "?":
+        query_string = query_string[1:]
+
+    def url_decode(s):
+        # Decode URL-encoded characters without using regex, which is also pretty broken in MicroPython...
+        i = 0
+        length = len(s)
+        decoded = []
+
+        while i < length:
+            if s[i] == "%":
+                if i + 2 < length:
+                    hex_value = s[i + 1 : i + 3]
+                    decoded.append(chr(int(hex_value, 16)))
+                    i += 3
+                else:
+                    decoded.append("%")
+                    i += 1
+            elif s[i] == "+":
+                decoded.append(" ")
+                i += 1
+            else:
+                decoded.append(s[i])
+                i += 1
+
+        return "".join(decoded)
+
+    params = {}
+    for part in query_string.split("&"):
+        if "=" in part:
+            key, value = part.split("=", 1)
+            key = url_decode(key)
+            value = url_decode(value)
+            if key in params:
+                params[key].append(value)
+            else:
+                params[key] = [value]
+        else:
+            key = url_decode(part)
+            if key in params:
+                params[key].append("")
+            else:
+                params[key] = ""
+    return params
+
+
 if platform == PLATFORM_MICROPYTHON:
     from js import encodeURIComponent
 
@@ -18,6 +69,9 @@ def url_quote(s):
     def parse_query_string(qs):
         return parse_qs(urlparse(qs).query)
 
+elif platform == PLATFORM_MICROPYTHON:
+    parse_query_string = _micropython_parse_query_string
+
 else:
     import js
 
@@ -142,8 +196,8 @@ def match(self, path):
     def navigate_to_path(self, path, **kwargs):
         if isinstance(path, type) and issubclass(path, Page):
             path = self.reverse(path, **kwargs)
-        else:
-            path = path + "?" + "&".join(f"{url_quote(k)}={url_quote(v)}" for k, v in kwargs.items())
+        elif kwargs:
+            path += "?" + "&".join(f"{url_quote(k)}={url_quote(v)}" for k, v in kwargs.items())
 
         if self.link_mode == self.LINK_MODE_DIRECT:
             window.location = path
diff --git a/tests/test_router.py b/tests/test_router.py
index 04a8c26..84c5e13 100644
--- a/tests/test_router.py
+++ b/tests/test_router.py
@@ -1,7 +1,7 @@
 import unittest
 
 from puepy.core import Page
-from puepy.router import Router, Route
+from puepy.router import Router, Route, _micropython_parse_query_string
 
 
 class TestRoute(unittest.TestCase):
@@ -90,5 +90,50 @@ def test_no_match_route(self):
         self.assertIsNone(params)
 
 
+class TestMicropythonParseQueryString(unittest.TestCase):
+    def test_simple_query(self):
+        query_string = "?name=John"
+        expected_output = {"name": ["John"]}
+        self.assertEqual(_micropython_parse_query_string(query_string), expected_output)
+
+    def test_multiple_params(self):
+        query_string = "?name=John&age=30"
+        expected_output = {"name": ["John"], "age": ["30"]}
+        self.assertEqual(_micropython_parse_query_string(query_string), expected_output)
+
+    def test_url_encoded_chars(self):
+        query_string = "?name=John%20Doe&age=30"
+        expected_output = {"name": ["John Doe"], "age": ["30"]}
+        self.assertEqual(_micropython_parse_query_string(query_string), expected_output)
+
+    def test_repeated_params(self):
+        query_string = "?name=John&name=Jane"
+        expected_output = {"name": ["John", "Jane"]}
+        self.assertEqual(_micropython_parse_query_string(query_string), expected_output)
+
+    def test_no_value_param(self):
+        query_string = "?name="
+        expected_output = {"name": [""]}
+        self.assertEqual(_micropython_parse_query_string(query_string), expected_output)
+
+    def test_no_value_multiple_params(self):
+        query_string = "?name=&age="
+        expected_output = {"name": [""], "age": [""]}
+        self.assertEqual(_micropython_parse_query_string(query_string), expected_output)
+
+    def test_plus_as_space(self):
+        query_string = "?name=John+Doe&age=30"
+        expected_output = {"name": ["John Doe"], "age": ["30"]}
+        self.assertEqual(_micropython_parse_query_string(query_string), expected_output)
+
+    def test_single_param_without_value(self):
+        query_string = "?name"
+        expected_output = {"name": ""}
+        self.assertEqual(_micropython_parse_query_string(query_string), expected_output)
+
+
+if __name__ == "__main__":
+    unittest.main()
+
 if __name__ == "__main__":
     unittest.main()