Fix T56372: Properly show error messages when submission fails

This also introduces a word-wrapping function that takes variable character
widths into account.

benchmark/space/draw.py

@@ -4,11 +4,12 @@ import blf
 import bpy
 
 from ..foundation import util
+from ..submission.client import CommunicationError
 
 from . import G
 
 
-WELCOME_TEXT = "Run the Quick Benchmark on the selected device to\n" \
+WELCOME_TEXT = "Run the Quick Benchmark on the selected device to " \
                "get a fast measurement of your hardware's performance.\n" \
                "Usually takes less than 30 minutes."
 
@@ -147,7 +148,9 @@ def _draw_introduction(image_y, ui_scale, window_width, window_height):
     x = 50.0 * ui_scale
     y = image_y - (image_y - 52 * ui_scale - 18 * 3 * ui_scale) * 0.5
     blf.size(font_id, int(12 * ui_scale), 72)
-    draw_text_multiline(WELCOME_TEXT, x, y)
+
+    text = word_wrap(WELCOME_TEXT, window_width * 0.45)
+    draw_text_multiline(text, x, y)
 
 
 def _draw_benchmark_is_running(image_y, result_platform, result_stats, ui_scale, window_width):
@@ -208,4 +211,74 @@ def _draw_benchmark_has_run(image_y, ui_scale, window_width, window_height):
     x = 50.0 * ui_scale
     y = image_y - (image_y - 52 * ui_scale - 18 * 3 * ui_scale) * 0.5
     blf.size(font_id, int(12 * ui_scale), 72)
-    draw_text_multiline(BLURB_TEXT, x, y)
+
+    text = _after_submission_text()
+    text = word_wrap(text, window_width * 0.45)
+    draw_text_multiline(text, x, y)
+
+
+def _after_submission_text() -> str:
+    ex = G.submission_exception
+
+    # Nothing wrong, just show the default text.
+    if not ex:
+        return BLURB_TEXT
+
+    # If not our own exception class, show generic message.
+    if not isinstance(ex, CommunicationError):
+        return f'Error submitting your results: {ex}'
+
+    # Return proper message based on the HTTP status code of the response.
+    if ex.status_code in {502, 503}:
+        # 502 Bad Gateway, happens when restarting uWSGI.
+        # 503 Service Unavailable, happens when OpenData is down.
+        text = f'There was a hickups with code {ex.status_code} ' \
+               f'in the Open Data platform, please try submitting again.'
+    elif ex.status_code == 422:
+        # 422 Unprocessable Entity, happens when the JSON doesn't pass schema validation.
+        text = f'We somehow submitted invalid data, see below for details.'
+    else:
+        text = f'Error {ex.status_code} submitting your results.'
+
+    if not ex.json:
+        return text
+
+    msg = ex.json.get('message')
+    if msg:
+        return f'{text}\nThe server said: {msg}'
+    return text
+
+
+def word_wrap(string: str, width_in_px: int) -> str:
+    """Word-wrapping with variable character width.
+
+    Newlines in the input string are kept in the output.
+    """
+
+    if '\n' in string:
+        # If the string already consists of multiple lines, wrap each line individually.
+        return '\n'.join(word_wrap(line, width_in_px)
+                         for line in string.splitlines(keepends=False))
+
+    # Do an estimate of the maximum number of characters to fit on a line.
+    char_width = blf.dimensions(font_id, "i")[0]
+    max_chars = int(width_in_px // char_width)
+
+    wrapped_lines = []
+    while string:
+        # The line won't be longer than max_chars, so start there.
+        candidate_line = string[:max_chars]
+        line_width = blf.dimensions(font_id, candidate_line)[0]
+
+        # Keep removing the last word until the line fits the width.
+        while line_width >= width_in_px:
+            marker = len(candidate_line) - 1
+            while not candidate_line[marker].isspace():
+                marker -= 1
+            candidate_line = candidate_line[:marker]
+            line_width = blf.dimensions(font_id, candidate_line)[0]
+
+        string = string[len(candidate_line):]
+        wrapped_lines.append(candidate_line.strip())
+
+    return '\n'.join(wrapped_lines)