"""Progress/reporting shim.

The pipeline in `inference.py` and `vectorize.py` is ported from the FraXtex QGIS
plugin, where every algorithm receives a `QgsProcessingFeedback`. Keeping the same
call surface here is what lets the two implementations stay diffable: the ported
code is identical apart from its imports, and this object absorbs the difference
between a QGIS progress dialog and a Gradio one.

See CLAUDE.md: qfraxtex is canonical for pipeline logic.
"""


class FatalError(RuntimeError):
    """Raised by `reportError(..., fatalError=True)`.

    In QGIS the algorithm returns `{}` after reporting; here the caller is a Gradio
    handler, so an exception is the equivalent way to abandon the run and surface
    the message to the user.
    """


class Feedback:
    """Collects log lines and forwards progress to an optional Gradio progress bar."""

    def __init__(self, progress=None):
        self._progress = progress
        self.messages = []
        self.warnings = []

    def pushInfo(self, text):
        self.messages.append(str(text))

    def pushWarning(self, text):
        text = str(text)
        self.warnings.append(text)
        self.messages.append(f"⚠️ {text}")

    def reportError(self, text, fatalError=False):
        text = str(text)
        self.messages.append(f"❌ {text}")
        if fatalError:
            raise FatalError(text)

    def isCanceled(self):
        # Gradio has no cancellation signal that reaches a running handler.
        return False

    def setProgress(self, percent):
        if self._progress is not None:
            self._progress(percent / 100.0)

    def log(self):
        return "\n".join(self.messages)