#
# expand_paths.py <Peter.Bienstman@UGent.be>
#

import sys

from mnemosyne.libmnemosyne.filter import Filter
from mnemosyne.libmnemosyne.utils import expand_path


class ExpandPaths(Filter):

    """Fill out relative paths for src tags (e.g. img src or sound src)."""

    def run(self, text, card, fact_key, **render_args):
        text = self.expand_tag("src", text)
        text = self.expand_tag("data", text) # For Flash.
        return text

    def expand_tag(self, tag, text):
        # Add "=" to make sure we don't match "Application Data".
        i = text.lower().find(tag + "=")
        while i != -1:
            start = text.find("\"", i)
            end = text.find("\"", start + 1)
            if start == -1 or end == -1:
                break
            old_path = text[start+1:end]
            if not old_path.startswith("http:"):
                new_path = expand_path(old_path, self.database().media_dir())
                if sys.platform == "win32":
                    new_path = "/" + new_path.replace("\\", "/")
                text = text[:start+1] + "file://" + new_path + text[end:]
                if sys.platform == "win32" and tag == "data":
                    text = text.replace("file:///", "")
            # Since text is always longer now, we can start searching
            # from the previous end tag.
            i = text.lower().find(tag, end + 1)
        return text
