import re
from datetime import timedelta

VTT_TIMECODE_PATTERN = (
    r"((?:\d{2}:)?\d{2}:\d{2}\.\d{3}) --> ((?:\d{2}:)?\d{2}:\d{2}\.\d{3})"
)
VTT_LINE_NUMBER_PATTERN = r"^\d+$"


def from_vtt(vtt_string):
    parts = re.split(r"\n\n+", vtt_string.strip())

    if parts[0].startswith("WEBVTT"):
        parts.pop(0)

    subtitles = []
    for part in parts:
        lines = part.split("\n")
        match = re.match(VTT_TIMECODE_PATTERN, lines[0])
        if not match:
            if re.match(VTT_LINE_NUMBER_PATTERN, lines[0]):
                lines.pop(0)
            match = re.match(VTT_TIMECODE_PATTERN, lines[0])
        if not match:
            continue

        start, end = match.groups()
        content = "\n".join(lines[1:])

        subtitles.append({"start": start, "end": end, "content": content})

    return subtitles


def to_vtt(subtitles):
    vtt_content = "WEBVTT\n\n"
    for idx, subtitle in enumerate(subtitles):
        start = subtitle["start"]
        end = subtitle["end"]
        content = subtitle["content"]
        vtt_content += f"{start} --> {end}\n{content}\n\n"
    return vtt_content.strip()


def stack_subtitle():
    buffer = []
    linebuf = []
    for line in parsed_vtt:
        print(line["content"].strip())
        content = line["content"].strip()
        if True:
            linebuf.append(line)
        else:
            linebuf.append(line)
            buffer.append(linebuf)
            linebuf = []

    sub = []
    for section in buffer:
        strbuf = ""
        for scene in section:
            strbuf += scene["content"]
            # if scene["content"][-1] == ".":
            strbuf += "\n"
            # else:
            # strbuf += " "
            scene["content"] = strbuf
            sub.append(scene)


with open("example.vtt", "r") as f:
    vtt_content = f.read()

parsed_vtt = from_vtt(vtt_content)
print(to_vtt(stack_subtitle(parsed_vtt)))