"""Concise console progress; does not depend on Unreal or its log format."""
import json
from pathlib import Path
import time


class ProgressDisplay:
    LABELS = {
        "starting": "Uruchamianie UE...",
        "preparing": "Przygotowywanie sceny i sekwencji...",
        "preparing_render": "Przygotowywanie renderu...",
        "rendering": "Renderowanie...",
        "encoding": "Render zakonczony. Skladanie MP4...",
        "closing": "Zamykanie UE...",
    }

    def __init__(self, events, clock=time.monotonic, emit=print):
        self.events = Path(events)
        self.clock, self.emit = clock, emit
        self.started = self.last_print = clock()
        self.position = 0
        self.pending = b""
        self.state = "starting"
        self.details = {}
        self.last_count = -1
        self.show(self.LABELS[self.state])

    def show(self, message):
        seconds = int(self.clock() - self.started)
        self.emit(f"[{seconds // 60:02d}:{seconds % 60:02d}] {message}", flush=True)
        self.last_print = self.clock()

    def update(self):
        try:
            with self.events.open("rb") as stream:
                stream.seek(self.position)
                self.pending += stream.read()
                self.position = stream.tell()
        except FileNotFoundError:
            pass
        while b"\n" in self.pending:
            line, self.pending = self.pending.split(b"\n", 1)
            try:
                event = json.loads(line)
            except (ValueError, UnicodeError):
                continue
            state = event.get("state")
            if state in self.LABELS:
                self.state, self.details = state, event
                self.last_count = -1
                self.show(self.LABELS[state])
        elapsed = self.clock() - self.last_print
        if self.state == "rendering" and elapsed >= 2:
            output = self.details.get("output")
            total = self.details.get("frames")
            if output and total:
                count = len(list((Path(output) / "frames").glob("frame_*.png")))
                if count != self.last_count and count > 0:
                    self.last_count = count
                    self.show(f"Renderowanie: {count}/{total} klatek zapisanych.")
                    return
        if elapsed >= 10:
            self.show(self.LABELS[self.state] + " Nadal pracuje.")