from __future__ import annotations

import json
from pathlib import Path

from .models import Timeline


def _srt_time(seconds: float) -> str:
    ms = int(round(max(0.0, seconds) * 1000))
    h, rem = divmod(ms, 3_600_000)
    m, rem = divmod(rem, 60_000)
    s, ms = divmod(rem, 1000)
    return f"{h:02}:{m:02}:{s:02},{ms:03}"


def _ass_time(seconds: float) -> str:
    centiseconds = int(round(max(0.0, seconds) * 100))
    h, rem = divmod(centiseconds, 360_000)
    m, rem = divmod(rem, 6_000)
    s, cs = divmod(rem, 100)
    return f"{h}:{m:02}:{s:02}.{cs:02}"


def write_json(timeline: Timeline, output: Path) -> Path:
    output.write_text(timeline.model_dump_json(indent=2), encoding="utf-8")
    return output


def write_words_json(timeline: Timeline, output: Path) -> Path:
    data = [word.model_dump() for word in timeline.words]
    output.write_text(json.dumps(data, ensure_ascii=False, indent=2), encoding="utf-8")
    return output


def write_accessibility_srt(timeline: Timeline, output: Path) -> Path:
    lines: list[str] = []
    for i, phrase in enumerate(timeline.phrases, 1):
        lines.extend([
            str(i),
            f"{_srt_time(phrase.start)} --> {_srt_time(phrase.end)}",
            phrase.text,
            "",
        ])
    output.write_text("\n".join(lines), encoding="utf-8-sig")
    return output


def _ass_escape(text: str) -> str:
    return text.replace("\\", r"\\").replace("{", r"\{").replace("}", r"\}")


def write_wordbeat_ass(
    timeline: Timeline,
    output: Path,
    *,
    width: int = 3840,
    height: int = 2160,
    font_name: str = "Arial",
    font_size: int = 92,
) -> Path:
    header = f"""[Script Info]
Title: WordBeat Phrase-Building Captions
ScriptType: v4.00+
PlayResX: {width}
PlayResY: {height}
WrapStyle: 2
ScaledBorderAndShadow: yes
YCbCr Matrix: TV.709

[V4+ Styles]
Format: Name, Fontname, Fontsize, PrimaryColour, SecondaryColour, OutlineColour, BackColour, Bold, Italic, Underline, StrikeOut, ScaleX, ScaleY, Spacing, Angle, BorderStyle, Outline, Shadow, Alignment, MarginL, MarginR, MarginV, Encoding
Style: WordBeat,{font_name},{font_size},&H00FFFFFF,&H0000FFFF,&H00101010,&H90000000,-1,0,0,0,100,100,0,0,3,5,0,2,180,180,145,1

[Events]
Format: Layer, Start, End, Style, Name, MarginL, MarginR, MarginV, Effect, Text
"""
    lines = [header.rstrip()]
    for i, event in enumerate(timeline.events):
        start = event.reveal_frame / timeline.fps
        if i + 1 < len(timeline.events):
            end = timeline.events[i + 1].reveal_frame / timeline.fps
        else:
            end = event.end_frame / timeline.fps
        end = max(end, start + 1.0 / timeline.fps)

        # Highlight only the newly added word while retaining the phrase.
        phrase_words = event.visible_text.split()
        prior = " ".join(phrase_words[:-1])
        current = phrase_words[-1] if phrase_words else event.word
        if prior:
            text = _ass_escape(prior) + " "
        else:
            text = ""
        pulse_ms = int(round(event.pulse_frames / timeline.fps * 1000))
        text += (
            r"{\c&H00FFFF&\fscx112\fscy112\t(0," + str(pulse_ms) +
            r",\c&HFFFFFF&\fscx100\fscy100)}" + _ass_escape(current)
        )
        lines.append(
            f"Dialogue: 0,{_ass_time(start)},{_ass_time(end)},WordBeat,,0,0,0,,{text}"
        )
    output.write_text("\n".join(lines) + "\n", encoding="utf-8-sig")
    return output