#!/usr/bin/env python3
"""
Build an enhanced transcript that interleaves audio segments (from a
whisperx JSON) with screen frames sourced from a cht session's
frames/index.json. Frames are placed at their real timestamps rather
than appended at the end.

Usage:
    python ctrl/cht/interleave_cht_frames.py \\
        <transcript.json> <cht_frames_index.json> [output.txt]
"""
import json
import sys
from pathlib import Path


def fmt_ts(seconds: float) -> str:
    seconds = int(seconds)
    return f"{seconds // 60:02d}:{seconds % 60:02d}"


def load_audio(transcript_json: Path):
    data = json.loads(transcript_json.read_text())
    out = []
    for s in data.get("segments", []):
        out.append({
            "type": "audio",
            "ts": float(s.get("start", 0)),
            "speaker": s.get("speaker"),
            "text": (s.get("text") or "").strip(),
        })
    return out


def load_frames(index_json: Path):
    data = json.loads(index_json.read_text())
    out = []
    for f in data:
        out.append({
            "type": "frame",
            "ts": float(f["timestamp"]),
            "path": f["path"],
            "id": f.get("id", ""),
        })
    return out


def merge(audio, frames):
    events = sorted(audio + frames, key=lambda e: e["ts"])
    grouped = []
    cur = None
    for e in events:
        if e["type"] == "frame":
            if cur:
                grouped.append(cur)
                cur = None
            grouped.append(e)
        else:
            if cur and cur.get("speaker") == e["speaker"]:
                cur["text"] += " " + e["text"]
            else:
                if cur:
                    grouped.append(cur)
                cur = {
                    "type": "audio",
                    "ts": e["ts"],
                    "speaker": e["speaker"],
                    "text": e["text"],
                }
    if cur:
        grouped.append(cur)
    return grouped


def render(grouped):
    lines = [
        "=" * 80,
        "ENHANCED MEETING TRANSCRIPT",
        "Audio transcript + Screen frames (interleaved by timestamp)",
        "=" * 80,
        "",
    ]
    for e in grouped:
        ts = fmt_ts(e["ts"])
        if e["type"] == "frame":
            lines.append(f"[{ts}] SCREEN CONTENT:")
            lines.append(f"  Frame: {e['path']}")
        else:
            spk = e["speaker"] or "UNKNOWN"
            lines.append(f"[{ts}] {spk}:")
            lines.append(f"  {e['text']}")
        lines.append("")
    return "\n".join(lines)


def main():
    if len(sys.argv) < 3:
        print(__doc__, file=sys.stderr)
        sys.exit(2)
    transcript = Path(sys.argv[1])
    frames_index = Path(sys.argv[2])
    output = Path(sys.argv[3]) if len(sys.argv) >= 4 else None

    audio = load_audio(transcript)
    frames = load_frames(frames_index)
    grouped = merge(audio, frames)

    text = render(grouped)
    if output:
        output.write_text(text)
        print(f"Wrote {output}")
        print(f"  audio segments in : {len(audio)}")
        print(f"  frames in         : {len(frames)}")
        print(f"  output blocks     : {len(grouped)}")
    else:
        sys.stdout.write(text)


if __name__ == "__main__":
    main()