from __future__ import annotations

from pathlib import Path
from .acoustic import chromaprint, similarity
from .arbitration import choose_winner, is_version_conflict, score
from .db import connect
from .constants import QUARANTINE_SUBDIR, TRASH_SUBDIR

MIN_SIMILARITY = 0.90
HIGH_SIMILARITY = 0.95
REVIEW_SIMILARITY = 0.80
DURATION_DELTA = 3.0


def _set_meta(conn, row, fp):
    conn.execute("UPDATE audio_tracks SET chromaprint=?,score=?,updated_at=CURRENT_TIMESTAMP WHERE id=?", (fp,score(row),row["id"]))


def find_candidates(conn,row):
    d=row["duration"]
    if d is None: return []
    return conn.execute("SELECT * FROM audio_tracks WHERE id!=? AND status IN ('active','hardlinked') AND duration IS NOT NULL AND duration BETWEEN ? AND ?", (row["id"],d-DURATION_DELTA,d+DURATION_DELTA)).fetchall()


def acoustic_dedupe(db_path: Path, root: Path) -> dict:
    stats={"checked":0,"equivalent":0,"review":0,"unique":0,"errors":0}
    with connect(db_path) as conn:
        rows=conn.execute("SELECT * FROM audio_tracks WHERE status='active' ORDER BY id").fetchall()
        for row in rows:
            if row["chromaprint"]: continue
            fp=chromaprint(Path(row["file_path"])); stats["checked"]+=1
            if not fp: stats["errors"]+=1; continue
            _set_meta(conn,row,fp)
            candidates=find_candidates(conn,row); best=None
            for c in candidates:
                if not c["chromaprint"]:
                    cfp=chromaprint(Path(c["file_path"]))
                    if cfp: _set_meta(conn,c,cfp); c=dict(c); c["chromaprint"]=cfp
                sim=similarity(fp,c["chromaprint"] or "")
                if sim>=REVIEW_SIMILARITY and (best is None or sim>best[0]): best=(sim,c)
            if not best or best[0]<REVIEW_SIMILARITY:
                stats["unique"]+=1; continue
            sim,c=best
            if sim<MIN_SIMILARITY or is_version_conflict(row,c):
                conn.execute("UPDATE audio_tracks SET status='review',review_status=?,updated_at=CURRENT_TIMESTAMP WHERE id=?",(f"similarity={sim:.3f}",row["id"]))
                stats["review"]+=1; continue
            winner=choose_winner([row,c]); loser=c if winner["id"]==row["id"] else row
            lp=Path(loser["file_path"]); wp=Path(winner["file_path"])
            if lp.exists() and wp.exists():
                trash=root/TRASH_SUBDIR
                trash.mkdir(parents=True,exist_ok=True)
                target=trash/lp.name
                n=1
                while target.exists(): target=trash/f"{lp.stem}.{n}{lp.suffix}"; n+=1
                lp.replace(target)
                conn.execute("UPDATE audio_tracks SET status='trashed',file_path=?,trashed_at=CURRENT_TIMESTAMP,review_status=?,updated_at=CURRENT_TIMESTAMP WHERE id=?",(str(target),f"equivalent={sim:.3f};winner={wp}",loser["id"]))
                stats["equivalent"]+=1
    return stats