import os
import time
import logging
from typing import List, Dict, Any, Optional

import numpy as np
import psycopg2
import psycopg2.extras

logging.basicConfig(
    level=logging.INFO,
    format='[eventos] %(asctime)s %(levelname)s: %(message)s'
)
log = logging.getLogger(__name__)

DB = dict(
    host=os.environ.get("DB_HOST", "localhost"),
    port=int(os.environ.get("DB_PORT", 5432)),
    dbname=os.environ.get("DB_NAME", "rss"),
    user=os.environ.get("DB_USER", "rss"),
    password=os.environ.get("DB_PASS", "x"),
)

EVENT_LANGS = [
    s.strip().lower()
    for s in os.environ.get("EVENT_LANGS", "es").split(",")
    if s.strip()
]

EVENT_BATCH_IDS = int(os.environ.get("EVENT_BATCH_IDS", "200"))
EVENT_SLEEP_IDLE = float(os.environ.get("EVENT_SLEEP_IDLE", "5.0"))
EVENT_DIST_THRESHOLD = float(os.environ.get("EVENT_DIST_THRESHOLD", "0.25"))


def get_conn():
    return psycopg2.connect(**DB)


def ensure_schema(conn):
    with conn.cursor() as cur:
        cur.execute(
            """
            CREATE TABLE IF NOT EXISTS eventos (
                id SERIAL PRIMARY KEY,
                creado_en     TIMESTAMP NOT NULL DEFAULT NOW(),
                actualizado_en TIMESTAMP NOT NULL DEFAULT NOW(),
                centroid      JSONB NOT NULL,
                total_traducciones INTEGER NOT NULL DEFAULT 1
            );
            """
        )
        cur.execute(
            """
            ALTER TABLE traducciones
            ADD COLUMN IF NOT EXISTS evento_id INTEGER REFERENCES eventos(id);
            """
        )
        cur.execute(
            """
            CREATE INDEX IF NOT EXISTS idx_traducciones_evento
                ON traducciones(evento_id);
            """
        )
        cur.execute(
            """
            CREATE INDEX IF NOT EXISTS idx_traducciones_evento_fecha
                ON traducciones(evento_id, noticia_id);
            """
        )
        cur.execute(
            """
            CREATE OR REPLACE FUNCTION actualizar_evento_modificado()
            RETURNS TRIGGER AS $$
            BEGIN
                NEW.actualizado_en = NOW();
                RETURN NEW;
            END;
            $$ LANGUAGE plpgsql;
            """
        )
        cur.execute("DROP TRIGGER IF EXISTS trg_evento_modificado ON eventos;")
        cur.execute(
            """
            CREATE TRIGGER trg_evento_modificado
            BEFORE UPDATE ON eventos
            FOR EACH ROW
            EXECUTE FUNCTION actualizar_evento_modificado();
            """
        )
    conn.commit()


def fetch_pending_traducciones(conn) -> List[int]:
    with conn.cursor() as cur:
        cur.execute(
            """
            SELECT t.id
            FROM traducciones t
            JOIN embeddings e ON e.traduccion_id = t.id
            WHERE t.status = 'done'
              AND t.evento_id IS NULL
              AND t.lang_to = ANY(%s)
            ORDER BY t.id DESC
            LIMIT %s;
            """,
            (EVENT_LANGS, EVENT_BATCH_IDS),
        )
        rows = cur.fetchall()
    return [r[0] for r in rows]


def fetch_embeddings_for(conn, tr_ids: List[int]) -> Dict[int, np.ndarray]:
    if not tr_ids:
        return {}
    with conn.cursor() as cur:
        cur.execute(
            """
            SELECT traduccion_id, vec
            FROM embeddings
            WHERE traduccion_id = ANY(%s);
            """,
            (tr_ids,),
        )
        rows = cur.fetchall()

    out: Dict[int, np.ndarray] = {}
    for tr_id, vec in rows:
        if not vec:
            continue
        arr = np.array([float(x or 0.0) for x in vec], dtype="float32")
        if arr.size == 0:
            continue
        out[int(tr_id)] = arr
    return out


def fetch_centroids(conn) -> List[Dict[str, Any]]:
    with conn.cursor(cursor_factory=psycopg2.extras.DictCursor) as cur:
        cur.execute(
            """
            SELECT id, centroid, total_traducciones
            FROM eventos
            ORDER BY id;
            """
        )
        rows = cur.fetchall()

    centroids: List[Dict[str, Any]] = []
    for r in rows:
        cid = int(r["id"])
        raw = r["centroid"]
        cnt = int(r["total_traducciones"] or 1)
        if not isinstance(raw, (list, tuple)):
            continue
        arr = np.array([float(x or 0.0) for x in raw], dtype="float32")
        if arr.size == 0:
            continue
        centroids.append({"id": cid, "vec": arr, "n": cnt})
    return centroids


def cosine_distance(a: np.ndarray, b: np.ndarray) -> float:
    num = float(np.dot(a, b))
    da = float(np.linalg.norm(a))
    db = float(np.linalg.norm(b))
    denom = da * db
    if denom <= 0.0:
        return 1.0
    cos = num / denom
    if cos > 1.0:
        cos = 1.0
    if cos < -1.0:
        cos = -1.0
    return 1.0 - cos


def assign_to_event(
    conn,
    tr_id: int,
    vec: np.ndarray,
    centroids: List[Dict[str, Any]],
) -> None:
    from psycopg2.extras import Json

    if vec is None or vec.size == 0:
        return

    if not centroids:
        centroid_list = [float(x) for x in vec.tolist()]
        with conn.cursor() as cur:
            cur.execute(
                """
                INSERT INTO eventos (centroid, total_traducciones)
                VALUES (%s, %s)
                RETURNING id;
                """,
                (Json(centroid_list), 1),
            )
            new_id = cur.fetchone()[0]
            cur.execute(
                "UPDATE traducciones SET evento_id = %s WHERE id = %s;",
                (new_id, tr_id),
            )
        centroids.append({"id": new_id, "vec": vec.copy(), "n": 1})
        return

    best_idx: Optional[int] = None
    best_dist: float = 1.0

    for i, c in enumerate(centroids):
        d = cosine_distance(vec, c["vec"])
        if d < best_dist:
            best_dist = d
            best_idx = i

    if best_idx is not None and best_dist <= EVENT_DIST_THRESHOLD:
        c = centroids[best_idx]
        n_old = c["n"]
        new_n = n_old + 1
        new_vec = (c["vec"] * n_old + vec) / float(new_n)

        c["vec"] = new_vec
        c["n"] = new_n

        centroid_list = [float(x) for x in new_vec.tolist()]
        with conn.cursor() as cur:
            cur.execute(
                """
                UPDATE eventos
                SET centroid = %s,
                    total_traducciones = total_traducciones + 1
                WHERE id = %s;
                """,
                (Json(centroid_list), c["id"]),
            )
            cur.execute(
                "UPDATE traducciones SET evento_id = %s WHERE id = %s;",
                (c["id"], tr_id),
            )
        return

    centroid_list = [float(x) for x in vec.tolist()]
    with conn.cursor() as cur:
        cur.execute(
            """
            INSERT INTO eventos (centroid, total_traducciones)
            VALUES (%s, %s)
            RETURNING id;
            """,
            (Json(centroid_list), 1),
        )
        new_id = cur.fetchone()[0]
        cur.execute(
            "UPDATE traducciones SET evento_id = %s WHERE id = %s;",
            (new_id, tr_id),
        )
    centroids.append({"id": new_id, "vec": vec.copy(), "n": 1})


def main():
    log.info(
        "Iniciando cluster_worker eventos "
        "(EVENT_LANGS=%s, BATCH_IDS=%s, DIST_THRESHOLD=%.3f, SLEEP=%.1fs)",
        ",".join(EVENT_LANGS),
        EVENT_BATCH_IDS,
        EVENT_DIST_THRESHOLD,
        EVENT_SLEEP_IDLE,
    )

    while True:
        try:
            with get_conn() as conn:
                ensure_schema(conn)

                pending_ids = fetch_pending_traducciones(conn)
                if not pending_ids:
                    time.sleep(EVENT_SLEEP_IDLE)
                    continue

                log.info("Traducciones pendientes de asignar evento: %d", len(pending_ids))

                emb_by_tr = fetch_embeddings_for(conn, pending_ids)
                if not emb_by_tr:
                    log.warning("No se encontraron embeddings para las traducciones pendientes.")
                    time.sleep(EVENT_SLEEP_IDLE)
                    continue

                centroids = fetch_centroids(conn)
                log.info("Centroides cargados: %d", len(centroids))

                processed = 0
                for tr_id in pending_ids:
                    vec = emb_by_tr.get(tr_id)
                    if vec is None:
                        continue
                    assign_to_event(conn, tr_id, vec, centroids)
                    processed += 1

                conn.commit()
                log.info("Asignación de eventos completada. Traducciones procesadas: %d", processed)

        except Exception as e:
            log.exception("Error en cluster_worker: %s", e)
            time.sleep(EVENT_SLEEP_IDLE)


if __name__ == "__main__":
    main()