import os

from fastapi import APIRouter, Depends, HTTPException, Query
import logging
from typing import Optional

from ..db_engine import model_to_dict
from ..dependencies import oauth2_scheme, valid_token
from ..services.refractor_init import initialize_card_refractor, _determine_card_type

logger = logging.getLogger(__name__)

router = APIRouter(prefix="/api/v2/refractor", tags=["refractor"])

# Tier -> threshold attribute name.  Index = current_tier; value is the
# attribute on RefractorTrack whose value is the *next* threshold to reach.
# Tier 4 is fully evolved so there is no next threshold (None sentinel).
_NEXT_THRESHOLD_ATTR = {
    0: "t1_threshold",
    1: "t2_threshold",
    2: "t3_threshold",
    3: "t4_threshold",
    4: None,
}


def _build_card_state_response(state, player_name=None) -> dict:
    """Serialise a RefractorCardState into the standard API response shape.

    Produces a flat dict with player_id and team_id as plain integers,
    a nested 'track' dict with all threshold fields, and computed fields:
      - 'next_threshold': threshold for the tier immediately above (None when fully evolved).
      - 'progress_pct': current_value / next_threshold * 100, rounded to 1 decimal
        (None when fully evolved or next_threshold is zero).
      - 'player_name': included when passed (e.g. from a list join); omitted otherwise.

    Uses model_to_dict(recurse=False) internally so FK fields are returned
    as IDs rather than nested objects, then promotes the needed IDs up to
    the top level.
    """
    track = state.track
    track_dict = model_to_dict(track, recurse=False)

    next_attr = _NEXT_THRESHOLD_ATTR.get(state.current_tier)
    next_threshold = getattr(track, next_attr) if next_attr else None

    progress_pct = None
    if next_threshold is not None and next_threshold > 0:
        progress_pct = round((state.current_value / next_threshold) * 100, 1)

    result = {
        "player_id": state.player_id,
        "team_id": state.team_id,
        "current_tier": state.current_tier,
        "current_value": state.current_value,
        "fully_evolved": state.fully_evolved,
        "last_evaluated_at": (
            state.last_evaluated_at.isoformat()
            if hasattr(state.last_evaluated_at, "isoformat")
            else state.last_evaluated_at or None
        ),
        "track": track_dict,
        "next_threshold": next_threshold,
        "progress_pct": progress_pct,
    }

    if player_name is not None:
        result["player_name"] = player_name

    return result


@router.get("/tracks")
async def list_tracks(
    card_type: Optional[str] = Query(default=None),
    token: str = Depends(oauth2_scheme),
):
    if not valid_token(token):
        logging.warning("Bad Token: [REDACTED]")
        raise HTTPException(status_code=401, detail="Unauthorized")

    from ..db_engine import RefractorTrack

    query = RefractorTrack.select()
    if card_type is not None:
        query = query.where(RefractorTrack.card_type == card_type)

    items = [model_to_dict(t, recurse=False) for t in query]
    return {"count": len(items), "items": items}


@router.get("/tracks/{track_id}")
async def get_track(track_id: int, token: str = Depends(oauth2_scheme)):
    if not valid_token(token):
        logging.warning("Bad Token: [REDACTED]")
        raise HTTPException(status_code=401, detail="Unauthorized")

    from ..db_engine import RefractorTrack

    try:
        track = RefractorTrack.get_by_id(track_id)
    except Exception:
        raise HTTPException(status_code=404, detail=f"Track {track_id} not found")

    return model_to_dict(track, recurse=False)


@router.get("/cards")
async def list_card_states(
    team_id: int = Query(...),
    card_type: Optional[str] = Query(default=None),
    tier: Optional[int] = Query(default=None, ge=0, le=4),
    season: Optional[int] = Query(default=None),
    progress: Optional[str] = Query(default=None),
    evaluated_only: bool = Query(default=True),
    limit: int = Query(default=10, ge=1, le=100),
    offset: int = Query(default=0, ge=0),
    token: str = Depends(oauth2_scheme),
):
    """List RefractorCardState rows for a team, with optional filters and pagination.

    Required:
      team_id        -- filter to this team's cards; returns empty list if team has no states

    Optional filters:
      card_type      -- one of 'batter', 'sp', 'rp'; filters by RefractorTrack.card_type
      tier           -- filter by current_tier (0-4)
      season         -- filter to players who have batting or pitching season stats in that
                        season (EXISTS subquery against batting/pitching_season_stats)
      progress       -- 'close' = only cards within 80% of their next tier threshold;
                        fully evolved cards are always excluded from this filter
      evaluated_only -- default True; when True, excludes cards where last_evaluated_at
                        is NULL (cards created but never run through the evaluator).
                        Set to False to include all rows, including zero-value placeholders.

    Pagination:
      limit     -- page size (1-100, default 10)
      offset    -- items to skip (default 0)

    Response: {"count": N, "items": [...]}
      count is the total matching rows before limit/offset.
      Each item includes player_name and progress_pct in addition to the
      standard single-card response fields.

    Sort order: current_tier DESC, current_value DESC.
    """
    if not valid_token(token):
        logging.warning("Bad Token: [REDACTED]")
        raise HTTPException(status_code=401, detail="Unauthorized")

    from ..db_engine import (
        RefractorCardState,
        RefractorTrack,
        Player,
        BattingSeasonStats,
        PitchingSeasonStats,
        fn,
        Case,
        JOIN,
    )

    query = (
        RefractorCardState.select(RefractorCardState, RefractorTrack, Player)
        .join(RefractorTrack)
        .switch(RefractorCardState)
        .join(
            Player, JOIN.LEFT_OUTER, on=(RefractorCardState.player == Player.player_id)
        )
        .where(RefractorCardState.team == team_id)
        .order_by(
            RefractorCardState.current_tier.desc(),
            RefractorCardState.current_value.desc(),
        )
    )

    if card_type is not None:
        query = query.where(RefractorTrack.card_type == card_type)

    if tier is not None:
        query = query.where(RefractorCardState.current_tier == tier)

    if season is not None:
        batter_exists = BattingSeasonStats.select().where(
            (BattingSeasonStats.player == RefractorCardState.player)
            & (BattingSeasonStats.team == RefractorCardState.team)
            & (BattingSeasonStats.season == season)
        )
        pitcher_exists = PitchingSeasonStats.select().where(
            (PitchingSeasonStats.player == RefractorCardState.player)
            & (PitchingSeasonStats.team == RefractorCardState.team)
            & (PitchingSeasonStats.season == season)
        )
        query = query.where(fn.EXISTS(batter_exists) | fn.EXISTS(pitcher_exists))

    if progress == "close":
        next_threshold_expr = Case(
            RefractorCardState.current_tier,
            (
                (0, RefractorTrack.t1_threshold),
                (1, RefractorTrack.t2_threshold),
                (2, RefractorTrack.t3_threshold),
                (3, RefractorTrack.t4_threshold),
            ),
            None,
        )
        query = query.where(
            (RefractorCardState.fully_evolved == False)  # noqa: E712
            & (RefractorCardState.current_value >= next_threshold_expr * 0.8)
        )

    if evaluated_only:
        query = query.where(RefractorCardState.last_evaluated_at.is_null(False))

    total = query.count()
    items = []
    for state in query.offset(offset).limit(limit):
        player_name = None
        try:
            player_name = state.player.p_name
        except Exception:
            pass
        items.append(_build_card_state_response(state, player_name=player_name))

    return {"count": total, "items": items}


@router.get("/cards/{card_id}")
async def get_card_state(card_id: int, token: str = Depends(oauth2_scheme)):
    """Return the RefractorCardState for a card identified by its Card.id.

    Resolves card_id -> (player_id, team_id) via the Card table, then looks
    up the matching RefractorCardState row.  Because duplicate cards for the
    same player+team share one state row (unique-(player,team) constraint),
    any card_id belonging to that player on that team returns the same state.

    Returns 404 when:
      - The card_id does not exist in the Card table.
      - The card exists but has no corresponding RefractorCardState yet.
    """
    if not valid_token(token):
        logging.warning("Bad Token: [REDACTED]")
        raise HTTPException(status_code=401, detail="Unauthorized")

    from ..db_engine import Card, RefractorCardState, RefractorTrack, DoesNotExist

    # Resolve card_id to player+team
    try:
        card = Card.get_by_id(card_id)
    except DoesNotExist:
        raise HTTPException(status_code=404, detail=f"Card {card_id} not found")

    # Look up the refractor state for this (player, team) pair, joining the
    # track so a single query resolves both rows.
    try:
        state = (
            RefractorCardState.select(RefractorCardState, RefractorTrack)
            .join(RefractorTrack)
            .where(
                (RefractorCardState.player == card.player_id)
                & (RefractorCardState.team == card.team_id)
            )
            .get()
        )
    except DoesNotExist:
        raise HTTPException(
            status_code=404,
            detail=f"No refractor state for card {card_id}",
        )

    return _build_card_state_response(state)


@router.post("/cards/{card_id}/evaluate")
async def evaluate_card(card_id: int, token: str = Depends(oauth2_scheme)):
    """Force-recalculate refractor state for a card from career stats.

    Resolves card_id to (player_id, team_id), then recomputes the refractor
    tier from all player_season_stats rows for that pair.  Idempotent.
    """
    if not valid_token(token):
        logging.warning("Bad Token: [REDACTED]")
        raise HTTPException(status_code=401, detail="Unauthorized")

    from ..db_engine import Card
    from ..services.refractor_evaluator import evaluate_card as _evaluate

    try:
        card = Card.get_by_id(card_id)
    except Exception:
        raise HTTPException(status_code=404, detail=f"Card {card_id} not found")

    try:
        result = _evaluate(card.player_id, card.team_id)
    except ValueError as exc:
        raise HTTPException(status_code=404, detail=str(exc))

    return result


@router.post("/evaluate-game/{game_id}")
async def evaluate_game(game_id: int, token: str = Depends(oauth2_scheme)):
    """Evaluate refractor state for all players who appeared in a game.

    Finds all unique (player_id, team_id) pairs from the game's StratPlay rows,
    then for each pair that has a RefractorCardState, re-computes the refractor
    tier. Pairs without a state row are auto-initialized on-the-fly via
    initialize_card_refractor (idempotent). Per-player errors are logged but
    do not abort the batch.
    """
    if not valid_token(token):
        logging.warning("Bad Token: [REDACTED]")
        raise HTTPException(status_code=401, detail="Unauthorized")

    from ..db_engine import RefractorCardState, Player, StratPlay
    from ..services.refractor_boost import apply_tier_boost
    from ..services.refractor_evaluator import evaluate_card

    plays = list(StratPlay.select().where(StratPlay.game == game_id))

    pairs: set[tuple[int, int]] = set()
    for play in plays:
        if play.batter_id is not None:
            pairs.add((play.batter_id, play.batter_team_id))
        if play.pitcher_id is not None:
            pairs.add((play.pitcher_id, play.pitcher_team_id))

    evaluated = 0
    tier_ups = []

    boost_enabled = os.environ.get("REFRACTOR_BOOST_ENABLED", "true").lower() != "false"

    for player_id, team_id in pairs:
        try:
            state = RefractorCardState.get_or_none(
                (RefractorCardState.player_id == player_id)
                & (RefractorCardState.team_id == team_id)
            )
            if state is None:
                try:
                    player = Player.get_by_id(player_id)
                    card_type = _determine_card_type(player)
                    state = initialize_card_refractor(player_id, team_id, card_type)
                except Exception:
                    logger.warning(
                        f"Refractor auto-init failed for player={player_id} "
                        f"team={team_id} — skipping"
                    )
                if state is None:
                    continue

            old_tier = state.current_tier
            # Use dry_run=True so that current_tier is NOT written here.
            # apply_tier_boost() writes current_tier + variant atomically on
            # tier-up.  If no tier-up occurs, apply_tier_boost is not called
            # and the tier stays at old_tier (correct behaviour).
            result = evaluate_card(player_id, team_id, dry_run=True)
            evaluated += 1

            # Use computed_tier (what the formula says) to detect tier-ups.
            computed_tier = result.get("computed_tier", old_tier)
            if computed_tier > old_tier:
                player_name = "Unknown"
                try:
                    p = Player.get_by_id(player_id)
                    player_name = p.p_name
                except Exception:
                    pass

                # Phase 2: Apply rating boosts for each tier gained.
                # apply_tier_boost() writes current_tier + variant atomically.
                # If it fails, current_tier stays at old_tier — automatic retry next game.
                boost_result = None
                if not boost_enabled:
                    # Boost disabled via REFRACTOR_BOOST_ENABLED=false.
                    # Skip notification — current_tier was not written (dry_run),
                    # so reporting a tier-up would be a false notification.
                    continue

                card_type = state.track.card_type if state.track else None
                if card_type:
                    last_successful_tier = old_tier
                    failing_tier = old_tier + 1
                    try:
                        for tier in range(old_tier + 1, computed_tier + 1):
                            failing_tier = tier
                            boost_result = apply_tier_boost(
                                player_id, team_id, tier, card_type
                            )
                            last_successful_tier = tier
                    except Exception as boost_exc:
                        logger.warning(
                            f"Refractor boost failed for player={player_id} "
                            f"team={team_id} tier={failing_tier}: {boost_exc}"
                        )
                        # Report only the tiers that actually succeeded.
                        # If none succeeded, skip the tier_up notification entirely.
                        if last_successful_tier == old_tier:
                            continue
                        # At least one intermediate tier was committed; report that.
                        computed_tier = last_successful_tier
                else:
                    # No card_type means no track — skip boost and skip notification.
                    # A false tier-up notification must not be sent when the boost
                    # was never applied (current_tier was never written to DB).
                    logger.warning(
                        f"Refractor boost skipped for player={player_id} "
                        f"team={team_id}: no card_type on track"
                    )
                    continue

                tier_up_entry = {
                    "player_id": player_id,
                    "team_id": team_id,
                    "player_name": player_name,
                    "old_tier": old_tier,
                    "new_tier": computed_tier,
                    "current_value": result.get("current_value", 0),
                    "track_name": state.track.name if state.track else "Unknown",
                }

                # Non-breaking addition: include boost info when available.
                if boost_result:
                    tier_up_entry["variant_created"] = boost_result.get(
                        "variant_created"
                    )

                tier_ups.append(tier_up_entry)

        except Exception as exc:
            logger.warning(
                f"Refractor eval failed for player={player_id} team={team_id}: {exc}"
            )

    return {"evaluated": evaluated, "tier_ups": tier_ups}