"""Axis classifier: correlate per-party PCA positions against ideology reference data
to assign honest, dynamic labels to political compass axes.

Public API: classify_axes(positions_by_window, axes, db_path) -> dict
"""

import logging
from collections import Counter
from pathlib import Path
from typing import Dict, List, Optional, Tuple

import numpy as np
import re
import json

from analysis.svd_labels import get_svd_label, get_fallback_labels

_logger = logging.getLogger(__name__)

# Module-level caches — loaded once per process lifetime.
_ideology_cache: Optional[Dict[str, Dict[str, float]]] = None
_coalition_cache: Optional[Dict[str, set]] = None

# Correlation threshold above which we consider an axis "explained" by a dimension.
_THRESHOLD = 0.65

_LABELS = {
    "lr": "Verzorgingsstaat–Marktwerking",
    "eu": "EU-integratie–Nationalisme",
    "pi": "Populistisch–Institutioneel",
    "co": "Coalitie–Oppositie",
    "pc": "Conservatief–Progressief",
    # When we have no interpretable classifier signal, fall back to the known
    # SVD component meanings rather than generic "As N" labels.
    "fallback_x": get_svd_label(1),
    "fallback_y": get_svd_label(2),
}


# Module-level helper: map internal/modal labels to user-facing labels.
# Remove duplicate lower definition (keep the one at the top)


def display_label_for_modal(modal_label: Optional[str], axis: str) -> str:
    """Return a user-facing axis label for a modal/internal label.

    Maps numeric fallback names 'As 1' / 'Stempatroon As 1' to the
    semantic labels from SVD_THEMES. Any other label is returned unchanged.
    None is treated as the semantic fallback for the axis.
    """
    if modal_label is None:
        # Fallback to component 1 (x) or 2 (y)
        comp = 1 if axis == "x" else 2
        return get_svd_label(comp)

    # Map "As 1" / "As 2" to semantic labels
    if axis == "x" and modal_label in ("As 1", "Stempatroon As 1"):
        return get_svd_label(1)
    if axis == "y" and modal_label in ("As 2", "Stempatroon As 2"):
        return get_svd_label(2)

    return modal_label


_INTERPRETATION_TEMPLATES = {
    "lr": "De {orientation} as weerspiegelt de economische tegenstelling tussen verzorgingsstaat en marktwerking.",
    "eu": "De {orientation} as weerspiegelt de tegenstelling tussen EU-integratie/internationalisme en nationalisme/soevereiniteit.",
    "pi": "De {orientation} as scheidt populistisch-nationalistische partijen van het institutioneel-parlementaire establishment.",
    "co": (
        "De {orientation} as weerspiegelt stemgedrag van coalitie- versus "
        "oppositiepartijen (r={r:.2f}). Ideologische tegenstellingen zijn minder dominant dit jaar."
    ),
    "pc": "De {orientation} as weerspiegelt de progressief-conservatieve tegenstelling.",
}

# Maps motion-path keyword labels to _INTERPRETATION_TEMPLATES keys.
# Labels not present here fall back to "fallback".
_MOTION_LABEL_TEMPLATE_KEY: Dict[str, str] = {
    "Verzorgingsstaat–Marktwerking": "lr",
    "EU-integratie–Nationalisme": "eu",
    "Populistisch–Institutioneel": "pi",
    "Progressief–Conservatief": "pc",
}


# Simple keyword-based classifier for motion titles (fallback signal)
_KEYWORD_THRESHOLD = 0.4

_KEYWORDS: Dict[str, List[str]] = {
    "Verzorgingsstaat–Marktwerking": [
        # economic / welfare state
        "belasting",
        "uitkering",
        "bijstand",
        "minimumloon",
        "cao",
        "vakbond",
        "bezuiniging",
        "privatisering",
        "subsidie",
        "pensioen",
        "aow",
        "zorg",
        "huur",
        "woning",
        "sociaal",
        "werkloos",
        "ww",
        "arbeidsongeschik",
        "wao",
        "gemeentefonds",
    ],
    "EU-integratie–Nationalisme": [
        # EU and international cooperation
        "europees",
        "europese",
        " eu ",
        "eu-",
        "verdrag",
        "intergouvernementeel",
        "samenwerking",
        "internationaal",
        "navo",
        "nato",
        " vn ",
        "vn-",
        "sancties",
        "israël",
        "vluchteling",
        "asiel",
        "soevereiniteit",
        "nationaal",
    ],
    "Populistisch–Institutioneel": [
        # Populist/nationalist themes
        "terugsturen",
        "syrië",
        "syrier",
        "grenzen dicht",
        "remigratie",
        "eigen volk",
        "nederland eerst",
        "corona",
        "vaccin",
        "ivermectine",
        "hydroxychloroquine",
        "complot",
        "deep state",
        "establishment",
        "elite",
        "herstelbetaling",
        "excuses",
    ],
    "Progressief–Conservatief": [
        # environment
        "klimaat",
        "stikstof",
        "duurzaam",
        "duurzaamheid",
        "co2",
        "energietransitie",
        "biodiversiteit",
        # social
        "euthanasie",
        "abortus",
        "lgbtq",
        "transgender",
        "diversiteit",
        "traditi",
        "gezin",
        "religie",
        "geloof",
    ],
}

# Pre-compiled regexes for keyword matching. We escape keywords but do NOT add
# word-boundaries because some keywords intentionally match substrings
# (e.g. 'traditi' matching 'tradities'). re.IGNORECASE makes lowercasing
# unnecessary during matching.
_KEYWORD_REGEXES: Dict[str, "re.Pattern[str]"] = {
    cat: re.compile(
        "|".join(re.escape(kw.strip()) for kw in kws),
        re.IGNORECASE,
    )
    for cat, kws in _KEYWORDS.items()
}


def _classify_from_titles(titles: List[str]) -> Tuple[Optional[str], float]:
    """Classify a list of motion titles into an axis category using keyword matching.

    Returns (category_label, confidence) where confidence = fraction of titles
    containing at least one keyword from the winning category.
    Returns (None, confidence) if confidence is below _KEYWORD_THRESHOLD.
    """
    if not titles:
        return None, 0.0

    counts: Dict[str, int] = {cat: 0 for cat in _KEYWORDS}
    for title in titles:
        for cat, rx in _KEYWORD_REGEXES.items():
            if rx.search(title):
                counts[cat] += 1

    # Determine the best category, but be deterministic on ties: if more than
    # one category has the top count, return None to indicate ambiguity.
    best_count = max(counts.values())
    best_cats = [cat for cat, cnt in counts.items() if cnt == best_count]
    confidence = best_count / len(titles)

    if len(best_cats) != 1 or confidence < _KEYWORD_THRESHOLD:
        return None, confidence

    return best_cats[0], confidence


def _load_motion_vectors(db_path: str, window_id: str) -> Dict[int, np.ndarray]:
    """Load SVD motion vectors for a given window from DuckDB.

    Returns {motion_id: vector_array}. Returns {} on any error.
    """
    try:
        import duckdb

        conn = duckdb.connect(db_path, read_only=True)
        try:
            rows = conn.execute(
                "SELECT entity_id, vector FROM svd_vectors "
                "WHERE entity_type = 'motion' AND window_id = ?",
                [window_id],
            ).fetchall()
        finally:
            conn.close()
        result: Dict[int, np.ndarray] = {}
        for entity_id, vector_raw in rows:
            try:
                mid = int(entity_id)
                vec = np.array(json.loads(vector_raw), dtype=float)
                result[mid] = vec
            except Exception:
                continue
        return result
    except Exception as exc:
        _logger.debug("Failed to load motion vectors for window %s: %s", window_id, exc)
        return {}


def _project_motions(
    motion_vecs: Dict[int, np.ndarray],
    x_axis: np.ndarray,
    y_axis: np.ndarray,
    global_mean: np.ndarray,
) -> Dict[int, Tuple[float, float]]:
    """Project motion vectors onto the PCA axes after centering by global_mean.

    Returns {motion_id: (x_score, y_score)}.
    """
    try:
        projections: Dict[int, Tuple[float, float]] = {}
        for mid, vec in motion_vecs.items():
            try:
                centered = vec - global_mean
                x_score = float(np.dot(centered, x_axis))
                y_score = float(np.dot(centered, y_axis))
                projections[mid] = (x_score, y_score)
            except Exception:
                continue
        return projections
    except Exception as exc:
        _logger.debug("Failed to project motions: %s", exc)
        return {}


def _top_motion_ids(
    projections: Dict[int, Tuple[float, float]],
    axis: str,
    n: int = 5,
) -> Dict[str, List[int]]:
    """Return the top-n motion IDs at each pole of the given axis.

    axis: 'x' or 'y'
    Returns {'+': [motion_ids], '-': [motion_ids]} (highest positive first,
    most negative first in the '-' list).
    """
    try:
        if axis not in ("x", "y"):
            raise ValueError("axis must be 'x' or 'y'")
        idx = 0 if axis == "x" else 1
        sorted_ids = sorted(projections, key=lambda mid: projections[mid][idx])
        neg_ids = sorted_ids[:n]
        pos_ids = sorted_ids[-n:][::-1]
        return {"+": pos_ids, "-": neg_ids}
    except Exception as exc:
        _logger.debug("Failed to compute top_motion_ids: %s", exc)
        return {"+": [], "-": []}


def _fetch_motion_titles(
    db_path: str,
    motion_ids: List[int],
) -> Dict[int, Tuple[str, str]]:
    """Fetch (title, date) for a list of motion IDs from DuckDB.

    Returns {motion_id: (title, date_str)}. Missing IDs are omitted.
    Returns {} on any DB error.
    """
    if not motion_ids:
        return {}
    try:
        import duckdb

        placeholders = ", ".join("?" for _ in motion_ids)
        conn = duckdb.connect(db_path, read_only=True)
        try:
            rows = conn.execute(
                f"SELECT id, title, date FROM motions WHERE id IN ({placeholders})",
                motion_ids,
            ).fetchall()
        finally:
            conn.close()
        return {int(row[0]): (str(row[1]), str(row[2])) for row in rows}
    except Exception as exc:
        _logger.debug("Failed to fetch motion titles: %s", exc)
        return {}


def _load_ideology(csv_path: Path) -> Dict[str, Dict[str, float]]:
    """Load party ideology scores from CSV.

    Returns {party_name: {"left_right": float, "progressive": float}}.
    Returns {} on any error (caller should treat empty as 'skip classification').
    """
    global _ideology_cache
    if _ideology_cache is not None:
        return _ideology_cache
    result: Dict[str, Dict[str, float]] = {}
    try:
        with open(csv_path, encoding="utf-8") as fh:
            lines = fh.read().splitlines()
        header = [h.strip() for h in lines[0].split(",")]
        lr_idx = header.index("left_right")
        pc_idx = header.index("progressive")
        for line in lines[1:]:
            if not line.strip():
                continue
            parts = [p.strip() for p in line.split(",")]
            if len(parts) <= max(lr_idx, pc_idx):
                continue
            result[parts[0]] = {
                "left_right": float(parts[lr_idx]),
                "progressive": float(parts[pc_idx]),
            }
    except FileNotFoundError:
        _logger.warning(
            "party_ideologies.csv not found at %s — axis labels will be generic",
            csv_path,
        )
        return {}
    except Exception as exc:
        _logger.warning("Failed to load party_ideologies.csv: %s", exc)
        return {}
    _ideology_cache = result
    return result


def _load_coalition(csv_path: Path) -> Dict[str, set]:
    """Load coalition membership from CSV.

    Returns {window_id: set_of_party_names}.
    Returns {} on any error (coalition dimension will be skipped).
    """
    global _coalition_cache
    if _coalition_cache is not None:
        return _coalition_cache
    result: Dict[str, set] = {}
    try:
        with open(csv_path, encoding="utf-8") as fh:
            lines = fh.read().splitlines()
        for line in lines[1:]:
            if not line.strip():
                continue
            parts = [p.strip() for p in line.split(",")]
            if len(parts) < 2:
                continue
            wid, party = parts[0], parts[1]
            result.setdefault(wid, set()).add(party)
    except FileNotFoundError:
        _logger.warning(
            "coalition_membership.csv not found at %s — coalition axis detection disabled",
            csv_path,
        )
        return {}
    except Exception as exc:
        _logger.warning("Failed to load coalition_membership.csv: %s", exc)
        return {}
    _coalition_cache = result
    return result


def _window_year(window_id: str) -> Optional[str]:
    """Extract year string from window_id.

    Returns None for 'current_parliament'.
    '2016' → '2016', '2016-Q3' → '2016'.
    """
    if window_id == "current_parliament":
        return None
    return window_id.split("-")[0]


def _pearsonr(x: List[float], y: List[float]) -> float:
    """Pearson r; returns 0.0 for degenerate input (< 3 points or zero variance)."""
    if len(x) < 3:
        return 0.0
    xa = np.array(x, dtype=float)
    ya = np.array(y, dtype=float)
    if xa.std() < 1e-12 or ya.std() < 1e-12:
        return 0.0
    return float(np.corrcoef(xa, ya)[0, 1])


def _assign_label(
    r_lr: float,
    r_co: float,
    r_pc: float,
    axis: str,
) -> Tuple[str, str, float]:
    """Assign label, interpretation and quality score for one axis.

    Priority: left-right > coalition > progressive > fallback.
    Returns (label, interpretation_string, quality_score).
    """
    orientation = "horizontale" if axis == "x" else "verticale"
    _x_fallback, _y_fallback = get_fallback_labels()
    fallback_label = _x_fallback if axis == "x" else _y_fallback
    quality = max(abs(r_lr), abs(r_co), abs(r_pc))

    if abs(r_lr) >= _THRESHOLD:
        return (
            _LABELS["lr"],
            _INTERPRETATION_TEMPLATES["lr"].format(orientation=orientation),
            quality,
        )
    if abs(r_co) >= _THRESHOLD:
        return (
            _LABELS["co"],
            _INTERPRETATION_TEMPLATES["co"].format(orientation=orientation, r=r_co),
            quality,
        )
    if abs(r_pc) >= _THRESHOLD:
        return (
            _LABELS["pc"],
            _INTERPRETATION_TEMPLATES["pc"].format(orientation=orientation),
            quality,
        )
    return (
        fallback_label,
        "",  # No interpretation for unclassified axes
        quality,
    )


def classify_axes(
    positions_by_window: Dict[str, Dict[str, Tuple[float, float]]],
    axes: dict,
    db_path: str,
) -> dict:
    """Classify compass axes using motion projection (primary) and ideology CSV (fallback).

    Motion projection path:
        - Requires axes["global_mean"], axes["x_axis"], axes["y_axis"].
        - Loads motion SVD vectors per window, projects onto PCA axes,
          ranks top 5+5 motions, applies keyword classifier -> label.

    Fallback path (unchanged):
        - Pearson-r against party_ideologies.csv (left_right, progressive).
        - Pearson-r against coalition_membership.csv dummy.

    Enriches axes with:
        x_label, y_label           — global modal label across annual windows
        x_quality, y_quality       — {window_id: float} max |r|
        x_interpretation           — {window_id: str}
        y_interpretation           — {window_id: str}
        x_top_motions, y_top_motions — {window_id: {'+': [(title, date), ...], '-': [...]}}
        x_label_confidence         — {window_id: float}
        y_label_confidence         — {window_id: float}
    """
    data_dir = Path(db_path).parent
    ideology = _load_ideology(data_dir / "party_ideologies.csv")
    coalition = _load_coalition(data_dir / "coalition_membership.csv")

    # Determine whether motion projection is possible.
    global_mean = axes.get("global_mean")
    x_axis_arr = np.array(axes.get("x_axis", []))
    y_axis_arr = np.array(axes.get("y_axis", []))
    motion_path_available = (
        global_mean is not None
        and x_axis_arr.ndim == 1
        and x_axis_arr.size > 0
        and y_axis_arr.size > 0
    )

    # If we have neither ideology reference data nor motion vectors available,
    # there is nothing to classify. Previously an early-exit below could be
    # shadowed by a nested helper definition causing classify_axes to return
    # None. Ensure we return the original axes dict in this case.
    if not ideology and not motion_path_available:
        return axes

    x_quality: Dict[str, float] = {}
    y_quality: Dict[str, float] = {}
    x_interpretation: Dict[str, str] = {}
    y_interpretation: Dict[str, str] = {}
    x_top_motions: Dict[str, Dict] = {}
    y_top_motions: Dict[str, Dict] = {}
    x_label_confidence: Dict[str, float] = {}
    y_label_confidence: Dict[str, float] = {}
    annual_x_labels: List[str] = []
    annual_y_labels: List[str] = []

    for wid, pos_dict in positions_by_window.items():
        year = _window_year(wid)
        is_annual = wid != "current_parliament" and "-" not in wid

        # ── Ideology / coalition Pearson-r (unchanged logic) ──────────────────
        x_lbl_fallback: Optional[str] = None
        y_lbl_fallback: Optional[str] = None
        x_q = 0.0
        y_q = 0.0
        x_int = ""
        y_int = ""

        if ideology:
            parties = [p for p in pos_dict if p in ideology]
            if len(parties) >= 5:
                party_x = [pos_dict[p][0] for p in parties]
                party_y = [pos_dict[p][1] for p in parties]
                ref_lr = [ideology[p]["left_right"] for p in parties]
                ref_pc = [ideology[p]["progressive"] for p in parties]

                if year and coalition and year in coalition:
                    gov_set = coalition[year]
                    ref_co = [1.0 if p in gov_set else -1.0 for p in parties]
                else:
                    ref_co = [0.0] * len(parties)

                r_lr_x = _pearsonr(party_x, ref_lr)
                r_co_x = _pearsonr(party_x, ref_co)
                r_pc_x = _pearsonr(party_x, ref_pc)
                x_lbl_fallback, x_int, x_q = _assign_label(r_lr_x, r_co_x, r_pc_x, "x")

                r_lr_y = _pearsonr(party_y, ref_lr)
                r_co_y = _pearsonr(party_y, ref_co)
                r_pc_y = _pearsonr(party_y, ref_pc)
                y_lbl_fallback, y_int, y_q = _assign_label(r_lr_y, r_co_y, r_pc_y, "y")

        # ── Motion projection (primary) ────────────────────────────────────────
        x_lbl = x_lbl_fallback
        y_lbl = y_lbl_fallback
        x_conf = 0.0
        y_conf = 0.0
        x_tops: Dict[str, List] = {"+": [], "-": []}
        y_tops: Dict[str, List] = {"+": [], "-": []}

        if motion_path_available:
            motion_vecs = _load_motion_vectors(db_path, wid)
            if motion_vecs:
                projections = _project_motions(
                    motion_vecs, x_axis_arr, y_axis_arr, global_mean
                )
                x_ids = _top_motion_ids(projections, "x", n=5)
                y_ids = _top_motion_ids(projections, "y", n=5)

                all_x_ids = x_ids["+"] + x_ids["-"]
                all_y_ids = y_ids["+"] + y_ids["-"]
                titles_map = _fetch_motion_titles(
                    db_path, list(set(all_x_ids + all_y_ids))
                )

                x_title_list = [
                    titles_map[mid][0] for mid in all_x_ids if mid in titles_map
                ]
                y_title_list = [
                    titles_map[mid][0] for mid in all_y_ids if mid in titles_map
                ]

                x_kw_lbl, x_conf = _classify_from_titles(x_title_list)
                y_kw_lbl, y_conf = _classify_from_titles(y_title_list)

                if x_kw_lbl is not None:
                    x_lbl = x_kw_lbl
                    if not x_int:
                        tkey = _MOTION_LABEL_TEMPLATE_KEY.get(x_kw_lbl, "fallback")
                        x_int = _INTERPRETATION_TEMPLATES[tkey].format(
                            orientation="horizontale"
                        )
                if y_kw_lbl is not None:
                    y_lbl = y_kw_lbl
                    if not y_int:
                        tkey = _MOTION_LABEL_TEMPLATE_KEY.get(y_kw_lbl, "fallback")
                        y_int = _INTERPRETATION_TEMPLATES[tkey].format(
                            orientation="verticale"
                        )

                # Build display lists: [(title, date), ...]
                for pole, ids in x_ids.items():
                    x_tops[pole] = [titles_map[mid] for mid in ids if mid in titles_map]
                for pole, ids in y_ids.items():
                    y_tops[pole] = [titles_map[mid] for mid in ids if mid in titles_map]

        # ── Final label resolution ────────────────────────────────────────────
        # If both motion and ideology paths produced nothing, use generic fallback.
        _x_fallback, _y_fallback = get_fallback_labels()
        if x_lbl is None:
            x_lbl = _x_fallback
            x_int = ""  # No interpretation for unclassified axes
        if y_lbl is None:
            y_lbl = _y_fallback
            y_int = ""  # No interpretation for unclassified axes

        x_quality[wid] = x_q
        y_quality[wid] = y_q
        x_interpretation[wid] = x_int
        y_interpretation[wid] = y_int
        x_top_motions[wid] = x_tops
        y_top_motions[wid] = y_tops
        x_label_confidence[wid] = x_conf
        y_label_confidence[wid] = y_conf

        if is_annual:
            annual_x_labels.append(x_lbl)
            annual_y_labels.append(y_lbl)

    def _modal(labels: List[str], fallback: str) -> str:
        if not labels:
            return fallback
        return Counter(labels).most_common(1)[0][0]

    # Use the module-level display_label_for_modal defined above.

    enriched = dict(axes)
    # Resolve modal label across annual windows. If the modal label is the
    # internal generic component name ("As 1"/"As 2" or legacy
    # "Stempatroon As N"), prefer a conventional short semantic fallback so the
    # UI doesn't display unhelpful "As N" strings to end users.
    modal_x = _modal(annual_x_labels, "Links\u2013Rechts")
    modal_y = _modal(annual_y_labels, "Progressief\u2013Conservatief")

    enriched["x_label"] = display_label_for_modal(modal_x, "x")
    enriched["y_label"] = display_label_for_modal(modal_y, "y")
    enriched["x_quality"] = x_quality
    enriched["y_quality"] = y_quality
    enriched["x_interpretation"] = x_interpretation
    enriched["y_interpretation"] = y_interpretation
    enriched["x_top_motions"] = x_top_motions
    enriched["y_top_motions"] = y_top_motions
    enriched["x_label_confidence"] = x_label_confidence
    enriched["y_label_confidence"] = y_label_confidence
    return enriched