"""Interpolation engine — macro-to-company impact scoring.

Computes per-company macro impact scores by evaluating overlap between
global event classifications and company exposure profiles.  Produces
MacroImpactRecord objects that feed into the aggregation engine as
additional weighted signals.

Requirements: 4.1, 4.2, 4.3, 4.4, 4.5, 4.6, 3.2
"""
from __future__ import annotations

import json
import logging
from dataclasses import dataclass, field
from datetime import datetime, timezone

import asyncpg

from services.extractor.event_classifier import GlobalEvent
from services.shared.schemas import (
    ExposureProfileSchema,
    MarketPositionTier,
    SeverityLevel,
)

logger = logging.getLogger("interpolation")

# ---------------------------------------------------------------------------
# Default configuration constants
# ---------------------------------------------------------------------------

DEFAULT_CONFIDENCE_THRESHOLD = 0.4
DEFAULT_SHORT_TERM_STALENESS_HOURS = 48
ACCELERATED_DECAY_MULTIPLIER = 0.5  # applied on top of standard recency decay

# ---------------------------------------------------------------------------
# Constants
# ---------------------------------------------------------------------------

# Severity weights
SEVERITY_WEIGHTS: dict[str, float] = {
    SeverityLevel.CRITICAL.value: 1.0,
    SeverityLevel.HIGH.value: 0.75,
    SeverityLevel.MODERATE.value: 0.5,
    SeverityLevel.LOW.value: 0.25,
}

# Component weights in the scoring formula
GEO_WEIGHT = 0.35
SUPPLY_WEIGHT = 0.25
COMMODITY_WEIGHT = 0.25
SECTOR_WEIGHT = 0.15

# Resilience modifiers for international events
RESILIENCE_MODIFIERS: dict[str, float] = {
    MarketPositionTier.GLOBAL_LEADER.value: 0.7,
    MarketPositionTier.MULTINATIONAL.value: 0.85,
    MarketPositionTier.REGIONAL.value: 1.0,
    MarketPositionTier.DOMESTIC.value: 1.2,
}

# Event types that are typically negative
_NEGATIVE_EVENT_TYPES = frozenset({
    "supply_disruption",
    "cost_increase",
    "regulatory_pressure",
    "geopolitical_risk",
    "trade_barrier",
})

# Event types that can be positive
_POSITIVE_EVENT_TYPES = frozenset({
    "demand_shift",
})

# Event types that can go either way
_AMBIGUOUS_EVENT_TYPES = frozenset({
    "commodity_shock",
    "currency_impact",
})

# Market cap bucket → market position tier mapping for default profiles
_CAP_TO_TIER: dict[str, str] = {
    "large_cap": MarketPositionTier.GLOBAL_LEADER.value,
    "mid_cap": MarketPositionTier.MULTINATIONAL.value,
    "small_cap": MarketPositionTier.REGIONAL.value,
    "micro_cap": MarketPositionTier.DOMESTIC.value,
}

# Sector-based default geographic revenue mixes
_SECTOR_DEFAULT_GEO: dict[str, dict[str, float]] = {
    "Information Technology": {"US": 0.45, "CN": 0.15, "EU": 0.15, "JP": 0.10, "KR": 0.15},
    "Health Care": {"US": 0.50, "EU": 0.25, "JP": 0.10, "CN": 0.15},
    "Financials": {"US": 0.55, "EU": 0.20, "GB": 0.15, "JP": 0.10},
    "Energy": {"US": 0.30, "SA": 0.20, "RU": 0.15, "CA": 0.15, "AE": 0.20},
    "Materials": {"US": 0.25, "CN": 0.25, "AU": 0.20, "BR": 0.15, "IN": 0.15},
    "Industrials": {"US": 0.40, "DE": 0.15, "CN": 0.15, "JP": 0.15, "KR": 0.15},
    "Consumer Discretionary": {"US": 0.45, "CN": 0.20, "EU": 0.15, "JP": 0.10, "IN": 0.10},
    "Consumer Staples": {"US": 0.45, "EU": 0.20, "CN": 0.15, "IN": 0.10, "BR": 0.10},
    "Communication Services": {"US": 0.50, "CN": 0.15, "EU": 0.15, "JP": 0.10, "IN": 0.10},
    "Utilities": {"US": 0.70, "EU": 0.15, "JP": 0.15},
    "Real Estate": {"US": 0.60, "CN": 0.15, "EU": 0.15, "JP": 0.10},
}

_DEFAULT_GEO = {"US": 0.50, "EU": 0.20, "CN": 0.15, "JP": 0.15}


# ---------------------------------------------------------------------------
# MacroImpactRecord dataclass
# ---------------------------------------------------------------------------

@dataclass
class MacroImpactRecord:
    """A computed macro impact score for a specific company-event pair."""

    event_id: str = ""
    company_id: str = ""
    ticker: str = ""
    macro_impact_score: float = 0.0  # [0, 1]
    impact_direction: str = "neutral"  # positive|negative|mixed
    contributing_factors: list[str] = field(default_factory=list)
    confidence: float = 0.5  # [0, 1]
    computed_at: datetime = field(default_factory=lambda: datetime.now(timezone.utc))


# ---------------------------------------------------------------------------
# Overlap computation functions
# ---------------------------------------------------------------------------


def compute_geographic_overlap(
    event_regions: list[str],
    revenue_mix: dict[str, float],
) -> float:
    """Compute geographic overlap using revenue percentage weighting.

    For each event region that appears in the company's revenue mix,
    sum the revenue percentage.  Returns a value in [0, 1].

    Args:
        event_regions: Region codes from the global event.
        revenue_mix: Company's geographic_revenue_mix (region -> pct).

    Returns:
        Sum of revenue percentages for overlapping regions, clamped to [0, 1].
    """
    if not event_regions or not revenue_mix:
        return 0.0

    event_set = {r.upper() for r in event_regions}
    overlap = 0.0
    for region, pct in revenue_mix.items():
        if region.upper() in event_set:
            overlap += pct

    return min(max(overlap, 0.0), 1.0)


def compute_supply_chain_overlap(
    event_regions: list[str],
    supply_regions: list[str],
) -> float:
    """Compute supply chain overlap using set intersection ratio.

    Returns the fraction of the company's supply chain regions that
    overlap with the event's affected regions.

    Args:
        event_regions: Region codes from the global event.
        supply_regions: Company's supply_chain_regions.

    Returns:
        Intersection ratio in [0, 1].  0.0 if supply_regions is empty.
    """
    if not event_regions or not supply_regions:
        return 0.0

    event_set = {r.upper() for r in event_regions}
    supply_set = {r.upper() for r in supply_regions}

    intersection = event_set & supply_set
    return len(intersection) / len(supply_set)


def compute_commodity_overlap(
    event_commodities: list[str],
    company_commodities: list[str],
) -> float:
    """Compute commodity overlap using set intersection ratio.

    Returns the fraction of the company's key commodities that overlap
    with the event's affected commodities.

    Args:
        event_commodities: Commodity identifiers from the global event.
        company_commodities: Company's key_input_commodities.

    Returns:
        Intersection ratio in [0, 1].  0.0 if company_commodities is empty.
    """
    if not event_commodities or not company_commodities:
        return 0.0

    event_set = {c.lower() for c in event_commodities}
    company_set = {c.lower() for c in company_commodities}

    intersection = event_set & company_set
    return len(intersection) / len(company_set)


# ---------------------------------------------------------------------------
# Resilience modifier
# ---------------------------------------------------------------------------


def apply_resilience_modifier(
    raw_score: float,
    tier: str,
    event_is_international: bool = True,
) -> float:
    """Apply a resilience modifier based on market position tier.

    For international events, global leaders get a dampening factor (0.7)
    while domestic companies get an amplification factor (1.2).
    For domestic-only events, no modifier is applied.

    Args:
        raw_score: The raw impact score before resilience adjustment.
        tier: Market position tier value.
        event_is_international: Whether the event affects multiple countries.

    Returns:
        Modified score clamped to [0, 1].
    """
    if not event_is_international:
        return min(max(raw_score, 0.0), 1.0)

    modifier = RESILIENCE_MODIFIERS.get(tier, 1.0)
    return min(max(raw_score * modifier, 0.0), 1.0)


# ---------------------------------------------------------------------------
# Impact direction determination
# ---------------------------------------------------------------------------


def _determine_impact_direction(
    event_types: list[str],
) -> tuple[str, list[str], list[str]]:
    """Determine impact direction from event types.

    Returns:
        Tuple of (direction, positive_factors, negative_factors).
    """
    positive_factors: list[str] = []
    negative_factors: list[str] = []

    for et in event_types:
        if et in _NEGATIVE_EVENT_TYPES:
            negative_factors.append(et)
        elif et in _POSITIVE_EVENT_TYPES:
            positive_factors.append(et)
        elif et in _AMBIGUOUS_EVENT_TYPES:
            # Ambiguous types contribute to both sides
            positive_factors.append(et)
            negative_factors.append(et)

    has_positive = len(positive_factors) > 0
    has_negative = len(negative_factors) > 0

    if has_positive and has_negative:
        return "mixed", positive_factors, negative_factors
    elif has_positive:
        return "positive", positive_factors, negative_factors
    elif has_negative:
        return "negative", positive_factors, negative_factors
    else:
        return "negative", positive_factors, negative_factors


# ---------------------------------------------------------------------------
# Core scoring function
# ---------------------------------------------------------------------------


def compute_macro_impact(
    event: GlobalEvent,
    profile: ExposureProfileSchema,
) -> MacroImpactRecord:
    """Compute the macro impact of a global event on a company.

    Scoring formula:
        raw_score = severity_weight * (
            0.35 * geographic_overlap +
            0.25 * supply_chain_overlap +
            0.25 * commodity_overlap +
            0.15 * sector_match
        )
        final_score = apply_resilience_modifier(raw_score, tier, is_international)

    Args:
        event: The classified global event.
        profile: The company's exposure profile.

    Returns:
        A MacroImpactRecord with the computed score and metadata.
    """
    now = datetime.now(timezone.utc)

    # Compute overlaps
    geo_overlap = compute_geographic_overlap(
        event.affected_regions,
        profile.geographic_revenue_mix,
    )
    supply_overlap = compute_supply_chain_overlap(
        event.affected_regions,
        profile.supply_chain_regions,
    )
    commodity_overlap = compute_commodity_overlap(
        event.affected_commodities,
        profile.key_input_commodities,
    )

    # Sector match: 1.0 if any event sector matches the company's sector
    # We check against the profile's regulatory_jurisdictions as a proxy,
    # but the real sector comes from the company data. For now, we use
    # a simple heuristic: check if any affected_sectors appear in the
    # profile's geographic_revenue_mix keys or supply_chain_regions.
    # The actual sector is not stored in ExposureProfileSchema, so we
    # check if any event sectors match. This will be 0.0 unless the
    # caller provides sector info through contributing_factors.
    sector_match = 0.0
    # We'll compute sector_match based on event sectors — the caller
    # should ensure the profile has relevant sector info. For the
    # default implementation, we always set sector_match to 0.0 here
    # and let the caller override if needed.

    # Check zero-overlap case
    contributing = []
    if geo_overlap > 0:
        contributing.append(f"geographic_overlap:{geo_overlap:.3f}")
    if supply_overlap > 0:
        contributing.append(f"supply_chain_overlap:{supply_overlap:.3f}")
    if commodity_overlap > 0:
        contributing.append(f"commodity_overlap:{commodity_overlap:.3f}")

    total_overlap = geo_overlap + supply_overlap + commodity_overlap + sector_match
    if total_overlap == 0.0:
        return MacroImpactRecord(
            event_id=event.event_id,
            company_id=profile.company_id,
            ticker="",
            macro_impact_score=0.0,
            impact_direction="neutral",
            contributing_factors=[],
            confidence=0.0,
            computed_at=now,
        )

    # Severity weight
    severity_weight = SEVERITY_WEIGHTS.get(event.severity, 0.25)

    # Raw score
    raw_score = severity_weight * (
        GEO_WEIGHT * geo_overlap
        + SUPPLY_WEIGHT * supply_overlap
        + COMMODITY_WEIGHT * commodity_overlap
        + SECTOR_WEIGHT * sector_match
    )

    # Determine if event is international (affects multiple regions)
    is_international = len(event.affected_regions) > 1

    # Apply resilience modifier
    tier = profile.market_position_tier
    if isinstance(tier, MarketPositionTier):
        tier = tier.value
    final_score = apply_resilience_modifier(raw_score, tier, is_international)

    # Determine impact direction
    direction, pos_factors, neg_factors = _determine_impact_direction(event.event_types)

    # Build contributing factors list
    all_factors = list(contributing)
    if pos_factors:
        all_factors.append(f"positive_types:{','.join(pos_factors)}")
    if neg_factors:
        all_factors.append(f"negative_types:{','.join(neg_factors)}")

    # Confidence: combine event confidence with overlap strength
    confidence = min(event.confidence * min(total_overlap + 0.3, 1.0), 1.0)

    return MacroImpactRecord(
        event_id=event.event_id,
        company_id=profile.company_id,
        ticker="",
        macro_impact_score=round(min(final_score, 1.0), 6),
        impact_direction=direction,
        contributing_factors=all_factors,
        confidence=round(confidence, 6),
        computed_at=now,
    )


def compute_macro_impact_with_sector(
    event: GlobalEvent,
    profile: ExposureProfileSchema,
    company_sector: str = "",
) -> MacroImpactRecord:
    """Compute macro impact with explicit sector matching.

    Like compute_macro_impact but accepts a company_sector parameter
    for proper sector_match computation.

    Args:
        event: The classified global event.
        profile: The company's exposure profile.
        company_sector: The company's GICS sector name.

    Returns:
        A MacroImpactRecord with the computed score and metadata.
    """
    now = datetime.now(timezone.utc)

    # Compute overlaps
    geo_overlap = compute_geographic_overlap(
        event.affected_regions,
        profile.geographic_revenue_mix,
    )
    supply_overlap = compute_supply_chain_overlap(
        event.affected_regions,
        profile.supply_chain_regions,
    )
    commodity_overlap = compute_commodity_overlap(
        event.affected_commodities,
        profile.key_input_commodities,
    )

    # Sector match
    sector_match = 0.0
    if company_sector and event.affected_sectors:
        company_sector_lower = company_sector.lower().strip()
        for es in event.affected_sectors:
            if es.lower().strip() == company_sector_lower:
                sector_match = 1.0
                break

    # Contributing factors
    contributing: list[str] = []
    if geo_overlap > 0:
        contributing.append(f"geographic_overlap:{geo_overlap:.3f}")
    if supply_overlap > 0:
        contributing.append(f"supply_chain_overlap:{supply_overlap:.3f}")
    if commodity_overlap > 0:
        contributing.append(f"commodity_overlap:{commodity_overlap:.3f}")
    if sector_match > 0:
        contributing.append(f"sector_match:{company_sector}")

    total_overlap = geo_overlap + supply_overlap + commodity_overlap + sector_match
    if total_overlap == 0.0:
        return MacroImpactRecord(
            event_id=event.event_id,
            company_id=profile.company_id,
            ticker="",
            macro_impact_score=0.0,
            impact_direction="neutral",
            contributing_factors=[],
            confidence=0.0,
            computed_at=now,
        )

    # Severity weight
    severity_weight = SEVERITY_WEIGHTS.get(event.severity, 0.25)

    # Raw score
    raw_score = severity_weight * (
        GEO_WEIGHT * geo_overlap
        + SUPPLY_WEIGHT * supply_overlap
        + COMMODITY_WEIGHT * commodity_overlap
        + SECTOR_WEIGHT * sector_match
    )

    # International check
    is_international = len(event.affected_regions) > 1

    # Resilience modifier
    tier = profile.market_position_tier
    if isinstance(tier, MarketPositionTier):
        tier = tier.value
    final_score = apply_resilience_modifier(raw_score, tier, is_international)

    # Direction
    direction, pos_factors, neg_factors = _determine_impact_direction(event.event_types)

    all_factors = list(contributing)
    if pos_factors:
        all_factors.append(f"positive_types:{','.join(pos_factors)}")
    if neg_factors:
        all_factors.append(f"negative_types:{','.join(neg_factors)}")

    confidence = min(event.confidence * min(total_overlap + 0.3, 1.0), 1.0)

    return MacroImpactRecord(
        event_id=event.event_id,
        company_id=profile.company_id,
        ticker="",
        macro_impact_score=round(min(final_score, 1.0), 6),
        impact_direction=direction,
        contributing_factors=all_factors,
        confidence=round(confidence, 6),
        computed_at=now,
    )


# ---------------------------------------------------------------------------
# Default profile builder
# ---------------------------------------------------------------------------


def build_default_profile(
    sector: str,
    industry: str,
    market_cap_bucket: str,
) -> ExposureProfileSchema:
    """Build a default ExposureProfile for companies without manual profiles.

    Uses sector-based geographic revenue defaults and maps market_cap_bucket
    to market_position_tier:
        large_cap  → global_leader
        mid_cap    → multinational
        small_cap  → regional
        micro_cap  → domestic

    Args:
        sector: GICS sector name.
        industry: Industry name (used for commodity defaults).
        market_cap_bucket: One of large_cap, mid_cap, small_cap, micro_cap.

    Returns:
        An ExposureProfileSchema with source='inferred'.
    """
    tier = _CAP_TO_TIER.get(market_cap_bucket, MarketPositionTier.REGIONAL.value)
    geo_mix = _SECTOR_DEFAULT_GEO.get(sector, _DEFAULT_GEO)

    # Derive supply chain regions from geo mix keys
    supply_regions = list(geo_mix.keys())

    # Derive commodities from sector/industry
    commodities = _infer_commodities(sector, industry)

    # Export dependency based on tier
    export_pct = {
        MarketPositionTier.GLOBAL_LEADER.value: 0.5,
        MarketPositionTier.MULTINATIONAL.value: 0.35,
        MarketPositionTier.REGIONAL.value: 0.15,
        MarketPositionTier.DOMESTIC.value: 0.05,
    }.get(tier, 0.15)

    return ExposureProfileSchema(
        company_id="",
        geographic_revenue_mix=dict(geo_mix),
        supply_chain_regions=supply_regions,
        key_input_commodities=commodities,
        regulatory_jurisdictions=list(geo_mix.keys())[:3],
        market_position_tier=MarketPositionTier(tier),
        export_dependency_pct=export_pct,
        source="inferred",
        confidence=0.5,
        version=1,
    )


def _infer_commodities(sector: str, industry: str) -> list[str]:
    """Infer key input commodities from sector and industry."""
    sector_commodities: dict[str, list[str]] = {
        "Energy": ["crude_oil", "natural_gas"],
        "Materials": ["copper", "steel", "lithium"],
        "Industrials": ["steel", "copper"],
        "Information Technology": ["semiconductors", "lithium"],
        "Consumer Staples": ["wheat", "corn"],
        "Consumer Discretionary": ["steel", "semiconductors"],
        "Health Care": [],
        "Financials": [],
        "Communication Services": [],
        "Utilities": ["natural_gas"],
        "Real Estate": ["steel"],
    }
    return sector_commodities.get(sector, [])


# ---------------------------------------------------------------------------
# PostgreSQL persistence
# ---------------------------------------------------------------------------


async def persist_macro_impact_record(
    pool: asyncpg.Pool,
    record: MacroImpactRecord,
) -> str:
    """Persist a MacroImpactRecord to the macro_impact_records table.

    Returns the row UUID.
    """
    row_id = await pool.fetchval(
        """INSERT INTO macro_impact_records
               (event_id, company_id, ticker, macro_impact_score,
                impact_direction, contributing_factors, confidence, computed_at)
           VALUES ($1::uuid, $2::uuid, $3, $4, $5, $6::jsonb, $7, $8)
           RETURNING id""",
        record.event_id,
        record.company_id,
        record.ticker,
        record.macro_impact_score,
        record.impact_direction,
        json.dumps(record.contributing_factors),
        record.confidence,
        record.computed_at,
    )
    logger.info(
        "Persisted macro impact record for event=%s company=%s score=%.4f direction=%s",
        record.event_id,
        record.company_id,
        record.macro_impact_score,
        record.impact_direction,
    )
    return str(row_id)


async def persist_macro_impact_records(
    pool: asyncpg.Pool,
    records: list[MacroImpactRecord],
) -> list[str]:
    """Persist multiple MacroImpactRecords. Returns list of row UUIDs."""
    ids: list[str] = []
    for record in records:
        if record.macro_impact_score > 0.0:
            row_id = await persist_macro_impact_record(pool, record)
            ids.append(row_id)
    return ids


# ---------------------------------------------------------------------------
# Low-confidence event exclusion (Requirements: 10.1)
# ---------------------------------------------------------------------------


def filter_low_confidence_events(
    events: list[GlobalEvent],
    confidence_threshold: float = DEFAULT_CONFIDENCE_THRESHOLD,
) -> list[GlobalEvent]:
    """Filter out events with confidence below the configurable threshold.

    Events with confidence below the threshold are excluded from macro
    impact computation and the exclusion reason is logged.

    Args:
        events: List of GlobalEvent classifications.
        confidence_threshold: Minimum confidence for inclusion (default 0.4).

    Returns:
        List of events that pass the confidence threshold.

    Requirements: 10.1
    """
    included: list[GlobalEvent] = []
    for event in events:
        if event.confidence < confidence_threshold:
            logger.info(
                "Excluding low-confidence event %s: confidence=%.3f < threshold=%.3f",
                event.event_id,
                event.confidence,
                confidence_threshold,
            )
        else:
            included.append(event)
    return included


# ---------------------------------------------------------------------------
# Accelerated decay for stale short-term events (Requirements: 10.2)
# ---------------------------------------------------------------------------


def compute_standard_recency_decay(
    age_hours: float,
    half_life_hours: float = 168.0,
) -> float:
    """Compute standard exponential recency decay.

    Args:
        age_hours: Age of the event in hours.
        half_life_hours: Half-life for the decay function (default 7 days).

    Returns:
        Decay factor in (0, 1].
    """
    import math
    if age_hours <= 0:
        return 1.0
    return math.exp(-0.693 * age_hours / half_life_hours)


def apply_accelerated_decay(
    age_hours: float,
    estimated_duration: str,
    staleness_hours: float = DEFAULT_SHORT_TERM_STALENESS_HOURS,
    half_life_hours: float = 168.0,
) -> float:
    """Apply accelerated decay for stale short-term events.

    For short_term events older than staleness_hours (default 48h),
    the effective weight is strictly less than standard recency decay.

    For non-short-term events or events within the staleness window,
    standard recency decay is applied.

    Args:
        age_hours: Age of the event in hours.
        estimated_duration: Event's estimated_duration field.
        staleness_hours: Hours after which short-term events get accelerated decay.
        half_life_hours: Half-life for the standard decay function.

    Returns:
        Effective signal weight in (0, 1].

    Requirements: 10.2
    """
    standard_decay = compute_standard_recency_decay(age_hours, half_life_hours)

    if estimated_duration == "short_term" and age_hours > staleness_hours:
        # Apply accelerated decay: multiply standard decay by a factor < 1
        accelerated = standard_decay * ACCELERATED_DECAY_MULTIPLIER
        logger.debug(
            "Accelerated decay for short_term event: age=%.1fh, "
            "standard=%.4f, accelerated=%.4f",
            age_hours, standard_decay, accelerated,
        )
        return accelerated

    return standard_decay