from __future__ import annotations

import enum
from datetime import date, datetime
from typing import Any

import math

from pydantic import BaseModel, Field, field_validator, model_validator
from shapely.geometry import box as shapely_box
from pyproj import Geod


def _sanitize_float(v: Any) -> Any:
    """Replace NaN/inf float values with 0.0 for JSON compatibility."""
    if isinstance(v, float) and (math.isnan(v) or math.isinf(v)):
        return 0.0
    return v


def sanitize_for_json(obj: Any) -> Any:
    """Recursively sanitize a data structure, replacing NaN/inf with 0.0."""
    if isinstance(obj, float):
        return _sanitize_float(obj)
    if isinstance(obj, dict):
        return {k: sanitize_for_json(v) for k, v in obj.items()}
    if isinstance(obj, list):
        return [sanitize_for_json(v) for v in obj]
    return obj

# --- East Africa bounding box (approximate) ---
EA_BOUNDS = (22.0, -5.0, 52.0, 23.0)  # (min_lon, min_lat, max_lon, max_lat)
MAX_LOOKBACK_DAYS = 3 * 365 + 1  # ~3 years


class StatusLevel(str, enum.Enum):
    GREEN = "green"
    AMBER = "amber"
    RED = "red"


class TrendDirection(str, enum.Enum):
    IMPROVING = "improving"
    STABLE = "stable"
    DETERIORATING = "deteriorating"


class ConfidenceLevel(str, enum.Enum):
    HIGH = "high"
    MODERATE = "moderate"
    LOW = "low"


class JobStatus(str, enum.Enum):
    QUEUED = "queued"
    PROCESSING = "processing"
    COMPLETE = "complete"
    FAILED = "failed"


class AOI(BaseModel):
    name: str
    bbox: list[float] = Field(min_length=4, max_length=4)

    @property
    def area_km2(self) -> float:
        geod = Geod(ellps="WGS84")
        poly = shapely_box(*self.bbox)
        area_m2, _ = geod.geometry_area_perimeter(poly)
        return abs(area_m2) / 1e6

    @model_validator(mode="after")
    def validate_geography(self) -> AOI:
        min_lon, min_lat, max_lon, max_lat = self.bbox
        ea_min_lon, ea_min_lat, ea_max_lon, ea_max_lat = EA_BOUNDS
        # Check area first so "too large" error takes priority
        from app.config import MAX_AOI_KM2
        if self.area_km2 > MAX_AOI_KM2:
            raise ValueError(
                f"AOI area ({self.area_km2:.0f} km²) exceeds {MAX_AOI_KM2:,} km² limit"
            )
        if (
            max_lon < ea_min_lon
            or min_lon > ea_max_lon
            or max_lat < ea_min_lat
            or min_lat > ea_max_lat
        ):
            raise ValueError(
                "AOI must intersect the East Africa region "
                f"({ea_min_lon}–{ea_max_lon}°E, {ea_min_lat}–{ea_max_lat}°N)"
            )
        return self


class TimeRange(BaseModel):
    start: date = Field(default=None)
    end: date = Field(default=None)

    @model_validator(mode="after")
    def set_defaults_and_validate(self) -> TimeRange:
        today = date.today()
        if self.end is None:
            self.end = today
        if self.start is None:
            self.start = date(today.year - 1, today.month, today.day)
        if (self.end - self.start).days > MAX_LOOKBACK_DAYS:
            raise ValueError("Time range cannot exceed 3 years")
        return self


class JobRequest(BaseModel):
    aoi: AOI
    time_range: TimeRange = Field(default_factory=TimeRange)
    product_ids: list[str]
    email: str

    @model_validator(mode="before")
    @classmethod
    def _accept_legacy_field_names(cls, data):
        """Accept old 'indicator_ids' field name from stored database records."""
        if isinstance(data, dict):
            if "indicator_ids" in data and "product_ids" not in data:
                data["product_ids"] = data.pop("indicator_ids")
        return data
    season_start: int = Field(default=1, ge=1, le=12)
    season_end: int = Field(default=12, ge=1, le=12)

    def season_months(self) -> list[int]:
        """Return ordered list of month numbers in the analysis season.

        Supports year-boundary wrapping: season_start=10, season_end=3
        yields [10, 11, 12, 1, 2, 3].
        """
        if self.season_start <= self.season_end:
            return list(range(self.season_start, self.season_end + 1))
        else:
            return list(range(self.season_start, 13)) + list(range(1, self.season_end + 1))

    @field_validator("product_ids")
    @classmethod
    def require_at_least_one_product(cls, v: list[str]) -> list[str]:
        if len(v) == 0:
            raise ValueError("At least one EO product must be selected")
        return v


class ProductResult(BaseModel):
    product_id: str
    headline: str

    @model_validator(mode="before")
    @classmethod
    def _accept_legacy_and_sanitize(cls, data):
        """Accept old field names and sanitize NaN/inf floats."""
        if isinstance(data, dict):
            if "indicator_id" in data and "product_id" not in data:
                data["product_id"] = data.pop("indicator_id")
            # Sanitize all float values to prevent JSON serialization errors
            return sanitize_for_json(data)
        return data
    status: StatusLevel
    trend: TrendDirection
    confidence: ConfidenceLevel
    map_layer_path: str
    chart_data: dict[str, Any]
    summary: str
    methodology: str
    limitations: list[str]
    data_source: str = "satellite"
    anomaly_months: int = 0
    z_score_current: float = 0.0
    hotspot_pct: float = 0.0
    confidence_factors: dict[str, float] = Field(default_factory=dict)


class Job(BaseModel):
    id: str
    request: JobRequest
    status: JobStatus = JobStatus.QUEUED
    created_at: datetime = Field(default_factory=datetime.utcnow)
    updated_at: datetime = Field(default_factory=datetime.utcnow)
    progress: dict[str, str] = Field(default_factory=dict)
    results: list[ProductResult] = Field(default_factory=list)
    error: str | None = None


class ProductMeta(BaseModel):
    id: str
    name: str
    category: str
    question: str
    estimated_minutes: int


class AoiAdviceRequest(BaseModel):
    bbox: list[float] = Field(min_length=4, max_length=4)


class CompoundSignal(BaseModel):
    name: str
    triggered: bool
    confidence: str  # "strong", "moderate", "weak"
    description: str
    indicators: list[str]
    overlap_pct: float = 0.0
    affected_ha: float = 0.0