"""
VQA + Image Search Pipeline - Database Models
==============================================

Pydantic models for MongoDB documents and API schemas.
Following the database-schema-designer skill guidelines.
"""

from pydantic import BaseModel, Field, ConfigDict, model_validator
from typing import List, Optional, Dict, Any
from datetime import datetime, timezone
from uuid import uuid4
from enum import Enum


# =============================================================================
# ENUMS
# =============================================================================

class ImageStatus(str, Enum):
    """Status of image processing."""
    PENDING = "pending"
    PROCESSING = "processing"
    COMPLETED = "completed"
    FAILED = "failed"


# =============================================================================
# EMBEDDED MODELS
# =============================================================================

class BoundingBox(BaseModel):
    """Bounding box coordinates (normalized 0-1)."""
    x_min: float = Field(..., ge=0, le=1, description="Left edge")
    y_min: float = Field(..., ge=0, le=1, description="Top edge")
    x_max: float = Field(..., ge=0, le=1, description="Right edge")
    y_max: float = Field(..., ge=0, le=1, description="Bottom edge")
    
    @model_validator(mode="after")
    def validate_bounds(self) -> "BoundingBox":
        """Ensure min values are less than max values."""
        if self.x_min >= self.x_max:
            raise ValueError(f"x_min ({self.x_min}) must be less than x_max ({self.x_max})")
        if self.y_min >= self.y_max:
            raise ValueError(f"y_min ({self.y_min}) must be less than y_max ({self.y_max})")
        return self


class DetectedObject(BaseModel):
    """An object detected in the image."""
    label: str = Field(..., min_length=1, description="Object label/class")
    confidence: float = Field(..., ge=0, le=1, description="Detection confidence")
    bounding_box: Optional[BoundingBox] = Field(
        default=None, 
        description="Object location in image"
    )


class SceneTag(BaseModel):
    """A scene/environment tag for the image."""
    label: str = Field(..., min_length=1, description="Scene label")
    confidence: float = Field(..., ge=0, le=1, description="Classification confidence")


class ConfidenceScores(BaseModel):
    """Per-field confidence scores for quality tracking."""
    objects: Optional[float] = Field(default=None, ge=0, le=1)
    scene_tags: Optional[float] = Field(default=None, ge=0, le=1)
    caption: Optional[float] = Field(default=None, ge=0, le=1)
    ocr_text: Optional[float] = Field(default=None, ge=0, le=1)
    embedding: Optional[float] = Field(default=None, ge=0, le=1)


# =============================================================================
# MAIN DOCUMENT MODEL (MongoDB)
# =============================================================================

class ImageDocument(BaseModel):
    """
    Image document stored in MongoDB.
    
    This represents the complete perception data extracted from an image.
    The embedding vector is stored separately in Qdrant for efficient similarity search.
    """
    
    # Primary identifiers
    image_id: str = Field(
        default_factory=lambda: str(uuid4()),
        description="Unique image identifier (UUID)"
    )
    source_uri: str = Field(..., description="Original image location (URL or path)")
    user_id: Optional[str] = Field(
        default=None,
        description="Owner user ID (None for legacy/pre-auth images)"
    )
    
    # Perception data
    objects: List[DetectedObject] = Field(
        default_factory=list,
        description="Detected objects with bounding boxes"
    )
    scene_tags: List[SceneTag] = Field(
        default_factory=list,
        description="Scene/environment classification tags"
    )
    caption: Optional[str] = Field(
        default=None,
        description="AI-generated image description"
    )
    ocr_text: Optional[str] = Field(
        default=None,
        description="Extracted text from image (OCR)"
    )
    
    # Quality and versioning
    model_version: str = Field(
        ...,
        description="Perception pipeline version used"
    )
    confidence_scores: ConfidenceScores = Field(
        default_factory=ConfidenceScores,
        description="Per-field confidence metrics"
    )
    status: ImageStatus = Field(
        default=ImageStatus.PENDING,
        description="Processing status"
    )
    error_message: Optional[str] = Field(
        default=None,
        description="Error message if processing failed"
    )
    
    # Timestamps (using timezone-aware UTC)
    created_at: datetime = Field(
        default_factory=lambda: datetime.now(timezone.utc),
        description="Document creation time (UTC)"
    )
    updated_at: datetime = Field(
        default_factory=lambda: datetime.now(timezone.utc),
        description="Last update time (UTC)"
    )
    
    # Additional metadata
    file_size_bytes: Optional[int] = Field(
        default=None,
        ge=0,
        description="Original file size"
    )
    image_width: Optional[int] = Field(default=None, ge=1, description="Image width in pixels")
    image_height: Optional[int] = Field(default=None, ge=1, description="Image height in pixels")
    mime_type: Optional[str] = Field(default=None, description="Image MIME type")
    
    model_config = ConfigDict(
        json_encoders={datetime: lambda v: v.isoformat()}
    )


# =============================================================================
# API REQUEST/RESPONSE MODELS
# =============================================================================

class ImageIngestRequest(BaseModel):
    """Request to ingest a new image."""
    source_uri: Optional[str] = Field(
        default=None,
        description="URL to fetch image from (alternative to file upload)"
    )


class ImageIngestResponse(BaseModel):
    """Response after image ingestion."""
    image_id: str
    status: ImageStatus
    message: str


class TextSearchRequest(BaseModel):
    """Request for text-based image search."""
    query: str = Field(..., min_length=1, description="Search query text")
    limit: int = Field(default=10, ge=1, le=100, description="Max results per page")
    page: int = Field(default=1, ge=1, description="Page number (1-indexed)")
    min_confidence: Optional[float] = Field(
        default=None, 
        ge=0, le=1,
        description="Minimum confidence threshold"
    )
    filters: Optional[Dict[str, Any]] = Field(
        default=None,
        description="Additional filters (e.g., scene_tags, objects)"
    )


class ImageSearchRequest(BaseModel):
    """Request for image similarity search."""
    limit: int = Field(default=10, ge=1, le=100, description="Max results")
    min_similarity: Optional[float] = Field(
        default=None,
        ge=0, le=1,
        description="Minimum similarity score"
    )


class SearchResult(BaseModel):
    """Single search result."""
    image_id: str
    source_uri: str
    score: float = Field(..., ge=0, le=1.01, description="Relevance/similarity score (0-1)")
    caption: Optional[str] = None
    objects: List[str] = Field(default_factory=list, description="Object labels")
    scene_tags: List[str] = Field(default_factory=list, description="Scene labels")


class PaginationInfo(BaseModel):
    """Pagination metadata (shared between list and search endpoints)."""
    page: int
    limit: int
    total: int
    total_pages: int
    has_next: bool
    has_prev: bool


class SearchResponse(BaseModel):
    """Search results response."""
    query: str
    results: List[SearchResult]
    total_count: int
    search_time_ms: float
    pagination: Optional[PaginationInfo] = None


class VQARequest(BaseModel):
    """Request to ask a question about an image."""
    question: str = Field(..., min_length=1, description="Question about the image")
    use_stored_context: bool = Field(
        default=True,
        description="Include stored perception data as context"
    )


class VQAResponse(BaseModel):
    """VQA response."""
    image_id: str
    question: str
    answer: str
    confidence: Optional[float] = Field(
        default=None,
        description="Answer confidence score"
    )
    processing_time_ms: float


class QueryRequest(BaseModel):
    """Unified query request (routed to search or VQA)."""
    query: str = Field(..., min_length=1, description="Natural language query")
    image_id: Optional[str] = Field(
        default=None,
        description="Specific image ID for VQA"
    )


class QueryResponse(BaseModel):
    """Unified query response."""
    query_type: str = Field(..., description="'search' or 'vqa'")
    search_results: Optional[List[SearchResult]] = None
    vqa_answer: Optional[str] = None
    processing_time_ms: float


# =============================================================================
# USER / AUTH MODELS
# =============================================================================

class UserDocument(BaseModel):
    """User document stored in MongoDB."""
    user_id: str = Field(
        default_factory=lambda: str(uuid4()),
        description="Unique user identifier (UUID)"
    )
    email: str = Field(..., description="User email (unique)")
    hashed_password: str = Field(..., description="bcrypt hashed password")
    is_admin: bool = Field(default=False, description="Admin flag")
    created_at: datetime = Field(
        default_factory=lambda: datetime.now(timezone.utc),
    )

    model_config = ConfigDict(
        json_encoders={datetime: lambda v: v.isoformat()}
    )


class RegisterRequest(BaseModel):
    """User registration request."""
    email: str = Field(..., min_length=3, description="Email address")
    password: str = Field(..., min_length=6, description="Password (min 6 chars)")


class LoginRequest(BaseModel):
    """User login request."""
    email: str = Field(..., description="Email address")
    password: str = Field(..., description="Password")


class RefreshRequest(BaseModel):
    """Token refresh request."""
    refresh_token: str = Field(..., description="Refresh token")


class TokenResponse(BaseModel):
    """JWT token pair response."""
    access_token: str
    refresh_token: str
    token_type: str = "bearer"
    expires_in: int = Field(description="Access token lifetime in seconds")


class UserResponse(BaseModel):
    """Public user profile."""
    user_id: str
    email: str
    is_admin: bool
    created_at: datetime