"""
Pydantic models for API request/response validation
"""

from typing import Optional, List, Dict, Any, Union
from pydantic import BaseModel, Field, validator
from datetime import datetime
import uuid


class Message(BaseModel):
    """Message model for memory input"""
    role: str = Field(..., description="Message role (user, assistant)")
    content: str = Field(..., description="Message content", min_length=1, max_length=10000)


class AddMemoryRequest(BaseModel):
    """Request model for adding memories"""
    messages: List[Message] = Field(..., description="List of messages to process")
    user_id: str = Field(..., description="User identifier", min_length=1, max_length=100)
    metadata: Optional[Dict[str, Any]] = Field(default={}, description="Additional metadata")

    @validator('user_id')
    def validate_user_id(cls, v):
        if not v.strip():
            raise ValueError('user_id cannot be empty')
        return v.strip()


class SearchMemoriesRequest(BaseModel):
    """Request model for searching memories"""
    query: str = Field(..., description="Search query", min_length=1, max_length=1000)
    user_id: str = Field(..., description="User identifier", min_length=1, max_length=100)
    limit: Optional[int] = Field(default=10, description="Number of results", ge=1, le=100)
    threshold: Optional[float] = Field(default=0.0, description="Similarity threshold", ge=0.0, le=1.0)


class UpdateMemoryRequest(BaseModel):
    """Request model for updating memories"""
    content: Optional[str] = Field(None, description="Updated memory content", max_length=10000)
    metadata: Optional[Dict[str, Any]] = Field(None, description="Updated metadata")


class MemoryResponse(BaseModel):
    """Response model for memory objects"""
    id: str = Field(..., description="Memory identifier")
    memory: str = Field(..., description="Processed memory content")
    user_id: str = Field(..., description="User identifier")
    hash: Optional[str] = Field(None, description="Content hash")
    score: Optional[float] = Field(None, description="Similarity score")
    metadata: Optional[Dict[str, Any]] = Field(default={}, description="Memory metadata")
    created_at: datetime = Field(..., description="Creation timestamp")
    updated_at: Optional[datetime] = Field(None, description="Last update timestamp")


class MemoryAddResult(BaseModel):
    """Result of adding a memory"""
    id: str = Field(..., description="Memory identifier")
    memory: str = Field(..., description="Processed memory content")
    event: str = Field(..., description="Event type (ADD, UPDATE)")
    previous_memory: Optional[str] = Field(None, description="Previous memory content if updated")


class StandardResponse(BaseModel):
    """Standard API response format"""
    success: bool = Field(..., description="Operation success status")
    data: Optional[Union[Dict[str, Any], List[Any]]] = Field(None, description="Response data")
    message: str = Field(..., description="Response message")
    timestamp: datetime = Field(default_factory=datetime.now, description="Response timestamp")
    request_id: str = Field(default_factory=lambda: str(uuid.uuid4()), description="Request identifier")


class ErrorResponse(BaseModel):
    """Error response format"""
    success: bool = Field(default=False, description="Always false for errors")
    error: Dict[str, Any] = Field(..., description="Error details")
    timestamp: datetime = Field(default_factory=datetime.now, description="Error timestamp")


class ErrorDetail(BaseModel):
    """Error detail structure"""
    code: str = Field(..., description="Error code")
    message: str = Field(..., description="Human readable error message")
    details: Optional[Dict[str, Any]] = Field(default={}, description="Additional error details")
    request_id: str = Field(default_factory=lambda: str(uuid.uuid4()), description="Request identifier")


class HealthResponse(BaseModel):
    """Health check response"""
    status: str = Field(..., description="Health status")
    timestamp: datetime = Field(default_factory=datetime.now, description="Check timestamp")
    uptime: Optional[float] = Field(None, description="Server uptime in seconds")


class SystemStatusResponse(BaseModel):
    """System status response"""
    status: str = Field(..., description="Overall system status")
    version: str = Field(..., description="API version")
    mem0_version: str = Field(..., description="mem0 library version")
    services: Dict[str, str] = Field(..., description="Service status")
    database: Dict[str, Any] = Field(..., description="Database status")
    timestamp: datetime = Field(default_factory=datetime.now, description="Status timestamp")


class UserStatsResponse(BaseModel):
    """User statistics response"""
    user_id: str = Field(..., description="User identifier")
    total_memories: int = Field(..., description="Total number of memories")
    recent_memories: int = Field(..., description="Memories added in last 24h")
    oldest_memory: Optional[datetime] = Field(None, description="Oldest memory timestamp")
    newest_memory: Optional[datetime] = Field(None, description="Newest memory timestamp")
    storage_usage: Dict[str, Any] = Field(..., description="Storage usage statistics")


class SearchResultsResponse(BaseModel):
    """Search results response"""
    results: List[MemoryResponse] = Field(..., description="Search results")
    query: str = Field(..., description="Original search query")
    total_results: int = Field(..., description="Total number of results")
    execution_time: float = Field(..., description="Search execution time in seconds")


class DeleteResponse(BaseModel):
    """Delete operation response"""
    deleted: bool = Field(..., description="Deletion success status")
    memory_id: str = Field(..., description="Deleted memory identifier")
    message: str = Field(..., description="Deletion message")


class BulkDeleteResponse(BaseModel):
    """Bulk delete operation response"""
    deleted_count: int = Field(..., description="Number of deleted memories")
    user_id: str = Field(..., description="User identifier")
    message: str = Field(..., description="Bulk deletion message")


class APIMetricsResponse(BaseModel):
    """API metrics response"""
    total_requests: int = Field(..., description="Total API requests")
    requests_per_minute: float = Field(..., description="Average requests per minute")
    average_response_time: float = Field(..., description="Average response time in ms")
    error_rate: float = Field(..., description="Error rate percentage")
    active_users: int = Field(..., description="Active users in last hour")
    top_endpoints: List[Dict[str, Any]] = Field(..., description="Most used endpoints")
    timestamp: datetime = Field(default_factory=datetime.now, description="Metrics timestamp")