from datetime import datetime
from decimal import Decimal
from typing import Any

from pydantic import BaseModel, Field


class StatsResponse(BaseModel):
    """Comprehensive platform statistics response schema."""

    total_products: int
    unique_brands: int
    unique_categories: int
    unique_marketplaces: int = 0
    unique_vendors: int = 0
    total_inventory_entries: int = 0
    total_inventory_quantity: int = 0


class MarketplaceStatsResponse(BaseModel):
    """Statistics per marketplace response schema."""

    marketplace: str
    total_products: int
    unique_vendors: int
    unique_brands: int


# ============================================================================
# Import Statistics
# ============================================================================


class ImportStatsResponse(BaseModel):
    """Import job statistics response schema.

    Used by: GET /api/v1/admin/marketplace-import-jobs/stats
    """

    total: int = Field(..., description="Total number of import jobs")
    pending: int = Field(..., description="Jobs waiting to start")
    processing: int = Field(..., description="Jobs currently running")
    completed: int = Field(..., description="Successfully completed jobs")
    failed: int = Field(..., description="Failed jobs")
    success_rate: float = Field(..., description="Percentage of successful imports")


# ============================================================================
# User Statistics
# ============================================================================


class UserStatsResponse(BaseModel):
    """User statistics response schema.

    Used by: Platform statistics endpoints
    """

    total_users: int = Field(..., description="Total number of users")
    active_users: int = Field(..., description="Number of active users")
    inactive_users: int = Field(..., description="Number of inactive users")
    admin_users: int = Field(..., description="Number of admin users")
    activation_rate: float = Field(..., description="Percentage of active users")


# ============================================================================
# Vendor Statistics (Admin)
# ============================================================================


class VendorStatsResponse(BaseModel):
    """Vendor statistics response schema for admin dashboard.

    Used by: GET /api/v1/admin/vendors/stats
    """

    total: int = Field(..., description="Total number of vendors")
    verified: int = Field(..., description="Number of verified vendors")
    pending: int = Field(..., description="Number of pending verification vendors")
    inactive: int = Field(..., description="Number of inactive vendors")


# ============================================================================
# Product Statistics
# ============================================================================


class ProductStatsResponse(BaseModel):
    """Product statistics response schema.

    Used by: Platform statistics endpoints
    """

    total_products: int = Field(0, description="Total number of products")
    active_products: int = Field(0, description="Number of active products")
    out_of_stock: int = Field(0, description="Number of out-of-stock products")


# ============================================================================
# Platform Statistics (Combined)
# ============================================================================


class PlatformStatsResponse(BaseModel):
    """Combined platform statistics response schema.

    Used by: GET /api/v1/admin/dashboard/stats/platform
    """

    users: UserStatsResponse
    vendors: VendorStatsResponse
    products: ProductStatsResponse
    orders: "OrderStatsBasicResponse"
    imports: ImportStatsResponse


class OrderStatsBasicResponse(BaseModel):
    """Basic order statistics (stub until Order model is fully implemented).

    Used by: Platform statistics endpoints
    """

    total_orders: int = Field(0, description="Total number of orders")
    pending_orders: int = Field(0, description="Number of pending orders")
    completed_orders: int = Field(0, description="Number of completed orders")


# ============================================================================
# Admin Dashboard Response
# ============================================================================


class AdminDashboardResponse(BaseModel):
    """Admin dashboard response schema.

    Used by: GET /api/v1/admin/dashboard
    """

    platform: dict[str, Any] = Field(..., description="Platform information")
    users: UserStatsResponse
    vendors: VendorStatsResponse
    recent_vendors: list[dict[str, Any]] = Field(
        default_factory=list, description="Recent vendors"
    )
    recent_imports: list[dict[str, Any]] = Field(
        default_factory=list, description="Recent import jobs"
    )


# ============================================================================
# Vendor Dashboard Statistics
# ============================================================================


class VendorProductStats(BaseModel):
    """Vendor product statistics."""

    total: int = Field(0, description="Total products in catalog")
    active: int = Field(0, description="Active products")


class VendorOrderStats(BaseModel):
    """Vendor order statistics."""

    total: int = Field(0, description="Total orders")
    pending: int = Field(0, description="Pending orders")
    completed: int = Field(0, description="Completed orders")


class VendorCustomerStats(BaseModel):
    """Vendor customer statistics."""

    total: int = Field(0, description="Total customers")
    active: int = Field(0, description="Active customers")


class VendorRevenueStats(BaseModel):
    """Vendor revenue statistics."""

    total: float = Field(0, description="Total revenue")
    this_month: float = Field(0, description="Revenue this month")


class VendorInfo(BaseModel):
    """Vendor basic info for dashboard."""

    id: int
    name: str
    vendor_code: str


class VendorDashboardStatsResponse(BaseModel):
    """Vendor dashboard statistics response schema.

    Used by: GET /api/v1/vendor/dashboard/stats
    """

    vendor: VendorInfo
    products: VendorProductStats
    orders: VendorOrderStats
    customers: VendorCustomerStats
    revenue: VendorRevenueStats


# ============================================================================
# Vendor Analytics
# ============================================================================


class VendorAnalyticsImports(BaseModel):
    """Vendor import analytics."""

    count: int = Field(0, description="Number of imports in period")


class VendorAnalyticsCatalog(BaseModel):
    """Vendor catalog analytics."""

    products_added: int = Field(0, description="Products added in period")


class VendorAnalyticsInventory(BaseModel):
    """Vendor inventory analytics."""

    total_locations: int = Field(0, description="Total inventory locations")


class VendorAnalyticsResponse(BaseModel):
    """Vendor analytics response schema.

    Used by: GET /api/v1/vendor/analytics
    """

    period: str = Field(..., description="Analytics period (e.g., '30d')")
    start_date: str = Field(..., description="Period start date")
    imports: VendorAnalyticsImports
    catalog: VendorAnalyticsCatalog
    inventory: VendorAnalyticsInventory


# ============================================================================
# Code Quality Dashboard Statistics
# ============================================================================


class ValidatorStats(BaseModel):
    """Statistics for a single validator type."""

    total_violations: int = 0
    errors: int = 0
    warnings: int = 0
    last_scan: str | None = None


class CodeQualityDashboardStatsResponse(BaseModel):
    """Code quality dashboard statistics response schema.

    Used by: GET /api/v1/admin/code-quality/stats

    Supports multiple validator types: architecture, security, performance.
    When validator_type is specified, returns stats for that type only.
    When not specified, returns combined stats with per-validator breakdown.
    """

    total_violations: int
    errors: int
    warnings: int
    info: int = 0
    open: int
    assigned: int
    resolved: int
    ignored: int
    technical_debt_score: int
    trend: list[dict[str, Any]] = Field(default_factory=list)
    by_severity: dict[str, Any] = Field(default_factory=dict)
    by_rule: dict[str, Any] = Field(default_factory=dict)
    by_module: dict[str, Any] = Field(default_factory=dict)
    top_files: list[dict[str, Any]] = Field(default_factory=list)
    last_scan: str | None = None
    validator_type: str | None = None  # Set when filtering by type
    by_validator: dict[str, ValidatorStats] = Field(
        default_factory=dict,
        description="Per-validator breakdown (architecture, security, performance)",
    )


# ============================================================================
# Customer Statistics (Coming Soon)
# ============================================================================


class CustomerStatsResponse(BaseModel):
    """Schema for customer statistics."""

    customer_id: int
    total_orders: int
    total_spent: Decimal
    average_order_value: Decimal
    last_order_date: datetime | None
    first_order_date: datetime | None
    lifetime_value: Decimal


# ============================================================================
# Order Statistics (Coming Soon)
# ============================================================================


class OrderStatsResponse(BaseModel):
    """Schema for order statistics."""

    total_orders: int
    pending_orders: int
    processing_orders: int
    shipped_orders: int
    delivered_orders: int
    cancelled_orders: int
    total_revenue: Decimal
    average_order_value: Decimal