# app/services/letzshop/client_service.py
"""
GraphQL client for Letzshop marketplace API.

Handles authentication, request formatting, and error handling
for all Letzshop API operations.
"""

import logging
import time
from typing import Any

import requests

logger = logging.getLogger(__name__)

# Default API endpoint
DEFAULT_ENDPOINT = "https://letzshop.lu/graphql"


class LetzshopClientError(Exception):
    """Base exception for Letzshop client errors."""

    def __init__(self, message: str, response_data: dict | None = None):
        super().__init__(message)
        self.message = message
        self.response_data = response_data


class LetzshopAuthError(LetzshopClientError):
    """Raised when authentication fails."""


class LetzshopAPIError(LetzshopClientError):
    """Raised when the API returns an error response."""


class LetzshopConnectionError(LetzshopClientError):
    """Raised when connection to the API fails."""


# ============================================================================
# GraphQL Queries
# ============================================================================

QUERY_SHIPMENTS = """
query GetShipments($state: ShipmentState) {
    shipments(state: $state) {
        nodes {
            id
            number
            state
            createdAt
            updatedAt
            order {
                id
                number
                email
                totalPrice {
                    amount
                    currency
                }
                lineItems {
                    nodes {
                        id
                        name
                        quantity
                        price {
                            amount
                            currency
                        }
                    }
                }
                shippingAddress {
                    firstName
                    lastName
                    company
                    address1
                    address2
                    city
                    zip
                    country
                }
                billingAddress {
                    firstName
                    lastName
                    company
                    address1
                    address2
                    city
                    zip
                    country
                }
            }
            inventoryUnits {
                nodes {
                    id
                    state
                    variant {
                        id
                        sku
                        name
                    }
                }
            }
            tracking {
                code
                provider
            }
        }
        pageInfo {
            hasNextPage
            endCursor
        }
    }
}
"""

QUERY_SHIPMENT_BY_ID = """
query GetShipment($id: ID!) {
    node(id: $id) {
        ... on Shipment {
            id
            number
            state
            createdAt
            updatedAt
            order {
                id
                number
                email
                totalPrice {
                    amount
                    currency
                }
            }
            inventoryUnits {
                nodes {
                    id
                    state
                    variant {
                        id
                        sku
                        name
                    }
                }
            }
            tracking {
                code
                provider
            }
        }
    }
}
"""

# ============================================================================
# GraphQL Mutations
# ============================================================================

MUTATION_CONFIRM_INVENTORY_UNITS = """
mutation ConfirmInventoryUnits($input: ConfirmInventoryUnitsInput!) {
    confirmInventoryUnits(input: $input) {
        inventoryUnits {
            id
            state
        }
        errors {
            id
            code
            message
        }
    }
}
"""

MUTATION_REJECT_INVENTORY_UNITS = """
mutation RejectInventoryUnits($input: RejectInventoryUnitsInput!) {
    returnInventoryUnits(input: $input) {
        inventoryUnits {
            id
            state
        }
        errors {
            id
            code
            message
        }
    }
}
"""

MUTATION_SET_SHIPMENT_TRACKING = """
mutation SetShipmentTracking($input: SetShipmentTrackingInput!) {
    setShipmentTracking(input: $input) {
        shipment {
            id
            tracking {
                code
                provider
            }
        }
        errors {
            code
            message
        }
    }
}
"""


class LetzshopClient:
    """
    GraphQL client for Letzshop marketplace API.

    Usage:
        client = LetzshopClient(api_key="your-api-key")
        shipments = client.get_shipments(state="unconfirmed")
    """

    def __init__(
        self,
        api_key: str,
        endpoint: str = DEFAULT_ENDPOINT,
        timeout: int = 30,
    ):
        """
        Initialize the Letzshop client.

        Args:
            api_key: The Letzshop API key (Bearer token).
            endpoint: The GraphQL endpoint URL.
            timeout: Request timeout in seconds.
        """
        self.api_key = api_key
        self.endpoint = endpoint
        self.timeout = timeout
        self._session: requests.Session | None = None

    @property
    def session(self) -> requests.Session:
        """Get or create a requests session."""
        if self._session is None:
            self._session = requests.Session()
            self._session.headers.update(
                {
                    "Authorization": f"Bearer {self.api_key}",
                    "Content-Type": "application/json",
                }
            )
        return self._session

    def close(self) -> None:
        """Close the HTTP session."""
        if self._session is not None:
            self._session.close()
            self._session = None

    def __enter__(self):
        return self

    def __exit__(self, exc_type, exc_val, exc_tb):
        self.close()
        return False

    def _execute(
        self,
        query: str,
        variables: dict[str, Any] | None = None,
    ) -> dict[str, Any]:
        """
        Execute a GraphQL query or mutation.

        Args:
            query: The GraphQL query or mutation string.
            variables: Optional variables for the query.

        Returns:
            The response data from the API.

        Raises:
            LetzshopAuthError: If authentication fails.
            LetzshopAPIError: If the API returns an error.
            LetzshopConnectionError: If the request fails.
        """
        payload = {"query": query}
        if variables:
            payload["variables"] = variables

        logger.debug(f"Executing GraphQL request to {self.endpoint}")

        try:
            response = self.session.post(
                self.endpoint,
                json=payload,
                timeout=self.timeout,
            )
        except requests.exceptions.Timeout as e:
            raise LetzshopConnectionError(f"Request timed out: {e}") from e
        except requests.exceptions.ConnectionError as e:
            raise LetzshopConnectionError(f"Connection failed: {e}") from e
        except requests.exceptions.RequestException as e:
            raise LetzshopConnectionError(f"Request failed: {e}") from e

        # Handle HTTP-level errors
        if response.status_code == 401:
            raise LetzshopAuthError(
                "Authentication failed. Please check your API key.",
                response_data={"status_code": 401},
            )
        if response.status_code == 403:
            raise LetzshopAuthError(
                "Access forbidden. Your API key may not have the required permissions.",
                response_data={"status_code": 403},
            )
        if response.status_code >= 500:
            raise LetzshopAPIError(
                f"Letzshop server error (HTTP {response.status_code})",
                response_data={"status_code": response.status_code},
            )

        # Parse JSON response
        try:
            data = response.json()
        except ValueError as e:
            raise LetzshopAPIError(
                f"Invalid JSON response: {response.text[:200]}"
            ) from e

        # Check for GraphQL errors
        if "errors" in data and data["errors"]:
            error_messages = [
                err.get("message", "Unknown error") for err in data["errors"]
            ]
            raise LetzshopAPIError(
                f"GraphQL errors: {'; '.join(error_messages)}",
                response_data=data,
            )

        return data.get("data", {})

    # ========================================================================
    # Connection Testing
    # ========================================================================

    def test_connection(self) -> tuple[bool, float, str | None]:
        """
        Test the connection to Letzshop API.

        Returns:
            Tuple of (success, response_time_ms, error_message).
        """
        test_query = """
        query TestConnection {
            __typename
        }
        """

        start_time = time.time()

        try:
            self._execute(test_query)
            elapsed_ms = (time.time() - start_time) * 1000
            return True, elapsed_ms, None
        except LetzshopClientError as e:
            elapsed_ms = (time.time() - start_time) * 1000
            return False, elapsed_ms, str(e)

    # ========================================================================
    # Shipment Queries
    # ========================================================================

    def get_shipments(
        self,
        state: str | None = None,
    ) -> list[dict[str, Any]]:
        """
        Get shipments from Letzshop.

        Args:
            state: Optional state filter (e.g., "unconfirmed", "confirmed").

        Returns:
            List of shipment data dictionaries.
        """
        variables = {}
        if state:
            variables["state"] = state

        data = self._execute(QUERY_SHIPMENTS, variables)
        shipments_data = data.get("shipments", {})
        return shipments_data.get("nodes", [])

    def get_unconfirmed_shipments(self) -> list[dict[str, Any]]:
        """Get all unconfirmed shipments."""
        return self.get_shipments(state="unconfirmed")

    def get_shipment_by_id(self, shipment_id: str) -> dict[str, Any] | None:
        """
        Get a single shipment by its ID.

        Args:
            shipment_id: The Letzshop shipment ID.

        Returns:
            Shipment data or None if not found.
        """
        data = self._execute(QUERY_SHIPMENT_BY_ID, {"id": shipment_id})
        return data.get("node")

    # ========================================================================
    # Fulfillment Mutations
    # ========================================================================

    def confirm_inventory_units(
        self,
        inventory_unit_ids: list[str],
    ) -> dict[str, Any]:
        """
        Confirm inventory units for fulfillment.

        Args:
            inventory_unit_ids: List of inventory unit IDs to confirm.

        Returns:
            Response data including confirmed units and any errors.
        """
        variables = {
            "input": {
                "inventoryUnitIds": inventory_unit_ids,
            }
        }

        data = self._execute(MUTATION_CONFIRM_INVENTORY_UNITS, variables)
        return data.get("confirmInventoryUnits", {})

    def reject_inventory_units(
        self,
        inventory_unit_ids: list[str],
    ) -> dict[str, Any]:
        """
        Reject/return inventory units.

        Args:
            inventory_unit_ids: List of inventory unit IDs to reject.

        Returns:
            Response data including rejected units and any errors.
        """
        variables = {
            "input": {
                "inventoryUnitIds": inventory_unit_ids,
            }
        }

        data = self._execute(MUTATION_REJECT_INVENTORY_UNITS, variables)
        return data.get("returnInventoryUnits", {})

    def set_shipment_tracking(
        self,
        shipment_id: str,
        tracking_code: str,
        tracking_provider: str,
    ) -> dict[str, Any]:
        """
        Set tracking information for a shipment.

        Args:
            shipment_id: The Letzshop shipment ID.
            tracking_code: The tracking number.
            tracking_provider: The carrier code (e.g., "dhl", "ups").

        Returns:
            Response data including updated shipment and any errors.
        """
        variables = {
            "input": {
                "shipmentId": shipment_id,
                "tracking": {
                    "code": tracking_code,
                    "provider": tracking_provider,
                },
            }
        }

        data = self._execute(MUTATION_SET_SHIPMENT_TRACKING, variables)
        return data.get("setShipmentTracking", {})