# Copyright © The Debusine Developers
# See the AUTHORS file at the top-level directory of this distribution
#
# This file is part of Debusine. It is subject to the license terms
# in the LICENSE file found in the top-level directory of this
# distribution. No part of Debusine, including this file, may be copied,
# modified, propagated, or distributed except according to the terms
# contained in the LICENSE file.

"""Models used for worker pool data."""

import abc
from enum import StrEnum
from typing import Any, Literal, Self

import pydantic

from debusine.assets import CloudProvidersType
from debusine.tasks.models import ExtraExternalRepository


class BaseWorkerPoolDataModel(pydantic.BaseModel, abc.ABC):
    """Base pydantic model for worker pool configuration."""

    model_config = pydantic.ConfigDict(validate_assignment=True, extra="forbid")


_worker_pool_specifications_models: dict[
    CloudProvidersType, type["WorkerPoolSpecifications"]
] = {}


class WorkerPoolSpecifications(BaseWorkerPoolDataModel, abc.ABC):
    """Base class for WorkerPool.specifications data models."""

    provider_type: CloudProvidersType

    def __init_subclass__(
        cls,
        provider_type: CloudProvidersType,
        **kwargs: Any,
    ) -> None:
        """Register subclass in _worker_pool_specifications_models."""
        super().__init_subclass__(**kwargs)
        _worker_pool_specifications_models[provider_type] = cls


def worker_pool_specifications_model(
    data: dict[str, Any],
) -> WorkerPoolSpecifications:
    """Load the WorkerPoolSpecifications subclass model for data."""
    model = _worker_pool_specifications_models[data["provider_type"]]
    return model.model_validate(data)


class WorkerPoolLimits(BaseWorkerPoolDataModel):
    """Specifications for limits on a WorkerPool."""

    max_active_instances: int | None = None
    target_max_seconds_per_month: int | None = None
    max_idle_seconds: int = 3600


class ScopeWorkerPoolLimits(BaseWorkerPoolDataModel):
    """Specifications for limits on a WorkerPool."""

    target_max_seconds_per_month: int | None = None
    target_latency_seconds: int | None = None


# Test Dummy:


class DummyWorkerPoolSpecification(
    WorkerPoolSpecifications, provider_type=CloudProvidersType.DUMMY
):
    """Specifications for a DummyWorkerPool."""

    provider_type: Literal[CloudProvidersType.DUMMY] = CloudProvidersType.DUMMY
    features: list[str] = []


# Amazon AWS EC2:


class DebianRelease(StrEnum):
    """Debian release that the image is based on."""

    TRIXIE = "trixie"
    FORKY = "forky"


class DebusineInstallSource(StrEnum):
    """Source for installing debusine-worker."""

    RELEASE = "release"
    BACKPORTS = "backports"
    DAILY_BUILDS = "daily-builds"
    CUSTOM = "custom"
    ENTERPRISE_STAGING = "enterprise-staging"
    ENTERPRISE = "enterprise"
    PRE_INSTALLED = "pre-installed"


class AWSEC2InstanceMarketType(StrEnum):
    """Market to purche AWS EC2 instances in."""

    ON_DEMAND = "on-demand"
    SPOT = "spot"


class MinMaxRequirements(BaseWorkerPoolDataModel):
    """Minimum and Optional Maximum Requirements."""

    Min: int
    Max: int | None = None


class AWSInstanceRequirementFilterEnum(StrEnum):
    """Values for AWSEC2InstanceRequirements options that select features."""

    INCLUDED = "included"
    EXCLUDED = "excluded"
    REQUIRED = "required"


class AWSEC2InstanceRequirements(BaseWorkerPoolDataModel):
    """AWS EC2 Instance Requirements."""

    VCpuCount: MinMaxRequirements
    MemoryMiB: MinMaxRequirements
    MemoryGiBPerVCpu: MinMaxRequirements | None = None
    SpotMaxPricePercentageOverLowestPrice: int | None = None
    MaxSpotPriceAsPercentageOfOptimalOnDemandPrice: int | None = None
    BurstablePerformance: AWSInstanceRequirementFilterEnum = (
        AWSInstanceRequirementFilterEnum.EXCLUDED
    )
    AllowedInstanceTypes: list[str] | None = None
    ExcludedInstanceTypes: list[str] | None = None


class AWSEC2NetworkInterface(BaseWorkerPoolDataModel):
    """AWS EC2 Network Interface."""

    AssociatePublicIpAddress: bool | None = None
    DeleteOnTermination: bool = True
    DeviceIndex: int = 0
    Ipv6AddressCount: int | None = None
    SubnetId: str | None = None
    Groups: list[str] | None = None

    @pydantic.field_validator("Groups")
    @classmethod
    def validate_groups(cls, value: list[str] | None) -> list[str] | None:
        """Ensure Groups is not an empty list."""
        if not value:
            return None
        return value


class AWSEC2LaunchTemplate(BaseWorkerPoolDataModel):
    """AWS EC2 Launch Template."""

    EbsOptimized: bool = False
    ImageId: str
    KeyName: str | None = None
    InstanceType: str | None = None
    InstanceRequirements: AWSEC2InstanceRequirements | None = None
    NetworkInterfaces: list[AWSEC2NetworkInterface] | None = None
    # In GiB:
    root_device_size: int | None = None
    swap_size: int | None = None
    tags: dict[str, str] = {}

    @pydantic.field_validator("NetworkInterfaces", mode="after")
    @classmethod
    def validate_network_interfaces(
        cls, value: list[AWSEC2NetworkInterface] | None
    ) -> list[AWSEC2NetworkInterface] | None:
        """Ensure NetworkInterfaces have unique indices and not empty list."""
        if value is None or len(value) == 0:
            return None
        if len({interface.DeviceIndex for interface in value}) < len(value):
            raise ValueError(
                "Each NetworkInterface's DeviceIndex must be unique"
            )
        return value

    @pydantic.model_validator(mode="after")
    def instance_type_or_requirements(self) -> Self:
        """Only one of InstanceType or InstanceRequirements is specified."""
        type_defined = self.InstanceType is not None
        req_defined = self.InstanceRequirements is not None
        if type_defined and req_defined:
            raise ValueError(
                "If InstanceType is specified, InstanceRequirements cannot be"
            )
        if not type_defined and not req_defined:
            raise ValueError(
                "InstanceType or InstanceRequirements must be specified"
            )
        return self


class AWSEC2WorkerPoolSpecification(
    WorkerPoolSpecifications, provider_type=CloudProvidersType.AWS
):
    """Specifications for an AWS EC2 WorkerPool."""

    provider_type: Literal[CloudProvidersType.AWS] = CloudProvidersType.AWS
    launch_templates: list[AWSEC2LaunchTemplate]
    instance_market_type: AWSEC2InstanceMarketType = (
        AWSEC2InstanceMarketType.SPOT
    )
    # Spot:
    max_spot_price_per_hour: float | None = None
    debian_release: DebianRelease | None = None
    debusine_install_source: DebusineInstallSource = (
        DebusineInstallSource.RELEASE
    )
    debusine_install_source_custom: ExtraExternalRepository | None = None


# Hetzner Cloud:


class HetznerCloudWorkerPoolSpecification(
    WorkerPoolSpecifications, provider_type=CloudProvidersType.HETZNER
):
    """Specifications for a Hetzner Cloud WorkerPool."""

    provider_type: Literal[CloudProvidersType.HETZNER] = (
        CloudProvidersType.HETZNER
    )
    server_type: str
    image_name: str
    ssh_keys: list[str] = []
    networks: list[str] = []
    location: str | None = None
    labels: dict[str, str] = {}
    enable_ipv4: bool = True
    enable_ipv6: bool = True
    debian_release: DebianRelease | None = None
    debusine_install_source: DebusineInstallSource = (
        DebusineInstallSource.RELEASE
    )
    debusine_install_source_custom: ExtraExternalRepository | None = None
