import contextlib
import logging
import platform
from enum import Enum
from typing import Any, Optional

import fastapi
import fastapi.responses
import pydantic
import starlette.middleware.cors
import uvicorn
from autogpt_libs.auth import add_auth_responses_to_openapi
from autogpt_libs.auth import verify_settings as verify_auth_settings
from fastapi.exceptions import RequestValidationError
from fastapi.middleware.gzip import GZipMiddleware
from fastapi.routing import APIRoute
from prisma.errors import PrismaError

import backend.api.features.admin.credit_admin_routes
import backend.api.features.admin.execution_analytics_routes
import backend.api.features.admin.rate_limit_admin_routes
import backend.api.features.admin.store_admin_routes
import backend.api.features.builder
import backend.api.features.builder.routes
import backend.api.features.chat.routes as chat_routes
import backend.api.features.executions.review.routes
import backend.api.features.library.db
import backend.api.features.library.model
import backend.api.features.library.routes
import backend.api.features.mcp.routes as mcp_routes
import backend.api.features.oauth
import backend.api.features.otto.routes
import backend.api.features.platform_linking.routes
import backend.api.features.postmark.postmark
import backend.api.features.store.model
import backend.api.features.store.routes
import backend.api.features.v1
import backend.api.features.workspace.routes as workspace_routes
import backend.data.block
import backend.data.db
import backend.data.graph
import backend.data.user
import backend.integrations.webhooks.utils
import backend.util.service
import backend.util.settings
from backend.api.features.library.exceptions import (
    FolderAlreadyExistsError,
    FolderValidationError,
)
from backend.blocks.llm import DEFAULT_LLM_MODEL
from backend.data.model import Credentials
from backend.integrations.providers import ProviderName
from backend.monitoring.instrumentation import instrument_fastapi
from backend.util import json
from backend.util.cloud_storage import shutdown_cloud_storage_handler
from backend.util.exceptions import (
    MissingConfigError,
    NotAuthorizedError,
    NotFoundError,
    PreconditionFailed,
)
from backend.util.feature_flag import initialize_launchdarkly, shutdown_launchdarkly
from backend.util.service import UnhealthyServiceError
from backend.util.workspace_storage import shutdown_workspace_storage

from .external.fastapi_app import external_api
from .features.analytics import router as analytics_router
from .features.integrations.router import router as integrations_router
from .middleware.security import SecurityHeadersMiddleware
from .utils.cors import build_cors_params
from .utils.openapi import sort_openapi

settings = backend.util.settings.Settings()
logger = logging.getLogger(__name__)

logging.getLogger("autogpt_libs").setLevel(logging.INFO)


@contextlib.contextmanager
def launch_darkly_context():
    if settings.config.app_env != backend.util.settings.AppEnvironment.LOCAL:
        initialize_launchdarkly()
        try:
            yield
        finally:
            shutdown_launchdarkly()
    else:
        yield


@contextlib.asynccontextmanager
async def lifespan_context(app: fastapi.FastAPI):
    verify_auth_settings()

    await backend.data.db.connect()

    # Configure thread pool for FastAPI sync operation performance
    # CRITICAL: FastAPI automatically runs ALL sync functions in this thread pool:
    # - Any endpoint defined with 'def' (not async def)
    # - Any dependency function defined with 'def' (not async def)
    # - Manual run_in_threadpool() calls (like JWT decoding)
    # Default pool size is only 40 threads, causing bottlenecks under high concurrency
    config = backend.util.settings.Config()
    try:
        import anyio.to_thread

        anyio.to_thread.current_default_thread_limiter().total_tokens = (
            config.fastapi_thread_pool_size
        )
        logger.info(
            f"Thread pool size set to {config.fastapi_thread_pool_size} for sync endpoint/dependency performance"
        )
    except (ImportError, AttributeError) as e:
        logger.warning(f"Could not configure thread pool size: {e}")
        # Continue without thread pool configuration

    # Ensure SDK auto-registration is patched before initializing blocks
    from backend.sdk.registry import AutoRegistry

    AutoRegistry.patch_integrations()

    await backend.data.block.initialize_blocks()

    await backend.data.user.migrate_and_encrypt_user_integrations()
    await backend.data.graph.fix_llm_provider_credentials()
    await backend.data.graph.migrate_llm_models(DEFAULT_LLM_MODEL)
    await backend.integrations.webhooks.utils.migrate_legacy_triggered_graphs()

    with launch_darkly_context():
        yield

    try:
        await shutdown_cloud_storage_handler()
    except Exception as e:
        logger.warning(f"Error shutting down cloud storage handler: {e}")

    try:
        await shutdown_workspace_storage()
    except Exception as e:
        logger.warning(f"Error shutting down workspace storage: {e}")

    await backend.data.db.disconnect()


def custom_generate_unique_id(route: APIRoute):
    """Generate clean operation IDs for OpenAPI spec following the format:
    {method}{tag}{summary}
    """
    if not route.tags or not route.methods:
        return f"{route.name}"

    method = list(route.methods)[0].lower()
    first_tag = route.tags[0]
    if isinstance(first_tag, Enum):
        tag_str = first_tag.name
    else:
        tag_str = str(first_tag)

    tag = "".join(word.capitalize() for word in tag_str.split("_"))  # v1/v2

    summary = (
        route.summary if route.summary else route.name
    )  # need to be unique, a different version could have the same summary
    summary = "".join(word.capitalize() for word in str(summary).split("_"))

    if tag:
        return f"{method}{tag}{summary}"
    else:
        return f"{method}{summary}"


docs_url = (
    "/docs"
    if settings.config.app_env == backend.util.settings.AppEnvironment.LOCAL
    else None
)

app = fastapi.FastAPI(
    title="AutoGPT Agent Server",
    description=(
        "This server is used to execute agents that are created by the AutoGPT system."
    ),
    summary="AutoGPT Agent Server",
    version="0.1",
    lifespan=lifespan_context,
    docs_url=docs_url,
    generate_unique_id_function=custom_generate_unique_id,
)

app.add_middleware(SecurityHeadersMiddleware)

# Add GZip compression middleware for large responses (like /api/blocks)
app.add_middleware(GZipMiddleware, minimum_size=50_000)  # 50KB threshold

# Add 401 responses to authenticated endpoints in OpenAPI spec
add_auth_responses_to_openapi(app)

# Sort OpenAPI schema to eliminate diff on refactors
sort_openapi(app)

# Add Prometheus instrumentation
instrument_fastapi(
    app,
    service_name="rest-api",
    expose_endpoint=True,
    endpoint="/metrics",
    include_in_schema=settings.config.app_env
    == backend.util.settings.AppEnvironment.LOCAL,
)


def handle_internal_http_error(status_code: int = 500, log_error: bool = True):
    def handler(request: fastapi.Request, exc: Exception):
        if log_error:
            if status_code >= 500:
                logger.exception(
                    "%s %s failed. Investigate and resolve the underlying issue: %s",
                    request.method,
                    request.url.path,
                    exc,
                    exc_info=exc,
                )
            else:
                logger.warning(
                    "%s %s failed with %d: %s",
                    request.method,
                    request.url.path,
                    status_code,
                    exc,
                )

        hint = (
            "Adjust the request and retry."
            if status_code < 500
            else "Check server logs and dependent services."
        )
        return fastapi.responses.JSONResponse(
            content={
                "message": f"Failed to process {request.method} {request.url.path}",
                "detail": str(exc),
                "hint": hint,
            },
            status_code=status_code,
        )

    return handler


async def validation_error_handler(
    request: fastapi.Request, exc: Exception
) -> fastapi.responses.Response:
    logger.error(
        "Validation failed for %s %s: %s. Fix the request payload and try again.",
        request.method,
        request.url.path,
        exc,
    )
    errors: list | str
    if hasattr(exc, "errors"):
        errors = exc.errors()  # type: ignore[call-arg]
    else:
        errors = str(exc)

    response_content = {
        "message": f"Invalid data for {request.method} {request.url.path}",
        "detail": errors,
        "hint": "Ensure the request matches the API schema.",
    }

    content_json = json.dumps(response_content)

    return fastapi.responses.Response(
        content=content_json,
        status_code=422,
        media_type="application/json",
    )


app.add_exception_handler(PrismaError, handle_internal_http_error(500))
app.add_exception_handler(FolderAlreadyExistsError, handle_internal_http_error(409))
app.add_exception_handler(FolderValidationError, handle_internal_http_error(400))
app.add_exception_handler(NotFoundError, handle_internal_http_error(404))
app.add_exception_handler(NotAuthorizedError, handle_internal_http_error(403))
app.add_exception_handler(RequestValidationError, validation_error_handler)
app.add_exception_handler(pydantic.ValidationError, validation_error_handler)
app.add_exception_handler(MissingConfigError, handle_internal_http_error(503))
app.add_exception_handler(ValueError, handle_internal_http_error(400))
app.add_exception_handler(PreconditionFailed, handle_internal_http_error(428))
app.add_exception_handler(Exception, handle_internal_http_error(500))

app.include_router(backend.api.features.v1.v1_router, tags=["v1"], prefix="/api")
app.include_router(
    integrations_router,
    prefix="/api/integrations",
    tags=["v1", "integrations"],
)
app.include_router(
    analytics_router,
    prefix="/api/analytics",
    tags=["analytics"],
)
app.include_router(
    backend.api.features.store.routes.router, tags=["v2"], prefix="/api/store"
)
app.include_router(
    backend.api.features.builder.routes.router, tags=["v2"], prefix="/api/builder"
)
app.include_router(
    backend.api.features.admin.store_admin_routes.router,
    tags=["v2", "admin"],
    prefix="/api/store",
)
app.include_router(
    backend.api.features.admin.credit_admin_routes.router,
    tags=["v2", "admin"],
    prefix="/api/credits",
)
app.include_router(
    backend.api.features.admin.execution_analytics_routes.router,
    tags=["v2", "admin"],
    prefix="/api/executions",
)
app.include_router(
    backend.api.features.admin.rate_limit_admin_routes.router,
    tags=["v2", "admin"],
    prefix="/api/copilot",
)
app.include_router(
    backend.api.features.executions.review.routes.router,
    tags=["v2", "executions", "review"],
    prefix="/api/review",
)
app.include_router(
    backend.api.features.library.routes.router, tags=["v2"], prefix="/api/library"
)
app.include_router(
    backend.api.features.otto.routes.router, tags=["v2", "otto"], prefix="/api/otto"
)

app.include_router(
    backend.api.features.postmark.postmark.router,
    tags=["v1", "email"],
    prefix="/api/email",
)
app.include_router(
    chat_routes.router,
    tags=["v2", "chat"],
    prefix="/api/chat",
)
app.include_router(
    workspace_routes.router,
    tags=["workspace"],
    prefix="/api/workspace",
)
app.include_router(
    mcp_routes.router,
    tags=["v2", "mcp"],
    prefix="/api/mcp",
)
app.include_router(
    backend.api.features.oauth.router,
    tags=["oauth"],
    prefix="/api/oauth",
)
app.include_router(
    backend.api.features.platform_linking.routes.router,
    tags=["platform-linking"],
    prefix="/api/platform-linking",
)

app.mount("/external-api", external_api)


@app.get(path="/health", tags=["health"], dependencies=[])
async def health():
    if not backend.data.db.is_connected():
        raise UnhealthyServiceError("Database is not connected")
    return {"status": "healthy"}


class AgentServer(backend.util.service.AppProcess):
    def run(self):
        cors_params = build_cors_params(
            settings.config.backend_cors_allow_origins,
            settings.config.app_env,
        )

        server_app = starlette.middleware.cors.CORSMiddleware(
            app=app,
            **cors_params,
            allow_credentials=True,
            allow_methods=["*"],  # Allows all methods
            allow_headers=["*"],  # Allows all headers
        )

        # Only add debug in local environment (not supported in all uvicorn versions)
        if settings.config.app_env == backend.util.settings.AppEnvironment.LOCAL:
            import os

            # Enable asyncio debug mode via environment variable
            os.environ["PYTHONASYNCIODEBUG"] = "1"

        # Configure uvicorn with performance optimizations from Kludex FastAPI tips
        uvicorn.run(
            app=server_app,
            host=settings.config.agent_api_host,
            port=settings.config.agent_api_port,
            log_config=None,
            # Use httptools for HTTP parsing (if available)
            http="httptools",
            # Only use uvloop on Unix-like systems (not supported on Windows)
            loop="uvloop" if platform.system() != "Windows" else "auto",
            # Disable WebSockets since this service doesn't have any WebSocket endpoints
            ws="none",
        )

    @staticmethod
    async def test_execute_graph(
        graph_id: str,
        user_id: str,
        graph_version: Optional[int] = None,
        node_input: Optional[dict[str, Any]] = None,
    ):
        return await backend.api.features.v1.execute_graph(
            user_id=user_id,
            graph_id=graph_id,
            graph_version=graph_version,
            inputs=node_input or {},
            credentials_inputs={},
        )

    @staticmethod
    async def test_get_graph(
        graph_id: str,
        graph_version: int,
        user_id: str,
        for_export: bool = False,
    ):
        return await backend.api.features.v1.get_graph(
            graph_id, user_id, graph_version, for_export
        )

    @staticmethod
    async def test_create_graph(
        create_graph: backend.api.features.v1.CreateGraph,
        user_id: str,
    ):
        return await backend.api.features.v1.create_new_graph(create_graph, user_id)

    @staticmethod
    async def test_get_graph_run_status(graph_exec_id: str, user_id: str):
        from backend.data.execution import get_graph_execution_meta

        execution = await get_graph_execution_meta(
            user_id=user_id, execution_id=graph_exec_id
        )
        if not execution:
            raise ValueError(f"Execution {graph_exec_id} not found")
        return execution.status

    @staticmethod
    async def test_delete_graph(graph_id: str, user_id: str):
        """Used for clean-up after a test run"""
        await backend.api.features.library.db.delete_library_agent_by_graph_id(
            graph_id=graph_id, user_id=user_id
        )
        return await backend.api.features.v1.delete_graph(graph_id, user_id)

    @staticmethod
    async def test_get_presets(user_id: str, page: int = 1, page_size: int = 10):
        return await backend.api.features.library.routes.presets.list_presets(
            user_id=user_id, page=page, page_size=page_size
        )

    @staticmethod
    async def test_get_preset(preset_id: str, user_id: str):
        return await backend.api.features.library.routes.presets.get_preset(
            preset_id=preset_id, user_id=user_id
        )

    @staticmethod
    async def test_create_preset(
        preset: backend.api.features.library.model.LibraryAgentPresetCreatable,
        user_id: str,
    ):
        return await backend.api.features.library.routes.presets.create_preset(
            preset=preset, user_id=user_id
        )

    @staticmethod
    async def test_update_preset(
        preset_id: str,
        preset: backend.api.features.library.model.LibraryAgentPresetUpdatable,
        user_id: str,
    ):
        return await backend.api.features.library.routes.presets.update_preset(
            preset_id=preset_id, preset=preset, user_id=user_id
        )

    @staticmethod
    async def test_delete_preset(preset_id: str, user_id: str):
        return await backend.api.features.library.routes.presets.delete_preset(
            preset_id=preset_id, user_id=user_id
        )

    @staticmethod
    async def test_execute_preset(
        preset_id: str,
        user_id: str,
        inputs: Optional[dict[str, Any]] = None,
    ):
        return await backend.api.features.library.routes.presets.execute_preset(
            preset_id=preset_id,
            user_id=user_id,
            inputs=inputs or {},
            credential_inputs={},
        )

    @staticmethod
    async def test_create_store_listing(
        request: backend.api.features.store.model.StoreSubmissionRequest, user_id: str
    ):
        return await backend.api.features.store.routes.create_submission(
            request, user_id
        )

    ### ADMIN ###

    @staticmethod
    async def test_review_store_listing(
        request: backend.api.features.store.model.ReviewSubmissionRequest,
        user_id: str,
    ):
        return await backend.api.features.admin.store_admin_routes.review_submission(
            request.store_listing_version_id, request, user_id
        )

    @staticmethod
    async def test_create_credentials(
        user_id: str,
        provider: ProviderName,
        credentials: Credentials,
    ):
        from backend.api.features.integrations.router import (
            create_credentials,
            get_credential,
        )

        try:
            return await create_credentials(
                user_id=user_id, provider=provider, credentials=credentials
            )
        except Exception as e:
            logger.error(f"Error creating credentials: {e}")
            return await get_credential(
                provider=provider,
                user_id=user_id,
                cred_id=credentials.id,
            )

    def set_test_dependency_overrides(self, overrides: dict):
        app.dependency_overrides.update(overrides)
