"""Project context utilities for Basic Memory MCP server.

Provides project lookup utilities for MCP tools.
Handles project validation and context management in one place.

Note: This module uses ProjectResolver for unified project resolution.
The resolve_project_parameter function is a thin wrapper for backwards
compatibility with existing MCP tools.
"""

from typing import Optional, List
from httpx import AsyncClient
from httpx._types import (
    HeaderTypes,
)
from loguru import logger
from fastmcp import Context

from basic_memory.config import ConfigManager
from basic_memory.project_resolver import ProjectResolver
from basic_memory.schemas.project_info import ProjectItem, ProjectList
from basic_memory.schemas.v2 import ProjectResolveResponse


async def resolve_project_parameter(
    project: Optional[str] = None,
    allow_discovery: bool = False,
    cloud_mode: Optional[bool] = None,
    default_project_mode: Optional[bool] = None,
    default_project: Optional[str] = None,
) -> Optional[str]:
    """Resolve project parameter using unified linear priority chain.

    This is a thin wrapper around ProjectResolver for backwards compatibility.
    New code should consider using ProjectResolver directly for more detailed
    resolution information.

    Resolution order (same for local and cloud modes):
    1. ENV_CONSTRAINT: BASIC_MEMORY_MCP_PROJECT env var (highest priority)
    2. EXPLICIT: project parameter passed directly
    3. DEFAULT: default project when default_project_mode=true
    4. Fallback: cloud → CLOUD_DISCOVERY or ValueError; local → NONE

    Args:
        project: Optional explicit project parameter
        allow_discovery: If True, allows returning None in cloud mode for discovery mode
            (used by tools like recent_activity that can operate across all projects)
        cloud_mode: Optional explicit cloud mode. If not provided, reads from ConfigManager.
        default_project_mode: Optional explicit default project mode. If not provided, reads from ConfigManager.
        default_project: Optional explicit default project. If not provided, reads from ConfigManager.

    Returns:
        Resolved project name or None if no resolution possible
    """
    # Load config for any values not explicitly provided
    if cloud_mode is None or default_project_mode is None or default_project is None:
        config = ConfigManager().config
        if cloud_mode is None:
            cloud_mode = config.cloud_mode
        if default_project_mode is None:
            default_project_mode = config.default_project_mode
        if default_project is None:
            default_project = config.default_project

    # Create resolver with configuration and resolve
    resolver = ProjectResolver.from_env(
        cloud_mode=cloud_mode,
        default_project_mode=default_project_mode,
        default_project=default_project,
    )
    result = resolver.resolve(project=project, allow_discovery=allow_discovery)
    return result.project


async def get_project_names(client: AsyncClient, headers: HeaderTypes | None = None) -> List[str]:
    # Deferred import to avoid circular dependency with tools
    from basic_memory.mcp.tools.utils import call_get

    response = await call_get(client, "/v2/projects/", headers=headers)
    project_list = ProjectList.model_validate(response.json())
    return [project.name for project in project_list.projects]


async def get_active_project(
    client: AsyncClient,
    project: Optional[str] = None,
    context: Optional[Context] = None,
    headers: HeaderTypes | None = None,
) -> ProjectItem:
    """Get and validate project, setting it in context if available.

    Args:
        client: HTTP client for API calls
        project: Optional project name (resolved using hierarchy)
        context: Optional FastMCP context to cache the result

    Returns:
        The validated project item

    Raises:
        ValueError: If no project can be resolved
        HTTPError: If project doesn't exist or is inaccessible
    """
    # Deferred import to avoid circular dependency with tools
    from basic_memory.mcp.tools.utils import call_post

    resolved_project = await resolve_project_parameter(project)
    if not resolved_project:
        project_names = await get_project_names(client, headers)
        raise ValueError(
            "No project specified. "
            "Either set 'default_project_mode=true' in config, or use 'project' argument.\n"
            f"Available projects: {project_names}"
        )

    project = resolved_project

    # Check if already cached in context
    if context:
        cached_project = context.get_state("active_project")
        if cached_project and cached_project.name == project:
            logger.debug(f"Using cached project from context: {project}")
            return cached_project

    # Validate project exists by calling API
    logger.debug(f"Validating project: {project}")
    response = await call_post(
        client,
        "/v2/projects/resolve",
        json={"identifier": project},
        headers=headers,
    )
    resolved = ProjectResolveResponse.model_validate(response.json())
    active_project = ProjectItem(
        id=resolved.project_id,
        external_id=resolved.external_id,
        name=resolved.name,
        path=resolved.path,
        is_default=resolved.is_default,
    )

    # Cache in context if available
    if context:
        context.set_state("active_project", active_project)
        logger.debug(f"Cached project in context: {project}")

    logger.debug(f"Validated project: {active_project.name}")
    return active_project


def add_project_metadata(result: str, project_name: str) -> str:
    """Add project context as metadata footer for assistant session tracking.

    Provides clear project context to help the assistant remember which
    project is being used throughout the conversation session.

    Args:
        result: The tool result string
        project_name: The project name that was used

    Returns:
        Result with project session tracking metadata
    """
    return f"{result}\n\n[Session: Using project '{project_name}']"