"""
Pydantic schemas for terminal session API.
"""
from datetime import datetime
from typing import List, Optional, Literal, Any

from pydantic import BaseModel, Field


# ============================================================================
# Command History Schemas
# ============================================================================

class CommandHistoryItem(BaseModel):
    """A single command from history."""
    id: int
    command: str
    created_at: datetime
    host_name: Optional[str] = None
    username: Optional[str] = None
    execution_count: Optional[int] = None
    
    class Config:
        from_attributes = True


class CommandHistoryResponse(BaseModel):
    """Response containing command history."""
    commands: List[CommandHistoryItem]
    total: int
    host_id: Optional[str] = None
    query: Optional[str] = None


class UniqueCommandItem(BaseModel):
    """A unique command with usage stats."""
    command: str
    command_hash: str
    last_used: datetime
    execution_count: int


class UniqueCommandsResponse(BaseModel):
    """Response containing unique commands."""
    commands: List[UniqueCommandItem]
    total: int
    host_id: str


# ============================================================================
# Terminal Session Schemas
# ============================================================================

class TerminalSessionRequest(BaseModel):
    """Request to create a new terminal session."""
    mode: Literal["embedded", "popout"] = Field(
        default="embedded",
        description="Terminal display mode: embedded in drawer or popout window"
    )


class TerminalSessionHost(BaseModel):
    """Host information included in session response."""
    id: str
    name: str
    ip: str
    status: str
    bootstrap_ok: bool


class TerminalSessionResponse(BaseModel):
    """Response after creating a terminal session."""
    session_id: str
    url: str
    websocket_url: str
    expires_at: datetime
    ttl_seconds: int
    mode: str
    host: TerminalSessionHost
    reused: bool = False  # True if an existing session was reused
    token: Optional[str] = None  # Only provided for new sessions


class TerminalSessionStatus(BaseModel):
    """Current status of a terminal session."""
    session_id: str
    status: str
    host_id: str
    host_name: str
    mode: str = "embedded"
    created_at: datetime
    expires_at: datetime
    last_seen_at: Optional[datetime] = None
    remaining_seconds: int
    age_seconds: int = 0
    last_seen_seconds: int = 0


class TerminalSessionList(BaseModel):
    """List of active terminal sessions."""
    sessions: list[TerminalSessionStatus]
    total: int
    max_per_user: int


class ActiveSessionInfo(BaseModel):
    """Info about an active session for limit error response."""
    session_id: str
    host_id: str
    host_name: str
    mode: str
    age_seconds: int
    last_seen_seconds: int


class SessionLimitError(BaseModel):
    """Rich error response when session limit is exceeded."""
    error: str = "SESSION_LIMIT"
    message: str
    max_active: int
    current_count: int
    active_sessions: List[ActiveSessionInfo]
    suggested_actions: List[str]
    can_reuse: bool = False
    reusable_session_id: Optional[str] = None


class HeartbeatRequest(BaseModel):
    """Request to update session heartbeat."""
    pass  # Empty body, session_id comes from path


class HeartbeatResponse(BaseModel):
    """Response from heartbeat endpoint."""
    session_id: str
    status: str
    last_seen_at: datetime
    remaining_seconds: int
    healthy: bool = True


class CloseBeaconRequest(BaseModel):
    """Request from sendBeacon to close session."""
    reason: str = "client_close"


class SessionMetrics(BaseModel):
    """Terminal session service metrics."""
    sessions_created: int
    sessions_reused: int
    sessions_closed_user: int
    sessions_gc_expired: int
    sessions_gc_idle: int
    session_limit_hits: int
    active_processes: int
    allocated_ports: int
    gc_running: bool