"""Session CRUD endpoints.

This module provides API endpoints for creating, reading, updating,
and deleting session data.
"""

from __future__ import annotations

from fastapi import APIRouter, HTTPException, Query
from pydantic import BaseModel, Field

router = APIRouter()


class SessionSummary(BaseModel):
    """Summary of a session for list views.

    Attributes
    ----------
    session_id
        Unique identifier for the session.
    created_at
        ISO 8601 timestamp of session creation.
    trial_count
        Number of trials in the session.
    has_verdict
        Whether the session has been analyzed.
    """

    session_id: str = Field(description="Unique session identifier")
    created_at: str = Field(description="ISO 8601 timestamp")
    trial_count: int = Field(ge=0, description="Number of trials")
    has_verdict: bool = Field(description="Whether analysis verdict exists")


class SessionListResponse(BaseModel):
    """Paginated response for session list endpoint.

    Attributes
    ----------
    sessions
        List of session summaries for the current page.
    total
        Total number of sessions matching the query.
    page
        Current page number (1-indexed).
    page_size
        Number of sessions per page.
    """

    sessions: list[SessionSummary] = Field(description="Session summaries")
    total: int = Field(ge=0, description="Total matching sessions")
    page: int = Field(ge=1, description="Current page number")
    page_size: int = Field(ge=1, description="Sessions per page")


class SessionDetail(BaseModel):
    """Full session details.

    Attributes
    ----------
    session_id
        Unique identifier for the session.
    created_at
        ISO 8601 timestamp of session creation.
    trial_count
        Number of trials in the session.
    metadata
        Additional session metadata.
    """

    session_id: str = Field(description="Unique session identifier")
    created_at: str = Field(description="ISO 8601 timestamp")
    trial_count: int = Field(ge=0, description="Number of trials")
    metadata: dict[str, str | int | float | bool | None] = Field(
        default_factory=dict, description="Session metadata"
    )


class TrialSummary(BaseModel):
    """Summary of a trial within a session.

    Attributes
    ----------
    trial_index
        Zero-based index of the trial.
    trial_type
        Type or name of the trial.
    has_keystrokes
        Whether keystroke data was captured.
    response_length
        Character count of the response text.
    """

    trial_index: int = Field(ge=0, description="Trial index")
    trial_type: str = Field(description="Trial type identifier")
    has_keystrokes: bool = Field(description="Whether keystrokes exist")
    response_length: int = Field(ge=0, description="Response character count")


class VerdictResponse(BaseModel):
    """Analysis verdict for a session.

    Attributes
    ----------
    session_id
        Unique identifier for the session.
    verdict
        Overall verdict (human, ai_assisted, uncertain).
    confidence
        Confidence score from 0 to 1.
    flags
        List of triggered detection flags.
    """

    session_id: str = Field(description="Session identifier")
    verdict: str = Field(description="Analysis verdict")
    confidence: float = Field(ge=0.0, le=1.0, description="Confidence score")
    flags: list[str] = Field(default_factory=list, description="Triggered flags")


@router.get("/", response_model=SessionListResponse)
async def list_sessions(
    page: int = Query(default=1, ge=1, description="Page number"),
    page_size: int = Query(default=20, ge=1, le=100, description="Sessions per page"),
    has_verdict: bool | None = Query(default=None, description="Filter by verdict status"),
) -> SessionListResponse:
    """List sessions with pagination.

    Returns a paginated list of session summaries. Use the has_verdict
    parameter to filter sessions by their analysis status.

    Parameters
    ----------
    page
        Page number to retrieve (1-indexed).
    page_size
        Number of sessions per page (max 100).
    has_verdict
        Filter by whether sessions have been analyzed.

    Returns
    -------
    SessionListResponse
        Paginated list of session summaries.
    """
    # TODO: Implement with storage service
    _ = has_verdict  # Suppress unused variable warning
    return SessionListResponse(sessions=[], total=0, page=page, page_size=page_size)


@router.get("/{session_id}", response_model=SessionDetail)
async def get_session(session_id: str) -> SessionDetail:
    """Get session details.

    Retrieves full details for a specific session, including metadata
    and trial count.

    Parameters
    ----------
    session_id
        Unique identifier of the session to retrieve.

    Returns
    -------
    SessionDetail
        Full session details.

    Raises
    ------
    HTTPException
        404 if session not found.
    """
    # TODO: Implement with storage service
    raise HTTPException(status_code=404, detail=f"Session not found: {session_id}")


@router.get("/{session_id}/trials", response_model=list[TrialSummary])
async def get_session_trials(session_id: str) -> list[TrialSummary]:
    """Get trials for a session.

    Retrieves summary information for all trials within a session.

    Parameters
    ----------
    session_id
        Unique identifier of the session.

    Returns
    -------
    list[TrialSummary]
        List of trial summaries.

    Raises
    ------
    HTTPException
        404 if session not found.
    """
    # TODO: Implement with storage service
    _ = session_id  # Suppress unused variable warning
    return []


@router.get("/{session_id}/verdict", response_model=VerdictResponse)
async def get_session_verdict(session_id: str) -> VerdictResponse:
    """Get verdict for a session.

    Retrieves the analysis verdict and associated flags for a session.

    Parameters
    ----------
    session_id
        Unique identifier of the session.

    Returns
    -------
    VerdictResponse
        Analysis verdict with confidence and flags.

    Raises
    ------
    HTTPException
        404 if session or verdict not found.
    """
    # TODO: Implement with analysis service
    raise HTTPException(status_code=404, detail=f"Verdict not found for session: {session_id}")
