"""
Session Manager for KB Capture (Simplified)

One session = one continuous recording (with pause/resume).
No clips, no keep/delete. Just record → transcribe → done.
"""

import json
from pathlib import Path
from dataclasses import dataclass
from datetime import datetime
from typing import Optional, List
from enum import Enum


class SessionType(Enum):
    DESIGN = "design"      # CAD/Design KB
    ANALYSIS = "analysis"  # FEA/Analysis KB


class SessionStatus(Enum):
    RECORDING = "recording"
    PAUSED = "paused"
    TRANSCRIBING = "transcribing"
    READY = "ready"        # Transcribed, ready for sync
    PROCESSED = "processed"  # Clawdbot has processed it


@dataclass
class Session:
    """A recording session."""
    id: str
    name: str
    project: str
    session_type: SessionType
    created_at: datetime
    duration: float = 0.0
    status: SessionStatus = SessionStatus.RECORDING
    video_file: str = "recording.mp4"
    transcript_file: Optional[str] = None
    
    def to_dict(self) -> dict:
        return {
            "id": self.id,
            "name": self.name,
            "project": self.project,
            "session_type": self.session_type.value,
            "created_at": self.created_at.isoformat(),
            "duration": self.duration,
            "status": self.status.value,
            "video_file": self.video_file,
            "transcript_file": self.transcript_file,
        }
    
    @classmethod
    def from_dict(cls, data: dict) -> "Session":
        return cls(
            id=data["id"],
            name=data["name"],
            project=data["project"],
            session_type=SessionType(data.get("session_type", "design")),
            created_at=datetime.fromisoformat(data["created_at"]),
            duration=data.get("duration", 0.0),
            status=SessionStatus(data.get("status", "ready")),
            video_file=data.get("video_file", "recording.mp4"),
            transcript_file=data.get("transcript_file"),
        )


class SessionManager:
    """
    Manages recording sessions.
    
    Project-centric structure:
        /Projects/<ProjectName>/
        └── _capture/
            └── <session-id>/
                ├── session.json      # Metadata
                ├── recording.mp4     # Video
                └── transcript.json   # Whisper output
    """
    
    def __init__(self, projects_root: Path):
        self.projects_root = Path(projects_root)
        self.current_session: Optional[Session] = None
        self._current_project_path: Optional[Path] = None
    
    def list_projects(self) -> List[str]:
        """List available projects."""
        projects = []
        if self.projects_root.exists():
            for p in sorted(self.projects_root.iterdir()):
                if p.is_dir() and not p.name.startswith((".", "_")):
                    # Check if it looks like a project
                    if (p / "KB").exists() or (p / "_context.md").exists():
                        projects.append(p.name)
        return projects
    
    def get_project_path(self, project: str) -> Path:
        """Get full path to a project."""
        return self.projects_root / project
    
    def start_session(
        self,
        name: str,
        project: str,
        session_type: SessionType = SessionType.DESIGN,
    ) -> Session:
        """Start a new recording session."""
        self._current_project_path = self.get_project_path(project)
        if not self._current_project_path.exists():
            raise ValueError(f"Project not found: {project}")
        
        session_id = datetime.now().strftime("%Y%m%d-%H%M%S")
        
        session = Session(
            id=session_id,
            name=name,
            project=project,
            session_type=session_type,
            created_at=datetime.now(),
            status=SessionStatus.RECORDING,
        )
        
        # Create session directory
        session_dir = self._current_project_path / "_capture" / session_id
        session_dir.mkdir(parents=True, exist_ok=True)
        
        self.current_session = session
        self._save_session()
        
        return session
    
    def get_session_dir(self) -> Path:
        """Get current session directory."""
        if not self.current_session or not self._current_project_path:
            raise RuntimeError("No active session")
        return self._current_project_path / "_capture" / self.current_session.id
    
    def get_video_path(self) -> Path:
        """Get path for video file."""
        return self.get_session_dir() / self.current_session.video_file
    
    def update_status(self, status: SessionStatus) -> None:
        """Update session status."""
        if self.current_session:
            self.current_session.status = status
            self._save_session()
    
    def set_duration(self, duration: float) -> None:
        """Set recording duration."""
        if self.current_session:
            self.current_session.duration = duration
            self._save_session()
    
    def set_transcript(self, transcript_file: str) -> None:
        """Set transcript file name."""
        if self.current_session:
            self.current_session.transcript_file = transcript_file
            self._save_session()
    
    def end_session(self) -> Session:
        """End current session."""
        if not self.current_session:
            raise RuntimeError("No active session")
        
        self.current_session.status = SessionStatus.READY
        self._save_session()
        
        session = self.current_session
        self.current_session = None
        self._current_project_path = None
        
        return session
    
    def cancel_session(self) -> None:
        """Cancel session and delete files."""
        if self.current_session:
            import shutil
            session_dir = self.get_session_dir()
            if session_dir.exists():
                shutil.rmtree(session_dir)
        
        self.current_session = None
        self._current_project_path = None
    
    def list_sessions(self, project: Optional[str] = None) -> List[Session]:
        """List sessions for a project or all projects."""
        sessions = []
        
        if project:
            capture_dir = self.get_project_path(project) / "_capture"
            if capture_dir.exists():
                for session_dir in sorted(capture_dir.iterdir(), reverse=True):
                    if session_dir.is_dir():
                        session_file = session_dir / "session.json"
                        if session_file.exists():
                            try:
                                with open(session_file) as f:
                                    sessions.append(Session.from_dict(json.load(f)))
                            except:
                                pass
        else:
            for proj in self.list_projects():
                sessions.extend(self.list_sessions(proj))
            sessions.sort(key=lambda s: s.created_at, reverse=True)
        
        return sessions
    
    def _save_session(self) -> None:
        """Save current session to disk."""
        if not self.current_session:
            return
        
        session_file = self.get_session_dir() / "session.json"
        with open(session_file, "w") as f:
            json.dump(self.current_session.to_dict(), f, indent=2)