"""
SQLite database for recordings, transcripts, and highlights.
"""

import sqlite3
from contextlib import contextmanager
from datetime import datetime
from pathlib import Path
from typing import Optional

import config

# Schema version for migrations
SCHEMA_VERSION = 2


def get_connection() -> sqlite3.Connection:
    """Get a database connection with row factory."""
    conn = sqlite3.connect(str(config.DATABASE_PATH))
    conn.row_factory = sqlite3.Row
    conn.execute("PRAGMA foreign_keys = ON")
    return conn


@contextmanager
def get_db():
    """Context manager for database connections."""
    conn = get_connection()
    try:
        yield conn
        conn.commit()
    except Exception:
        conn.rollback()
        raise
    finally:
        conn.close()


def init_db():
    """Initialize database schema."""
    with get_db() as conn:
        conn.executescript("""
            -- Recordings table
            CREATE TABLE IF NOT EXISTS recordings (
                id INTEGER PRIMARY KEY AUTOINCREMENT,
                source_name TEXT NOT NULL DEFAULT 'phone',
                source_file TEXT UNIQUE NOT NULL,
                audio_path TEXT,
                filename TEXT NOT NULL,
                duration REAL,
                language TEXT,
                language_probability REAL,
                sample_rate INTEGER,
                bit_depth INTEGER,
                file_size_bytes INTEGER,
                recorded_at TIMESTAMP,
                imported_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
                transcribed_at TIMESTAMP
            );

            -- Transcript segments
            CREATE TABLE IF NOT EXISTS segments (
                id INTEGER PRIMARY KEY AUTOINCREMENT,
                recording_id INTEGER NOT NULL,
                start_time REAL NOT NULL,
                end_time REAL NOT NULL,
                text TEXT NOT NULL,
                confidence REAL,
                FOREIGN KEY (recording_id) REFERENCES recordings(id) ON DELETE CASCADE
            );

            -- User highlights/bookmarks
            CREATE TABLE IF NOT EXISTS highlights (
                id INTEGER PRIMARY KEY AUTOINCREMENT,
                recording_id INTEGER NOT NULL,
                segment_id INTEGER,
                start_seconds REAL NOT NULL,
                end_seconds REAL,
                tag TEXT NOT NULL DEFAULT 'important',
                note TEXT,
                created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
                FOREIGN KEY (recording_id) REFERENCES recordings(id) ON DELETE CASCADE,
                FOREIGN KEY (segment_id) REFERENCES segments(id) ON DELETE SET NULL
            );

            -- Indexes
            CREATE INDEX IF NOT EXISTS idx_recordings_source ON recordings(source_name);
            CREATE INDEX IF NOT EXISTS idx_recordings_recorded_at ON recordings(recorded_at);
            CREATE INDEX IF NOT EXISTS idx_segments_recording ON segments(recording_id);
            CREATE INDEX IF NOT EXISTS idx_highlights_recording ON highlights(recording_id);

            -- Schema version tracking
            CREATE TABLE IF NOT EXISTS schema_version (
                version INTEGER PRIMARY KEY
            );
        """)

        # Check/set schema version and run migrations
        cur = conn.execute("SELECT version FROM schema_version LIMIT 1")
        row = cur.fetchone()
        if row is None:
            conn.execute("INSERT INTO schema_version (version) VALUES (?)", (SCHEMA_VERSION,))
        else:
            current_version = row[0]
            # Migration v1 -> v2: add end_seconds to highlights
            if current_version < 2:
                try:
                    conn.execute("ALTER TABLE highlights ADD COLUMN end_seconds REAL")
                except sqlite3.OperationalError:
                    pass  # Column already exists
                conn.execute("UPDATE schema_version SET version = 2")


# Recording operations

def get_recording_by_source_file(source_file: str) -> Optional[dict]:
    """Get recording by source file path (for idempotent import)."""
    with get_db() as conn:
        cur = conn.execute(
            "SELECT * FROM recordings WHERE source_file = ?",
            (source_file,)
        )
        row = cur.fetchone()
        return dict(row) if row else None


def get_recording_by_source_file(source_file: str) -> Optional[dict]:
    """Get a recording by its source file name."""
    with get_db() as conn:
        cur = conn.execute(
            "SELECT * FROM recordings WHERE source_file = ?",
            (source_file,)
        )
        row = cur.fetchone()
        return dict(row) if row else None


def create_recording(
    source_file: str,
    filename: str,
    source_name: str = "phone",
    audio_path: Optional[str] = None,
    duration: Optional[float] = None,
    language: Optional[str] = None,
    language_probability: Optional[float] = None,
    recorded_at: Optional[datetime] = None,
    transcribed_at: Optional[datetime] = None,
) -> int:
    """Create a new recording entry. Returns the recording ID."""
    with get_db() as conn:
        cur = conn.execute(
            """
            INSERT INTO recordings
            (source_file, filename, source_name, audio_path, duration, language,
             language_probability, recorded_at, transcribed_at)
            VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?)
            """,
            (source_file, filename, source_name, audio_path, duration, language,
             language_probability, recorded_at, transcribed_at)
        )
        return cur.lastrowid


def update_recording(recording_id: int, **kwargs) -> bool:
    """Update recording fields."""
    if not kwargs:
        return False

    allowed_fields = {
        'audio_path', 'duration', 'language', 'language_probability',
        'sample_rate', 'bit_depth', 'file_size_bytes', 'transcribed_at'
    }
    fields = {k: v for k, v in kwargs.items() if k in allowed_fields}

    if not fields:
        return False

    set_clause = ", ".join(f"{k} = ?" for k in fields.keys())
    values = list(fields.values()) + [recording_id]

    with get_db() as conn:
        conn.execute(
            f"UPDATE recordings SET {set_clause} WHERE id = ?",
            values
        )
        return True


def get_recording(recording_id: int) -> Optional[dict]:
    """Get recording by ID with segments."""
    with get_db() as conn:
        cur = conn.execute("SELECT * FROM recordings WHERE id = ?", (recording_id,))
        row = cur.fetchone()
        if not row:
            return None

        recording = dict(row)

        # Get segments
        cur = conn.execute(
            "SELECT * FROM segments WHERE recording_id = ? ORDER BY start_time",
            (recording_id,)
        )
        recording['segments'] = [dict(r) for r in cur.fetchall()]

        # Get highlights
        cur = conn.execute(
            "SELECT * FROM highlights WHERE recording_id = ? ORDER BY start_seconds",
            (recording_id,)
        )
        recording['highlights'] = [dict(r) for r in cur.fetchall()]

        return recording


def list_recordings(
    source_name: Optional[str] = None,
    date_from: Optional[str] = None,
    date_to: Optional[str] = None,
    limit: int = 100,
    offset: int = 0,
) -> list[dict]:
    """List recordings with optional filters."""
    query = "SELECT * FROM recordings WHERE 1=1"
    params = []

    if source_name:
        query += " AND source_name = ?"
        params.append(source_name)

    if date_from:
        query += " AND recorded_at >= ?"
        params.append(date_from)

    if date_to:
        query += " AND recorded_at <= ?"
        params.append(date_to)

    query += " ORDER BY recorded_at DESC LIMIT ? OFFSET ?"
    params.extend([limit, offset])

    with get_db() as conn:
        cur = conn.execute(query, params)
        return [dict(r) for r in cur.fetchall()]


def get_recordings_count(source_name: Optional[str] = None) -> int:
    """Get total count of recordings."""
    query = "SELECT COUNT(*) FROM recordings"
    params = []

    if source_name:
        query += " WHERE source_name = ?"
        params.append(source_name)

    with get_db() as conn:
        cur = conn.execute(query, params)
        return cur.fetchone()[0]


# Segment operations

def create_segments(recording_id: int, segments: list[dict]) -> int:
    """Bulk create segments for a recording. Returns count created."""
    if not segments:
        return 0

    with get_db() as conn:
        conn.executemany(
            """
            INSERT INTO segments (recording_id, start_time, end_time, text, confidence)
            VALUES (?, ?, ?, ?, ?)
            """,
            [
                (recording_id, s['start'], s['end'], s['text'], s.get('confidence'))
                for s in segments
            ]
        )
        return len(segments)


def delete_segments(recording_id: int) -> int:
    """Delete all segments for a recording. Returns count deleted."""
    with get_db() as conn:
        cur = conn.execute(
            "DELETE FROM segments WHERE recording_id = ?",
            (recording_id,)
        )
        return cur.rowcount


# Highlight operations

def create_highlight(
    recording_id: int,
    start_seconds: float,
    end_seconds: Optional[float] = None,
    tag: str = "important",
    note: Optional[str] = None,
    segment_id: Optional[int] = None,
) -> int:
    """Create a highlight. Returns the highlight ID."""
    with get_db() as conn:
        cur = conn.execute(
            """
            INSERT INTO highlights (recording_id, segment_id, start_seconds, end_seconds, tag, note)
            VALUES (?, ?, ?, ?, ?, ?)
            """,
            (recording_id, segment_id, start_seconds, end_seconds, tag, note)
        )
        return cur.lastrowid


def delete_highlight(highlight_id: int) -> bool:
    """Delete a highlight."""
    with get_db() as conn:
        cur = conn.execute("DELETE FROM highlights WHERE id = ?", (highlight_id,))
        return cur.rowcount > 0


def list_highlights(
    recording_id: Optional[int] = None,
    tag: Optional[str] = None,
    limit: int = 100,
) -> list[dict]:
    """List highlights with optional filters."""
    query = """
        SELECT h.*, r.filename as recording_filename, r.recorded_at
        FROM highlights h
        JOIN recordings r ON h.recording_id = r.id
        WHERE 1=1
    """
    params = []

    if recording_id:
        query += " AND h.recording_id = ?"
        params.append(recording_id)

    if tag:
        query += " AND h.tag = ?"
        params.append(tag)

    query += " ORDER BY h.created_at DESC LIMIT ?"
    params.append(limit)

    with get_db() as conn:
        cur = conn.execute(query, params)
        return [dict(r) for r in cur.fetchall()]


# Source/device operations

def list_sources() -> list[dict]:
    """Get summary of all source names."""
    with get_db() as conn:
        cur = conn.execute("""
            SELECT
                source_name,
                COUNT(*) as recording_count,
                SUM(duration) / 3600.0 as total_hours,
                MAX(recorded_at) as last_recording
            FROM recordings
            GROUP BY source_name
            ORDER BY last_recording DESC
        """)
        return [dict(r) for r in cur.fetchall()]