Constant SCHEMA_SQL 

pub const SCHEMA_SQL: &str = "
-- Sessions table
CREATE TABLE IF NOT EXISTS sessions (
    id TEXT PRIMARY KEY,
    created_at TIMESTAMP NOT NULL,
    last_accessed TIMESTAMP NOT NULL,
    metadata TEXT NOT NULL
);

-- Messages table
CREATE TABLE IF NOT EXISTS messages (
    id INTEGER PRIMARY KEY AUTOINCREMENT,
    session_id TEXT NOT NULL,
    message_index INTEGER NOT NULL,
    role TEXT NOT NULL,
    content TEXT NOT NULL,
    tokens INTEGER NOT NULL,
    timestamp TIMESTAMP NOT NULL,
    importance_score REAL NOT NULL DEFAULT 0.5,
    embedding_generated BOOLEAN NOT NULL DEFAULT FALSE,
    FOREIGN KEY (session_id) REFERENCES sessions(id) ON DELETE CASCADE,
    UNIQUE(session_id, message_index)
);

-- Summaries table
CREATE TABLE IF NOT EXISTS summaries (
    id INTEGER PRIMARY KEY AUTOINCREMENT,
    session_id TEXT NOT NULL,
    message_range_start INTEGER NOT NULL,
    message_range_end INTEGER NOT NULL,
    summary_text TEXT NOT NULL,
    compression_ratio REAL NOT NULL,
    key_topics TEXT NOT NULL,
    generated_at TIMESTAMP NOT NULL,
    FOREIGN KEY (session_id) REFERENCES sessions(id) ON DELETE CASCADE,
    UNIQUE(session_id, message_range_start, message_range_end)
);

-- Details table
CREATE TABLE IF NOT EXISTS details (
    id INTEGER PRIMARY KEY AUTOINCREMENT,
    session_id TEXT NOT NULL,
    message_id INTEGER NOT NULL,
    detail_type TEXT NOT NULL,
    content TEXT NOT NULL,
    context TEXT NOT NULL,
    importance_score REAL NOT NULL,
    accessed_count INTEGER NOT NULL DEFAULT 0,
    last_accessed TIMESTAMP NOT NULL,
    FOREIGN KEY (session_id) REFERENCES sessions(id) ON DELETE CASCADE,
    FOREIGN KEY (message_id) REFERENCES messages(id) ON DELETE CASCADE
);

-- Embeddings table
CREATE TABLE IF NOT EXISTS embeddings (
    id INTEGER PRIMARY KEY AUTOINCREMENT,
    message_id INTEGER NOT NULL,
    embedding BLOB NOT NULL,
    embedding_model TEXT NOT NULL,
    generated_at TIMESTAMP NOT NULL,
    FOREIGN KEY (message_id) REFERENCES messages(id) ON DELETE CASCADE,
    UNIQUE(message_id, embedding_model)
);

-- Indexes for performance
CREATE INDEX IF NOT EXISTS idx_messages_session ON messages (session_id);
CREATE INDEX IF NOT EXISTS idx_messages_timestamp ON messages (timestamp);
CREATE INDEX IF NOT EXISTS idx_summaries_session ON summaries (session_id);
CREATE INDEX IF NOT EXISTS idx_details_session ON details (session_id);
CREATE INDEX IF NOT EXISTS idx_details_type ON details (detail_type);
CREATE INDEX IF NOT EXISTS idx_embeddings_message ON embeddings (message_id);
";

SQL statements for table creation