from __future__ import annotations

import sqlite3
from pathlib import Path


SCHEMA = """
CREATE TABLE IF NOT EXISTS users (
    id TEXT PRIMARY KEY,
    user_key TEXT NOT NULL,
    created_at TIMESTAMP NOT NULL,
    updated_at TIMESTAMP NOT NULL
);

CREATE TABLE IF NOT EXISTS user_resources (
    id TEXT PRIMARY KEY,
    user_id TEXT NOT NULL,
    app_id TEXT NOT NULL DEFAULT 'default',
    project_id TEXT NOT NULL DEFAULT 'default',
    session_id TEXT NOT NULL,
    original_filename TEXT,
    mime_type TEXT,
    content_type TEXT NOT NULL,
    uri TEXT NOT NULL,
    uri_public BOOLEAN NOT NULL DEFAULT FALSE,
    sha256 TEXT,
    size_bytes INTEGER,
    title TEXT,
    description TEXT,
    status TEXT NOT NULL DEFAULT 'pending',
    error_message TEXT,
    created_at TIMESTAMP NOT NULL,
    updated_at TIMESTAMP NOT NULL,
    deleted_at TIMESTAMP
);

CREATE INDEX IF NOT EXISTS idx_user_resources_user_scope
ON user_resources (user_id, app_id, project_id, status, deleted_at);

CREATE INDEX IF NOT EXISTS idx_user_resources_session_id
ON user_resources (session_id);

CREATE INDEX IF NOT EXISTS idx_user_resources_user_id
ON user_resources (user_id);

CREATE TABLE IF NOT EXISTS memory_attachments (
    id TEXT PRIMARY KEY,
    user_id TEXT NOT NULL,
    app_id TEXT NOT NULL DEFAULT 'default',
    project_id TEXT NOT NULL DEFAULT 'default',
    session_id TEXT NOT NULL,
    resource_id TEXT,
    content_type TEXT NOT NULL,
    name TEXT NOT NULL,
    internal_uri TEXT NOT NULL,
    source TEXT NOT NULL,
    sha256 TEXT,
    created_at TIMESTAMP NOT NULL,
    deleted_at TIMESTAMP
);

CREATE UNIQUE INDEX IF NOT EXISTS idx_memory_attachments_unique_uri
ON memory_attachments (user_id, session_id, internal_uri);

CREATE INDEX IF NOT EXISTS idx_memory_attachments_user_session
ON memory_attachments (user_id, session_id, deleted_at);

CREATE INDEX IF NOT EXISTS idx_memory_attachments_resource
ON memory_attachments (resource_id, deleted_at);

INSERT OR IGNORE INTO memory_attachments (
    id,
    user_id,
    app_id,
    project_id,
    session_id,
    resource_id,
    content_type,
    name,
    internal_uri,
    source,
    sha256,
    created_at,
    deleted_at
)
SELECT
    'a_resource_' || id,
    user_id,
    app_id,
    project_id,
    session_id,
    id,
    content_type,
    COALESCE(original_filename, id),
    uri,
    'resource_upload',
    sha256,
    created_at,
    deleted_at
FROM user_resources;

CREATE TABLE IF NOT EXISTS memory_tombstones (
    id TEXT PRIMARY KEY,
    user_id TEXT NOT NULL,
    memory_id TEXT,
    session_id TEXT,
    reason TEXT,
    created_at TIMESTAMP NOT NULL
);

CREATE INDEX IF NOT EXISTS idx_memory_tombstones_user_memory
ON memory_tombstones (user_id, memory_id);

CREATE INDEX IF NOT EXISTS idx_memory_tombstones_user_session
ON memory_tombstones (user_id, session_id);

CREATE TABLE IF NOT EXISTS memory_overrides (
    id TEXT PRIMARY KEY,
    user_id TEXT NOT NULL,
    memory_id TEXT,
    session_id TEXT,
    override_text TEXT NOT NULL,
    is_active BOOLEAN NOT NULL DEFAULT TRUE,
    created_at TIMESTAMP NOT NULL,
    updated_at TIMESTAMP NOT NULL
);

CREATE INDEX IF NOT EXISTS idx_memory_overrides_user_memory_active
ON memory_overrides (user_id, memory_id, is_active);
"""


def connect(db_path: Path) -> sqlite3.Connection:
    conn = sqlite3.connect(db_path)
    conn.row_factory = sqlite3.Row
    conn.execute("PRAGMA journal_mode=WAL")
    conn.execute("PRAGMA foreign_keys=ON")
    conn.execute("PRAGMA busy_timeout=5000")
    return conn


def init_db(db_path: Path) -> None:
    db_path.parent.mkdir(parents=True, exist_ok=True)
    with connect(db_path) as conn:
        conn.executescript(SCHEMA)