-- Enable PostGIS extension
CREATE EXTENSION IF NOT EXISTS postgis;

-- API Keys table
CREATE TABLE api_keys (
    id SERIAL PRIMARY KEY,
    key VARCHAR(64) UNIQUE NOT NULL,
    app_name VARCHAR(100) NOT NULL,
    rate_limit INTEGER DEFAULT 1000,
    is_active BOOLEAN DEFAULT true,
    created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
    last_used_at TIMESTAMP
);

-- Routes table (маршруты)
CREATE TABLE routes (
    id SERIAL PRIMARY KEY,
    route_number VARCHAR(10) NOT NULL,
    name VARCHAR(200) NOT NULL,
    type VARCHAR(20) NOT NULL CHECK (type IN ('bus', 'minibus', 'trolleybus', 'tram')),
    color VARCHAR(7) DEFAULT '#0066CC',
    is_active BOOLEAN DEFAULT true,
    description TEXT,
    created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
    updated_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP
);

-- Stops table (остановки) with geospatial support
CREATE TABLE stops (
    id SERIAL PRIMARY KEY,
    name VARCHAR(200) NOT NULL,
    location GEOGRAPHY(Point, 4326) NOT NULL,
    address VARCHAR(300),
    description TEXT,
    is_active BOOLEAN DEFAULT true,
    created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
    updated_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP
);

-- Create spatial index for stops
CREATE INDEX idx_stops_location ON stops USING GIST(location);

-- Route stops junction table (связь маршрутов и остановок)
CREATE TABLE route_stops (
    id SERIAL PRIMARY KEY,
    route_id INTEGER NOT NULL REFERENCES routes(id) ON DELETE CASCADE,
    stop_id INTEGER NOT NULL REFERENCES stops(id) ON DELETE CASCADE,
    sequence INTEGER NOT NULL,
    time_offset_minutes INTEGER NOT NULL DEFAULT 0,
    UNIQUE(route_id, stop_id, sequence)
);

-- Schedules table (расписание)
CREATE TABLE schedules (
    id SERIAL PRIMARY KEY,
    route_id INTEGER NOT NULL REFERENCES routes(id) ON DELETE CASCADE,
    day_type VARCHAR(20) NOT NULL CHECK (day_type IN ('weekday', 'saturday', 'sunday', 'holiday')),
    departure_times TIME[] NOT NULL,
    valid_from DATE,
    valid_until DATE,
    created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
    updated_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP
);

-- Vehicles table (транспортные средства)
CREATE TABLE vehicles (
    id SERIAL PRIMARY KEY,
    vehicle_number VARCHAR(20) NOT NULL,
    registration VARCHAR(20),
    type VARCHAR(20) NOT NULL,
    capacity INTEGER,
    route_id INTEGER REFERENCES routes(id) ON DELETE SET NULL,
    is_active BOOLEAN DEFAULT true,
    created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
    updated_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP
);

-- Historical delays table (статистика задержек)
CREATE TABLE historical_delays (
    id SERIAL PRIMARY KEY,
    route_id INTEGER NOT NULL REFERENCES routes(id) ON DELETE CASCADE,
    stop_id INTEGER NOT NULL REFERENCES stops(id) ON DELETE CASCADE,
    hour_of_day INTEGER NOT NULL CHECK (hour_of_day BETWEEN 0 AND 23),
    day_type VARCHAR(20) NOT NULL,
    avg_delay_minutes INTEGER NOT NULL,
    sample_count INTEGER DEFAULT 1,
    created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
    updated_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
    UNIQUE(route_id, stop_id, hour_of_day, day_type)
);

-- Alerts table (уведомления и оповещения)
CREATE TABLE alerts (
    id SERIAL PRIMARY KEY,
    route_id INTEGER REFERENCES routes(id) ON DELETE CASCADE,
    alert_type VARCHAR(20) NOT NULL CHECK (alert_type IN ('delay', 'cancellation', 'detour', 'info')),
    title VARCHAR(200) NOT NULL,
    message TEXT NOT NULL,
    start_time TIMESTAMP NOT NULL,
    end_time TIMESTAMP,
    is_active BOOLEAN DEFAULT true,
    created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP
);

-- Sync log table (для offline синхронизации)
CREATE TABLE sync_log (
    id SERIAL PRIMARY KEY,
    table_name VARCHAR(50) NOT NULL,
    record_id INTEGER NOT NULL,
    action VARCHAR(20) NOT NULL CHECK (action IN ('insert', 'update', 'delete')),
    timestamp TIMESTAMP DEFAULT CURRENT_TIMESTAMP
);

-- Create indexes
CREATE INDEX idx_routes_number ON routes(route_number);
CREATE INDEX idx_routes_active ON routes(is_active);
CREATE INDEX idx_stops_name ON stops(name);
CREATE INDEX idx_route_stops_route ON route_stops(route_id);
CREATE INDEX idx_route_stops_stop ON route_stops(stop_id);
CREATE INDEX idx_schedules_route ON schedules(route_id);
CREATE INDEX idx_vehicles_route ON vehicles(route_id);
CREATE INDEX idx_alerts_active ON alerts(is_active, start_time, end_time);
CREATE INDEX idx_sync_log_timestamp ON sync_log(timestamp);

-- Create function to update updated_at timestamp
CREATE OR REPLACE FUNCTION update_updated_at_column()
RETURNS TRIGGER AS $$
BEGIN
    NEW.updated_at = CURRENT_TIMESTAMP;
    RETURN NEW;
END;
$$ language 'plpgsql';

-- Create triggers for updated_at
CREATE TRIGGER update_routes_updated_at BEFORE UPDATE ON routes
    FOR EACH ROW EXECUTE FUNCTION update_updated_at_column();
    
CREATE TRIGGER update_stops_updated_at BEFORE UPDATE ON stops
    FOR EACH ROW EXECUTE FUNCTION update_updated_at_column();
    
CREATE TRIGGER update_schedules_updated_at BEFORE UPDATE ON schedules
    FOR EACH ROW EXECUTE FUNCTION update_updated_at_column();
    
CREATE TRIGGER update_vehicles_updated_at BEFORE UPDATE ON vehicles
    FOR EACH ROW EXECUTE FUNCTION update_updated_at_column();

-- Create function to log changes for sync
CREATE OR REPLACE FUNCTION log_sync_changes()
RETURNS TRIGGER AS $$
BEGIN
    IF (TG_OP = 'DELETE') THEN
        INSERT INTO sync_log (table_name, record_id, action)
        VALUES (TG_TABLE_NAME, OLD.id, 'delete');
        RETURN OLD;
    ELSIF (TG_OP = 'UPDATE') THEN
        INSERT INTO sync_log (table_name, record_id, action)
        VALUES (TG_TABLE_NAME, NEW.id, 'update');
        RETURN NEW;
    ELSIF (TG_OP = 'INSERT') THEN
        INSERT INTO sync_log (table_name, record_id, action)
        VALUES (TG_TABLE_NAME, NEW.id, 'insert');
        RETURN NEW;
    END IF;
    RETURN NULL;
END;
$$ LANGUAGE plpgsql;

-- Create sync triggers for main tables
CREATE TRIGGER sync_routes AFTER INSERT OR UPDATE OR DELETE ON routes
    FOR EACH ROW EXECUTE FUNCTION log_sync_changes();
    
CREATE TRIGGER sync_stops AFTER INSERT OR UPDATE OR DELETE ON stops
    FOR EACH ROW EXECUTE FUNCTION log_sync_changes();
    
CREATE TRIGGER sync_route_stops AFTER INSERT OR UPDATE OR DELETE ON route_stops
    FOR EACH ROW EXECUTE FUNCTION log_sync_changes();
    
CREATE TRIGGER sync_schedules AFTER INSERT OR UPDATE OR DELETE ON schedules
    FOR EACH ROW EXECUTE FUNCTION log_sync_changes();

-- Insert sample API key for development
INSERT INTO api_keys (key, app_name, rate_limit) 
VALUES ('dev_key_12345678', 'Development App', 10000);

-- Grant permissions
GRANT ALL PRIVILEGES ON ALL TABLES IN SCHEMA public TO transit_admin;
GRANT ALL PRIVILEGES ON ALL SEQUENCES IN SCHEMA public TO transit_admin;