-- ============================================
-- FASE 2.1 - DISPONIBILIDAD DOBLE CAPA (INCREMENTAL)
-- ============================================

-- PASO 1: AGREGAR CAMPOS DE HORARIO A STAFF
DO $$
BEGIN
    IF NOT EXISTS (SELECT 1 FROM information_schema.columns WHERE table_name = 'staff' AND column_name = 'work_hours_start') THEN
        ALTER TABLE staff ADD COLUMN work_hours_start TIME;
        RAISE NOTICE 'Added work_hours_start to staff';
    END IF;

    IF NOT EXISTS (SELECT 1 FROM information_schema.columns WHERE table_name = 'staff' AND column_name = 'work_hours_end') THEN
        ALTER TABLE staff ADD COLUMN work_hours_end TIME;
        RAISE NOTICE 'Added work_hours_end to staff';
    END IF;

    IF NOT EXISTS (SELECT 1 FROM information_schema.columns WHERE table_name = 'staff' AND column_name = 'work_days') THEN
        ALTER TABLE staff ADD COLUMN work_days TEXT DEFAULT 'MON,TUE,WED,THU,FRI,SAT';
        RAISE NOTICE 'Added work_days to staff';
    END IF;

    IF NOT EXISTS (SELECT 1 FROM information_schema.columns WHERE table_name = 'staff' AND column_name = 'is_available_for_booking') THEN
        ALTER TABLE staff ADD COLUMN is_available_for_booking BOOLEAN DEFAULT true;
        RAISE NOTICE 'Added is_available_for_booking to staff';
    END IF;
END
$$;

-- PASO 2: CREAR TABLA STAFF_AVAILABILITY
CREATE TABLE IF NOT EXISTS staff_availability (
    id UUID PRIMARY KEY DEFAULT gen_random_uuid(),
    staff_id UUID NOT NULL REFERENCES staff(id) ON DELETE CASCADE,
    date DATE NOT NULL,
    start_time TIME NOT NULL,
    end_time TIME NOT NULL,
    is_available BOOLEAN DEFAULT true,
    reason VARCHAR(255),
    created_at TIMESTAMPTZ DEFAULT NOW(),
    created_by UUID REFERENCES staff(id) ON DELETE SET NULL,
    updated_at TIMESTAMPTZ DEFAULT NOW(),
    updated_by UUID REFERENCES staff(id) ON DELETE SET NULL,
    UNIQUE(staff_id, date)
);

-- PASO 3: CREAR TABLA GOOGLE_CALENDAR_EVENTS
CREATE TABLE IF NOT EXISTS google_calendar_events (
    id UUID PRIMARY KEY DEFAULT gen_random_uuid(),
    staff_id UUID NOT NULL REFERENCES staff(id) ON DELETE CASCADE,
    google_event_id VARCHAR(255) UNIQUE NOT NULL,
    title VARCHAR(500) NOT NULL,
    description TEXT,
    start_time_utc TIMESTAMPTZ NOT NULL,
    end_time_utc TIMESTAMPTZ NOT NULL,
    is_blocking BOOLEAN DEFAULT false,
    created_at TIMESTAMPTZ DEFAULT NOW(),
    updated_at TIMESTAMPTZ DEFAULT NOW()
);

-- PASO 4: CREAR TABLA BOOKING_BLOCKS
CREATE TABLE IF NOT EXISTS booking_blocks (
    id UUID PRIMARY KEY DEFAULT gen_random_uuid(),
    location_id UUID NOT NULL REFERENCES locations(id) ON DELETE CASCADE,
    resource_id UUID REFERENCES resources(id) ON DELETE CASCADE,
    start_time_utc TIMESTAMPTZ NOT NULL,
    end_time_utc TIMESTAMPTZ NOT NULL,
    reason VARCHAR(500),
    created_by UUID REFERENCES staff(id) ON DELETE SET NULL,
    created_at TIMESTAMPTZ DEFAULT NOW()
);

-- PASO 5: CREAR INDICES
CREATE INDEX IF NOT EXISTS idx_staff_availability_staff_date ON staff_availability(staff_id, date);
CREATE INDEX IF NOT EXISTS idx_staff_availability_date ON staff_availability(date);
CREATE INDEX IF NOT EXISTS idx_google_calendar_staff ON google_calendar_events(staff_id);
CREATE INDEX IF NOT EXISTS idx_google_calendar_time ON google_calendar_events(start_time_utc, end_time_utc);
CREATE INDEX IF NOT EXISTS idx_booking_blocks_location ON booking_blocks(location_id);
CREATE INDEX IF NOT EXISTS idx_booking_blocks_time ON booking_blocks(start_time_utc, end_time_utc);
CREATE INDEX IF NOT EXISTS idx_booking_blocks_resource ON booking_blocks(resource_id);

-- PASO 6: CREAR FUNCION DE VERIFICACION DE HORARIO LABORAL
CREATE OR REPLACE FUNCTION check_staff_work_hours(
    p_staff_id UUID,
    p_start_time_utc TIMESTAMPTZ,
    p_end_time_utc TIMESTAMPTZ
)
RETURNS BOOLEAN AS $$
DECLARE
    v_staff_record RECORD;
    v_start_time TIME;
    v_end_time TIME;
    v_work_days TEXT;
    v_day_of_week INTEGER;
BEGIN
    SELECT * INTO v_staff_record
    FROM staff
    WHERE id = p_staff_id;
    
    IF NOT FOUND THEN
        RETURN false;
    END IF;
    
    IF NOT v_staff_record.is_active THEN
        RETURN false;
    END IF;
    
    IF NOT v_staff_record.is_available_for_booking THEN
        RETURN false;
    END IF;
    
    v_start_time := p_start_time_utc::TIME;
    v_end_time := p_end_time_utc::TIME;
    v_work_days := v_staff_record.work_days;
    
    v_day_of_week := EXTRACT(ISODOW FROM p_start_time_utc);
    
    IF v_work_days IS NULL THEN
        RETURN true;
    END IF;
    
    IF v_day_of_week = 1 AND v_work_days LIKE '%MON%' THEN RETURN true; END IF;
    IF v_day_of_week = 2 AND v_work_days LIKE '%TUE%' THEN RETURN true; END IF;
    IF v_day_of_week = 3 AND v_work_days LIKE '%WED%' THEN RETURN true; END IF;
    IF v_day_of_week = 4 AND v_work_days LIKE '%THU%' THEN RETURN true; END IF;
    IF v_day_of_week = 5 AND v_work_days LIKE '%FRI%' THEN RETURN true; END IF;
    IF v_day_of_week = 6 AND v_work_days LIKE '%SAT%' THEN RETURN true; END IF;
    IF v_day_of_week = 7 AND v_work_days LIKE '%SUN%' THEN RETURN true; END IF;
    
    IF v_start_time < v_staff_record.work_hours_start OR 
       v_end_time > v_staff_record.work_hours_end THEN
        RETURN false;
    END IF;
    
    RETURN true;
END;
$$ LANGUAGE plpgsql SECURITY DEFINER;

-- PASO 7: CREAR FUNCION DE VERIFICACION DE DISPONIBILIDAD DE STAFF
CREATE OR REPLACE FUNCTION check_staff_availability(
    p_staff_id UUID,
    p_start_time_utc TIMESTAMPTZ,
    p_end_time_utc TIMESTAMPTZ,
    p_exclude_booking_id UUID DEFAULT NULL
)
RETURNS BOOLEAN AS $$
DECLARE
    v_is_work_hours BOOLEAN;
    v_has_calendar_conflict BOOLEAN;
    v_has_manual_block BOOLEAN;
BEGIN
    v_is_work_hours := check_staff_work_hours(p_staff_id, p_start_time_utc, p_end_time_utc);
    
    IF NOT v_is_work_hours THEN
        RETURN false;
    END IF;
    
    SELECT EXISTS(
        SELECT 1
        FROM google_calendar_events
        WHERE staff_id = p_staff_id
        AND is_blocking = true
        AND NOT (p_end_time_utc <= start_time_utc OR p_start_time_utc >= end_time_utc)
    ) INTO v_has_calendar_conflict;
    
    IF v_has_calendar_conflict THEN
        RETURN false;
    END IF;
    
    SELECT EXISTS(
        SELECT 1
        FROM bookings
        WHERE staff_id = p_staff_id
        AND status NOT IN ('cancelled', 'no_show')
        AND (p_exclude_booking_id IS NULL OR id != p_exclude_booking_id)
        AND NOT (p_end_time_utc <= start_time_utc OR p_start_time_utc >= end_time_utc)
    ) INTO v_has_manual_block;
    
    IF v_has_manual_block THEN
        RETURN false;
    END IF;
    
    SELECT EXISTS(
        SELECT 1
        FROM staff_availability
        WHERE staff_id = p_staff_id
        AND date = p_start_time_utc::DATE
        AND is_available = false
        AND NOT (p_end_time_utc::TIME <= start_time OR p_start_time_utc::TIME >= end_time)
    ) INTO v_has_manual_block;
    
    IF v_has_manual_block THEN
        RETURN false;
    END IF;
    
    RETURN true;
END;
$$ LANGUAGE plpgsql SECURITY DEFINER;

-- PASO 8: CREAR FUNCION DE VERIFICACION DE DISPONIBILIDAD DE RECURSO
CREATE OR REPLACE FUNCTION check_resource_availability(
    p_resource_id UUID,
    p_start_time_utc TIMESTAMPTZ,
    p_end_time_utc TIMESTAMPTZ,
    p_exclude_booking_id UUID DEFAULT NULL
)
RETURNS BOOLEAN AS $$
BEGIN
    RETURN NOT EXISTS(
        SELECT 1
        FROM bookings
        WHERE resource_id = p_resource_id
        AND status NOT IN ('cancelled', 'no_show')
        AND (p_exclude_booking_id IS NULL OR id != p_exclude_booking_id)
        AND NOT (p_end_time_utc <= start_time_utc OR p_start_time_utc >= end_time_utc)
    );
END;
$$ LANGUAGE plpgsql SECURITY DEFINER;

-- PASO 9: CREAR FUNCION DE VERIFICACION DE BLOQUEOS DE LOCATION
CREATE OR REPLACE FUNCTION check_location_block(
    p_location_id UUID,
    p_start_time_utc TIMESTAMPTZ,
    p_end_time_utc TIMESTAMPTZ
)
RETURNS BOOLEAN AS $$
BEGIN
    RETURN NOT EXISTS(
        SELECT 1
        FROM booking_blocks
        WHERE location_id = p_location_id
        AND NOT (p_end_time_utc <= start_time_utc OR p_start_time_utc >= end_time_utc)
    );
END;
$$ LANGUAGE plpgsql SECURITY DEFINER;

-- PASO 10: CREAR FUNCION PRINCIPAL DE VERIFICACION
CREATE OR REPLACE FUNCTION check_availability(
    p_location_id UUID,
    p_staff_id UUID,
    p_resource_id UUID,
    p_start_time_utc TIMESTAMPTZ,
    p_end_time_utc TIMESTAMPTZ,
    p_exclude_booking_id UUID DEFAULT NULL
)
RETURNS JSONB AS $$
DECLARE
    v_staff_available BOOLEAN;
    v_resource_available BOOLEAN;
    v_location_available BOOLEAN;
    v_available BOOLEAN;
    v_conflict_type VARCHAR(100);
BEGIN
    v_staff_available := check_staff_availability(p_staff_id, p_start_time_utc, p_end_time_utc, p_exclude_booking_id);
    v_resource_available := check_resource_availability(p_resource_id, p_start_time_utc, p_end_time_utc, p_exclude_booking_id);
    v_location_available := NOT check_location_block(p_location_id, p_start_time_utc, p_end_time_utc);
    
    v_available := v_staff_available AND v_resource_available AND v_location_available;
    
    IF NOT v_available THEN
        IF NOT v_staff_available THEN v_conflict_type := 'staff_not_available';
        ELSIF NOT v_resource_available THEN v_conflict_type := 'resource_not_available';
        ELSIF NOT v_location_available THEN v_conflict_type := 'location_blocked';
        END IF;
    END IF;
    
    RETURN jsonb_build_object(
        'available', v_available,
        'staff_available', v_staff_available,
        'resource_available', v_resource_available,
        'location_available', v_location_available,
        'conflict_type', v_conflict_type
    );
END;
$$ LANGUAGE plpgsql SECURITY DEFINER;

-- PASO 11: CREAR FUNCION PARA OBTENER STAFF DISPONIBLE
CREATE OR REPLACE FUNCTION get_available_staff(
    p_location_id UUID,
    p_start_time_utc TIMESTAMPTZ,
    p_end_time_utc TIMESTAMPTZ,
    p_service_id UUID DEFAULT NULL,
    p_exclude_booking_id UUID DEFAULT NULL
)
RETURNS TABLE (
    staff_id UUID,
    staff_name VARCHAR,
    role VARCHAR,
    work_hours_start TIME,
    work_hours_end TIME,
    work_days TEXT
) AS $$
BEGIN
    RETURN QUERY
    SELECT 
        s.id,
        s.display_name,
        s.role,
        s.work_hours_start,
        s.work_hours_end,
        s.work_days
    FROM staff s
    WHERE s.location_id = p_location_id
    AND s.is_active = true
    AND s.is_available_for_booking = true
    AND s.role IN ('artist', 'staff', 'manager')
    AND check_staff_availability(s.id, p_start_time_utc, p_end_time_utc, p_exclude_booking_id)
    ORDER BY 
        CASE s.role
            WHEN 'manager' THEN 1
            WHEN 'staff' THEN 2
            WHEN 'artist' THEN 3
        END;
END;
$$ LANGUAGE plpgsql SECURITY DEFINER;

-- PASO 12: CREAR FUNCION PARA OBTENER DISPONIBILIDAD DETALLADA
CREATE OR REPLACE FUNCTION get_detailed_availability(
    p_location_id UUID,
    p_service_id UUID,
    p_date DATE,
    p_time_slot_duration_minutes INTEGER DEFAULT 60
)
RETURNS JSONB AS $$
DECLARE
    v_service_duration INTEGER;
    v_start_time TIME := '09:00'::TIME;
    v_end_time TIME := '21:00'::TIME;
    v_time_slots JSONB;
    v_slot_time TIMESTAMPTZ;
    v_slot_end TIMESTAMPTZ;
    v_count INTEGER;
BEGIN
    SELECT duration_minutes INTO v_service_duration
    FROM services
    WHERE id = p_service_id;
    
    IF v_service_duration IS NULL THEN
        v_service_duration := p_time_slot_duration_minutes;
    END IF;
    
    FOR v_count IN 0..((EXTRACT(HOUR FROM v_end_time - v_start_time) * 60 + EXTRACT(MINUTE FROM v_end_time - v_start_time)) / v_service_duration LOOP
        v_slot_time := p_date::TIMESTAMPTZ + v_start_time + (v_count * v_service_duration || ' minutes')::INTERVAL;
        v_slot_end := v_slot_time + v_service_duration || ' minutes'::INTERVAL;
        
        SELECT jsonb_agg(
            jsonb_build_object(
                'start_time', v_slot_time,
                'end_time', v_slot_end,
                'available_staff', (
                    SELECT jsonb_agg(
                        jsonb_build_object(
                            'staff_id', s.id,
                            'name', s.display_name,
                            'role', s.role
                        )
                    )
                    FROM staff s
                    WHERE s.location_id = p_location_id
                    AND s.is_active = true
                    AND s.is_available_for_booking = true
                    AND s.role IN ('artist', 'staff', 'manager')
                    AND check_staff_availability(s.id, v_slot_time, v_slot_end)
                )
            )
        ) INTO v_time_slots
        FROM staff
        LIMIT 1;
    END LOOP;