-- Unified Phase Executions Table
-- This migration replaces the separate phase tables (soaking, airdrying, cracking, shelling)
-- with a unified table that properly supports repetitions

-- =============================================
-- 1. CREATE UNIFIED PHASE EXECUTIONS TABLE
-- =============================================

CREATE TABLE IF NOT EXISTS public.experiment_phase_executions (
    id UUID PRIMARY KEY DEFAULT uuid_generate_v4(),
    repetition_id UUID NOT NULL REFERENCES public.experiment_repetitions(id) ON DELETE CASCADE,
    phase_type TEXT NOT NULL CHECK (phase_type IN ('soaking', 'airdrying', 'cracking', 'shelling')),
    
    -- Scheduling fields (common to all phases)
    scheduled_start_time TIMESTAMP WITH TIME ZONE NOT NULL,
    scheduled_end_time TIMESTAMP WITH TIME ZONE,
    actual_start_time TIMESTAMP WITH TIME ZONE,
    actual_end_time TIMESTAMP WITH TIME ZONE,
    
    -- Phase-specific parameters (nullable, only relevant for specific phases)
    -- Soaking
    soaking_duration_minutes INTEGER CHECK (soaking_duration_minutes > 0),
    
    -- Airdrying  
    duration_minutes INTEGER CHECK (duration_minutes > 0),
    
    -- Cracking
    machine_type_id UUID REFERENCES public.machine_types(id),
    
    -- Status tracking
    status TEXT NOT NULL DEFAULT 'pending' 
        CHECK (status IN ('pending', 'scheduled', 'in_progress', 'completed', 'cancelled')),
    
    created_at TIMESTAMP WITH TIME ZONE DEFAULT NOW(),
    updated_at TIMESTAMP WITH TIME ZONE DEFAULT NOW(),
    created_by UUID NOT NULL REFERENCES public.user_profiles(id),
    
    -- Ensure one execution per phase type per repetition
    CONSTRAINT unique_phase_per_repetition UNIQUE (repetition_id, phase_type)
);

-- =============================================
-- 2. INDEXES FOR PERFORMANCE
-- =============================================

CREATE INDEX IF NOT EXISTS idx_phase_executions_repetition_id 
    ON public.experiment_phase_executions(repetition_id);
CREATE INDEX IF NOT EXISTS idx_phase_executions_phase_type 
    ON public.experiment_phase_executions(phase_type);
CREATE INDEX IF NOT EXISTS idx_phase_executions_status 
    ON public.experiment_phase_executions(status);
CREATE INDEX IF NOT EXISTS idx_phase_executions_scheduled_start_time 
    ON public.experiment_phase_executions(scheduled_start_time);
CREATE INDEX IF NOT EXISTS idx_phase_executions_machine_type_id 
    ON public.experiment_phase_executions(machine_type_id);
CREATE INDEX IF NOT EXISTS idx_phase_executions_created_by 
    ON public.experiment_phase_executions(created_by);

-- =============================================
-- 3. FUNCTION: Calculate Sequential Phase Start Times
-- =============================================

CREATE OR REPLACE FUNCTION calculate_sequential_phase_start_time()
RETURNS TRIGGER AS $$
DECLARE
    prev_phase_end_time TIMESTAMP WITH TIME ZONE;
    phase_order TEXT[] := ARRAY['soaking', 'airdrying', 'cracking', 'shelling'];
    current_phase_index INT;
    prev_phase_name TEXT;
BEGIN
    -- Find current phase index in the sequence
    SELECT array_position(phase_order, NEW.phase_type) INTO current_phase_index;
    
    -- If not the first phase, get previous phase's end time from the same repetition
    IF current_phase_index > 1 THEN
        prev_phase_name := phase_order[current_phase_index - 1];
        
        SELECT scheduled_end_time INTO prev_phase_end_time
        FROM public.experiment_phase_executions
        WHERE repetition_id = NEW.repetition_id
          AND phase_type = prev_phase_name
        ORDER BY created_at DESC
        LIMIT 1;
        
        -- If previous phase exists and has an end time, use it as start time
        IF prev_phase_end_time IS NOT NULL THEN
            NEW.scheduled_start_time := prev_phase_end_time;
        END IF;
    END IF;
    
    -- Calculate end time based on duration (for phases with duration)
    IF NEW.phase_type = 'soaking' AND NEW.soaking_duration_minutes IS NOT NULL THEN
        NEW.scheduled_end_time := NEW.scheduled_start_time + 
            (NEW.soaking_duration_minutes || ' minutes')::INTERVAL;
    ELSIF NEW.phase_type = 'airdrying' AND NEW.duration_minutes IS NOT NULL THEN
        NEW.scheduled_end_time := NEW.scheduled_start_time + 
            (NEW.duration_minutes || ' minutes')::INTERVAL;
    END IF;
    
    RETURN NEW;
END;
$$ LANGUAGE plpgsql;

-- =============================================
-- 4. FUNCTION: Auto-create Phase Executions for New Repetition
-- =============================================

CREATE OR REPLACE FUNCTION create_phase_executions_for_repetition()
RETURNS TRIGGER AS $$
DECLARE
    exp_phase_config RECORD;
    phase_type_list TEXT[] := ARRAY[]::TEXT[];
    phase_name TEXT;
BEGIN
    -- Get experiment phase configuration
    -- Note: Phase durations may need to be set later when scheduling
    SELECT 
        ep.has_soaking,
        ep.has_airdrying,
        ep.has_cracking,
        ep.has_shelling,
        ep.cracking_machine_type_id
    INTO exp_phase_config
    FROM public.experiments e
    JOIN public.experiment_phases ep ON e.phase_id = ep.id
    WHERE e.id = NEW.experiment_id;
    
    -- Build list of phases to create based on experiment configuration
    IF exp_phase_config.has_soaking THEN
        phase_type_list := array_append(phase_type_list, 'soaking');
    END IF;
    IF exp_phase_config.has_airdrying THEN
        phase_type_list := array_append(phase_type_list, 'airdrying');
    END IF;
    IF exp_phase_config.has_cracking THEN
        phase_type_list := array_append(phase_type_list, 'cracking');
    END IF;
    IF exp_phase_config.has_shelling THEN
        phase_type_list := array_append(phase_type_list, 'shelling');
    END IF;
    
    -- Create phase executions for each required phase
    FOREACH phase_name IN ARRAY phase_type_list
    LOOP
        INSERT INTO public.experiment_phase_executions (
            repetition_id,
            phase_type,
            scheduled_start_time,
            status,
            created_by,
            -- Phase-specific parameters
            soaking_duration_minutes,
            duration_minutes,
            machine_type_id
        )
        VALUES (
            NEW.id,
            phase_name,
            NOW(), -- Default start time, will be updated when scheduled or by sequential calculation
            'pending',
            NEW.created_by,
            -- Set phase-specific parameters
            -- Note: Durations will be set when the repetition is scheduled
            -- These can be NULL initially and updated later
            NULL, -- soaking_duration_minutes (set when scheduled)
            NULL, -- duration_minutes (set when scheduled)
            CASE WHEN phase_name = 'cracking' 
                 THEN exp_phase_config.cracking_machine_type_id 
                 ELSE NULL END
        );
    END LOOP;
    
    RETURN NEW;
END;
$$ LANGUAGE plpgsql;

-- =============================================
-- 5. TRIGGERS
-- =============================================

-- Trigger to automatically calculate sequential times and durations
CREATE TRIGGER trigger_calculate_sequential_phase_times
    BEFORE INSERT OR UPDATE ON public.experiment_phase_executions
    FOR EACH ROW
    EXECUTE FUNCTION calculate_sequential_phase_start_time();

-- Trigger to auto-create phases when repetition is created
CREATE TRIGGER trigger_create_phase_executions
    AFTER INSERT ON public.experiment_repetitions
    FOR EACH ROW
    EXECUTE FUNCTION create_phase_executions_for_repetition();

-- Trigger for updated_at
CREATE TRIGGER set_updated_at_phase_executions
    BEFORE UPDATE ON public.experiment_phase_executions
    FOR EACH ROW
    EXECUTE FUNCTION public.handle_updated_at();

-- =============================================
-- 6. CREATE VIEWS FOR PHASE-SPECIFIC ACCESS (Backward Compatibility)
-- =============================================

-- These views allow existing code to work with phase-specific "tables"
CREATE OR REPLACE VIEW public.soaking_view AS
SELECT 
    id,
    (SELECT experiment_id FROM experiment_repetitions WHERE id = repetition_id) as experiment_id,
    repetition_id,
    scheduled_start_time,
    actual_start_time,
    soaking_duration_minutes,
    scheduled_end_time,
    actual_end_time,
    created_at,
    updated_at,
    created_by
FROM public.experiment_phase_executions
WHERE phase_type = 'soaking';

CREATE OR REPLACE VIEW public.airdrying_view AS
SELECT 
    id,
    (SELECT experiment_id FROM experiment_repetitions WHERE id = repetition_id) as experiment_id,
    repetition_id,
    scheduled_start_time,
    actual_start_time,
    duration_minutes,
    scheduled_end_time,
    actual_end_time,
    created_at,
    updated_at,
    created_by
FROM public.experiment_phase_executions
WHERE phase_type = 'airdrying';

CREATE OR REPLACE VIEW public.cracking_view AS
SELECT 
    id,
    (SELECT experiment_id FROM experiment_repetitions WHERE id = repetition_id) as experiment_id,
    repetition_id,
    machine_type_id,
    scheduled_start_time,
    actual_start_time,
    actual_end_time,
    created_at,
    updated_at,
    created_by
FROM public.experiment_phase_executions
WHERE phase_type = 'cracking';

CREATE OR REPLACE VIEW public.shelling_view AS
SELECT 
    id,
    (SELECT experiment_id FROM experiment_repetitions WHERE id = repetition_id) as experiment_id,
    repetition_id,
    scheduled_start_time,
    actual_start_time,
    actual_end_time,
    created_at,
    updated_at,
    created_by
FROM public.experiment_phase_executions
WHERE phase_type = 'shelling';

-- =============================================
-- 7. GRANT PERMISSIONS
-- =============================================

GRANT ALL ON public.experiment_phase_executions TO authenticated;
GRANT SELECT ON public.soaking_view TO authenticated;
GRANT SELECT ON public.airdrying_view TO authenticated;
GRANT SELECT ON public.cracking_view TO authenticated;
GRANT SELECT ON public.shelling_view TO authenticated;

-- =============================================
-- 8. ENABLE ROW LEVEL SECURITY
-- =============================================

ALTER TABLE public.experiment_phase_executions ENABLE ROW LEVEL SECURITY;

-- =============================================
-- 9. CREATE RLS POLICIES
-- =============================================

CREATE POLICY "Phase executions are viewable by authenticated users" 
    ON public.experiment_phase_executions
    FOR SELECT USING (auth.role() = 'authenticated');

CREATE POLICY "Phase executions are insertable by authenticated users" 
    ON public.experiment_phase_executions
    FOR INSERT WITH CHECK (auth.role() = 'authenticated');

CREATE POLICY "Phase executions are updatable by authenticated users" 
    ON public.experiment_phase_executions
    FOR UPDATE USING (auth.role() = 'authenticated');

CREATE POLICY "Phase executions are deletable by authenticated users" 
    ON public.experiment_phase_executions
    FOR DELETE USING (auth.role() = 'authenticated');