-- Migration: Add kandang management
-- Date: 2026-02-26
-- Description: Adds kandangs table, kandang_cycles junction table, and kandang_id to mortality_records
-- Also auto-assigns existing mortality records to a default "Kandang 1"

-- 1. Create kandangs table
CREATE TABLE IF NOT EXISTS kandangs (
    id SERIAL PRIMARY KEY,
    name VARCHAR(255) NOT NULL,
    created_at TIMESTAMP WITH TIME ZONE DEFAULT CURRENT_TIMESTAMP,
    updated_at TIMESTAMP WITH TIME ZONE DEFAULT CURRENT_TIMESTAMP
);

-- 2. Create kandang_cycles junction table (doc_in_count per kandang per cycle)
CREATE TABLE IF NOT EXISTS kandang_cycles (
    id SERIAL PRIMARY KEY,
    kandang_id INTEGER NOT NULL,
    cycle_id VARCHAR(255) NOT NULL,
    doc_in_count INTEGER NOT NULL DEFAULT 0,
    created_at TIMESTAMP WITH TIME ZONE DEFAULT CURRENT_TIMESTAMP,
    updated_at TIMESTAMP WITH TIME ZONE DEFAULT CURRENT_TIMESTAMP,
    FOREIGN KEY (kandang_id) REFERENCES kandangs(id) ON DELETE CASCADE,
    FOREIGN KEY (cycle_id) REFERENCES cycles(id) ON DELETE CASCADE,
    UNIQUE(kandang_id, cycle_id)
);

-- 3. Add kandang_id column to mortality_records (nullable for backward compat)
ALTER TABLE mortality_records
ADD COLUMN IF NOT EXISTS kandang_id INTEGER REFERENCES kandangs(id) ON DELETE SET NULL;

-- 4. Add indexes
CREATE INDEX IF NOT EXISTS idx_mortality_kandang_id ON mortality_records(kandang_id);
CREATE INDEX IF NOT EXISTS idx_kandang_cycles_kandang ON kandang_cycles(kandang_id);
CREATE INDEX IF NOT EXISTS idx_kandang_cycles_cycle ON kandang_cycles(cycle_id);

-- 5. Add updated_at triggers
DROP TRIGGER IF EXISTS update_kandangs_updated_at ON kandangs;
CREATE TRIGGER update_kandangs_updated_at BEFORE UPDATE ON kandangs
    FOR EACH ROW EXECUTE FUNCTION update_updated_at_column();

DROP TRIGGER IF EXISTS update_kandang_cycles_updated_at ON kandang_cycles;
CREATE TRIGGER update_kandang_cycles_updated_at BEFORE UPDATE ON kandang_cycles
    FOR EACH ROW EXECUTE FUNCTION update_updated_at_column();

-- 6. Auto-assign existing data: Create default "Kandang 1" if not exists and assign all unassigned mortality records
-- Insert default kandang (only if no kandangs exist yet)
INSERT INTO kandangs (name)
SELECT 'Kandang 1'
WHERE NOT EXISTS (SELECT 1 FROM kandangs LIMIT 1);

-- Assign existing mortality records to the first kandang (only records with NULL kandang_id)
UPDATE mortality_records
SET kandang_id = (SELECT id FROM kandangs ORDER BY id LIMIT 1)
WHERE kandang_id IS NULL
AND EXISTS (SELECT 1 FROM kandangs LIMIT 1);

-- Create kandang_cycles entries for the default kandang for all cycles that have doc_in_count
INSERT INTO kandang_cycles (kandang_id, cycle_id, doc_in_count)
SELECT k.id, c.id, COALESCE(c.doc_in_count, 0)
FROM kandangs k, cycles c
WHERE k.id = (SELECT id FROM kandangs ORDER BY id LIMIT 1)
AND NOT EXISTS (
    SELECT 1 FROM kandang_cycles kc
    WHERE kc.kandang_id = k.id AND kc.cycle_id = c.id
);

-- 7. Drop old unique constraint and add new one that includes kandang_id
-- Note: The constraint name follows PostgreSQL naming convention
ALTER TABLE mortality_records DROP CONSTRAINT IF EXISTS mortality_records_cycle_id_day_key;

-- Create new unique index that handles kandang_id (using COALESCE for NULL safety)
DROP INDEX IF EXISTS idx_mortality_cycle_day_kandang;
CREATE UNIQUE INDEX idx_mortality_cycle_day_kandang
ON mortality_records(cycle_id, day, COALESCE(kandang_id, -1));