-- FLOW-TWO fixture — a SECOND export train, identical in shape to TRN-F2-EXP.
--
-- Run AFTER seed-import-corridor.sql and seed-flow2-export-train.sql.
-- Idempotent.
--
-- The multi-train scenarios (TC-13, TC-14, TC-16) need two export trains on one
-- day with the SAME pool structure, so that "which train did this booking land
-- on" is the only variable. A second train with different pools would confound
-- the overflow question with a capacity question.
--
--     35 × NW5 (CNT) + 20 × CW4 (BLK) + 5 × NW6 (FLT) = 60, at KALITY
--
-- Its wagon numbers (WGN-F2Y-*) are distinct from TRN-F2-EXP's (WGN-F2X-*), so
-- the two consists never compete for the same physical stock — a shared wagon
-- pinned by the other train's schedule would make one consist silently short
-- and the overflow arithmetic wrong.
--
-- Length and pull are slack for the same reason as the first train (862.3 m of
-- wagons behind 1000 m locos, ~5700 T behind 12000 T of pull): this suite tests
-- SLOTS and TYPE, and a length rejection would masquerade as a pool rejection.

-- 1. Its own locomotive pair at KALITY.
INSERT INTO freight.locomotives
  (id, code, max_pull_weight_tons, max_train_length_meters,
   overage_tolerance_tons, current_yard_id)
SELECT gen_random_uuid(), v.code, 12000, 1000, 0, y.id
FROM (VALUES ('LOCO-F2Y-A'), ('LOCO-F2Y-B')) AS v(code)
JOIN freight.yards y ON y.code = 'KALITY'
WHERE NOT EXISTS (SELECT 1 FROM freight.locomotives l WHERE l.code = v.code);

UPDATE freight.locomotives
SET max_pull_weight_tons = 12000, max_train_length_meters = 1000,
    overage_tolerance_tons = 0,
    current_yard_id = (SELECT id FROM freight.yards WHERE code = 'KALITY')
WHERE code IN ('LOCO-F2Y-A', 'LOCO-F2Y-B')
  AND (max_pull_weight_tons IS DISTINCT FROM 12000
       OR max_train_length_meters IS DISTINCT FROM 1000
       OR overage_tolerance_tons IS DISTINCT FROM 0);

-- 2. The train.
INSERT INTO freight.trains
  (id, code, train_name, capacity_tons, current_yard_id,
   import_train_number, export_train_number)
SELECT gen_random_uuid(), 'TRN-F2-EXP2', 'E2E Flow-2 Export Three-Pool II', 4200, y.id,
       '9314', '9313'
FROM freight.yards y
WHERE y.code = 'KALITY'
  AND NOT EXISTS (SELECT 1 FROM freight.trains t WHERE t.code = 'TRN-F2-EXP2');

INSERT INTO freight.train_locomotives (id, train_id, locomotive_id, sequence_no)
SELECT gen_random_uuid(), t.id, l.id, v.seq
FROM (VALUES ('LOCO-F2Y-A', 0), ('LOCO-F2Y-B', 1)) AS v(loco_code, seq)
JOIN freight.trains t ON t.code = 'TRN-F2-EXP2'
JOIN freight.locomotives l ON l.code = v.loco_code
WHERE NOT EXISTS (
  SELECT 1 FROM freight.train_locomotives tl
  WHERE tl.train_id = t.id AND tl.locomotive_id = l.id
);

-- 3. Its own three pools of rolling stock at KALITY.
INSERT INTO freight.wagons (id, wagon_number, wagon_type_id, current_yard_id)
SELECT gen_random_uuid(), 'WGN-F2Y-C' || lpad(g::text, 2, '0'), wt.id, y.id
FROM generate_series(1, 35) AS g
JOIN freight.wagon_types wt ON wt.code = 'NW5'
JOIN freight.yards y ON y.code = 'KALITY'
WHERE NOT EXISTS (
  SELECT 1 FROM freight.wagons w
  WHERE w.wagon_number = 'WGN-F2Y-C' || lpad(g::text, 2, '0')
);

INSERT INTO freight.wagons (id, wagon_number, wagon_type_id, current_yard_id)
SELECT gen_random_uuid(), 'WGN-F2Y-B' || lpad(g::text, 2, '0'), wt.id, y.id
FROM generate_series(1, 20) AS g
JOIN freight.wagon_types wt ON wt.code = 'CW4'
JOIN freight.yards y ON y.code = 'KALITY'
WHERE NOT EXISTS (
  SELECT 1 FROM freight.wagons w
  WHERE w.wagon_number = 'WGN-F2Y-B' || lpad(g::text, 2, '0')
);

INSERT INTO freight.wagons (id, wagon_number, wagon_type_id, current_yard_id)
SELECT gen_random_uuid(), 'WGN-F2Y-F' || lpad(g::text, 2, '0'), wt.id, y.id
FROM generate_series(1, 5) AS g
JOIN freight.wagon_types wt ON wt.code = 'NW6'
JOIN freight.yards y ON y.code = 'KALITY'
WHERE NOT EXISTS (
  SELECT 1 FROM freight.wagons w
  WHERE w.wagon_number = 'WGN-F2Y-F' || lpad(g::text, 2, '0')
);

-- 4. Couple all 60, same order as the first train.
UPDATE freight.wagons w
SET train_id = t.id,
    sequence_number = g.seq,
    status = 'ASSIGNED',
    current_yard_id = t.current_yard_id
FROM freight.trains t,
     LATERAL (
       SELECT ('WGN-F2Y-C' || lpad(s::text, 2, '0')) AS num, s AS seq
       FROM generate_series(1, 35) AS s
       UNION ALL
       SELECT ('WGN-F2Y-B' || lpad(s::text, 2, '0')), 35 + s
       FROM generate_series(1, 20) AS s
       UNION ALL
       SELECT ('WGN-F2Y-F' || lpad(s::text, 2, '0')), 55 + s
       FROM generate_series(1, 5) AS s
     ) g
WHERE t.code = 'TRN-F2-EXP2'
  AND w.wagon_number = g.num
  AND (w.train_id IS DISTINCT FROM t.id
       OR w.sequence_number IS DISTINCT FROM g.seq
       OR w.status IS DISTINCT FROM 'ASSIGNED');