-- Smoke test: traverse_temporal_window() type-cast fix (PGMNEMO-HOTFIX-2)
-- Verifies ::DOUBLE PRECISION cast and 1-hour window semantics using synthetic values.
-- No live table required.

-- 1. Cast fix: ABS(EXTRACT(EPOCH FROM ...))::DOUBLE PRECISION returns double precision (not numeric)
SELECT ABS(EXTRACT(EPOCH FROM (
    TIMESTAMPTZ '2026-01-01 10:30:00+00' - TIMESTAMPTZ '2026-01-01 10:00:00+00'
)))::DOUBLE PRECISION = 1800.0 AS cast_is_double_precision;

-- 2. Two lessons within 1-hour window yield 2 rows; outside-window lesson excluded (non-empty)
SELECT COUNT(*) = 2 AS two_lessons_in_window
FROM (
    SELECT
        l.id                                                           AS lesson_id,
        ABS(EXTRACT(EPOCH FROM (l.ts - a.ts)))::DOUBLE PRECISION      AS time_delta_sec,
        NULL::DOUBLE PRECISION                                         AS edge_weight,
        (NULL::DOUBLE PRECISION IS NOT NULL)                          AS linked
    FROM (VALUES
        (101::BIGINT, TIMESTAMPTZ '2026-01-01 10:30:00+00'),
        (102::BIGINT, TIMESTAMPTZ '2026-01-01 10:45:00+00'),
        (103::BIGINT, TIMESTAMPTZ '2026-01-01 12:05:00+00')
    ) AS l(id, ts),
    (VALUES (TIMESTAMPTZ '2026-01-01 10:00:00+00')) AS a(ts),
    (VALUES (INTERVAL '1 hour')) AS w(iv)
    WHERE l.ts BETWEEN (a.ts - w.iv) AND (a.ts + w.iv)
) sub;

-- 3. Correct columns: lesson_id BIGINT, time_delta_sec DOUBLE PRECISION, edge_weight DOUBLE PRECISION, linked BOOLEAN
SELECT
    lesson_id,
    time_delta_sec,
    edge_weight,
    linked
FROM (
    SELECT
        101::BIGINT                                                        AS lesson_id,
        ABS(EXTRACT(EPOCH FROM (
            TIMESTAMPTZ '2026-01-01 10:30:00+00' - TIMESTAMPTZ '2026-01-01 10:00:00+00'
        )))::DOUBLE PRECISION                                              AS time_delta_sec,
        NULL::DOUBLE PRECISION                                             AS edge_weight,
        (NULL::DOUBLE PRECISION IS NOT NULL)                              AS linked
) sub;