initial code

sql/local/21_build_episodes.sql

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+-- Construct episodes across the complete, globally ordered input history.
+-- A gap exactly equal to the configured threshold remains in the same episode.
+
+CREATE OR REPLACE TABLE sequenced_events AS
+WITH with_previous AS (
+    SELECT
+        *,
+        lag(event_ts) OVER (
+            PARTITION BY vehicle_token
+            ORDER BY event_ts, internal_event_id
+        ) AS previous_event_ts
+    FROM clean_events
+),
+with_markers AS (
+    SELECT
+        *,
+        CASE
+            WHEN previous_event_ts IS NULL THEN 1
+            WHEN event_ts - previous_event_ts
+                 > (SELECT episode_gap_days FROM build_config)
+                   * INTERVAL '1 day'
+                THEN 1
+            ELSE 0
+        END AS starts_episode
+    FROM with_previous
+),
+with_episode_number AS (
+    SELECT
+        *,
+        sum(starts_episode) OVER (
+            PARTITION BY vehicle_token
+            ORDER BY event_ts, internal_event_id
+            ROWS BETWEEN UNBOUNDED PRECEDING AND CURRENT ROW
+        ) AS episode_number
+    FROM with_markers
+)
+SELECT
+    *,
+    row_number() OVER (
+        PARTITION BY vehicle_token, episode_number
+        ORDER BY event_ts, internal_event_id
+    ) AS attempt_number,
+    row_number() OVER (
+        PARTITION BY vehicle_token, episode_number
+        ORDER BY event_ts DESC, internal_event_id DESC
+    ) AS reverse_attempt_number
+FROM with_episode_number;
+
+CREATE OR REPLACE TABLE episode_daily_activity AS
+SELECT
+    vehicle_token,
+    episode_number,
+    cast(event_ts AS DATE) AS event_date,
+    count(*) AS events_in_day
+FROM sequenced_events
+GROUP BY vehicle_token, episode_number, cast(event_ts AS DATE);
+
+CREATE OR REPLACE TABLE episode_aggregates AS
+SELECT
+    e.vehicle_token,
+    e.vehicle_bucket,
+    e.episode_number,
+    min(e.event_ts) AS episode_start,
+    max(e.event_ts) AS episode_end,
+    count(*) AS attempt_count,
+    count(e.canonical_outcome) AS labeled_attempt_count,
+    coalesce(bool_or(e.canonical_outcome = 'pass'), false) AS eventually_passed,
+    max(d.events_in_day) AS max_events_in_day,
+    (list(e.observed_make ORDER BY e.event_ts DESC, e.internal_event_id DESC)
+        FILTER (WHERE e.observed_make IS NOT NULL))[1]
+        AS episode_last_observed_make,
+    (list(e.observed_model ORDER BY e.event_ts DESC, e.internal_event_id DESC)
+        FILTER (WHERE e.observed_model IS NOT NULL))[1]
+        AS episode_last_observed_model,
+    (list(e.observed_model_year ORDER BY e.event_ts DESC, e.internal_event_id DESC)
+        FILTER (WHERE e.observed_model_year IS NOT NULL))[1]
+        AS episode_last_observed_model_year
+FROM sequenced_events AS e
+JOIN episode_daily_activity AS d
+  ON d.vehicle_token = e.vehicle_token
+ AND d.episode_number = e.episode_number
+ AND d.event_date = cast(e.event_ts AS DATE)
+GROUP BY e.vehicle_token, e.vehicle_bucket, e.episode_number;
+
+CREATE OR REPLACE TABLE inspection_episodes AS
+SELECT
+    a.vehicle_token,
+    a.vehicle_bucket,
+    a.episode_number,
+    a.episode_start,
+    a.episode_end,
+    f.internal_event_id AS first_internal_event_id,
+    f.source_era,
+    f.public_county,
+    f.canonical_outcome AS first_outcome,
+    f.outcome_label_source AS first_outcome_label_source,
+    f.program_type AS first_program_type,
+    f.test_type AS first_test_type,
+    l.canonical_outcome AS final_outcome,
+    a.attempt_count,
+    a.labeled_attempt_count,
+    a.eventually_passed,
+    a.max_events_in_day,
+    a.episode_last_observed_make,
+    a.episode_last_observed_model,
+    a.episode_last_observed_model_year
+FROM episode_aggregates AS a
+JOIN sequenced_events AS f
+  ON f.vehicle_token = a.vehicle_token
+ AND f.episode_number = a.episode_number
+ AND f.attempt_number = 1
+JOIN sequenced_events AS l
+  ON l.vehicle_token = a.vehicle_token
+ AND l.episode_number = a.episode_number
+ AND l.reverse_attempt_number = 1;