Fix tide/current classification for subordinate stations

Subordinate stations with different high/low corrections (time offsets
or level multipliers) were incorrectly classified as current stations.

The simple? method checked if high/low corrections were identical,
and current? returned !simple?. This incorrectly assumed that any
asymmetry in corrections meant the station was a current station.

In reality, subordinate tide stations can have different corrections
for high vs low tides. Current stations are identified by having
current-specific data: flood/ebb slack times or direction fields.

Changes:
- Updated current? to check for flood/ebb times or direction data
- Updated tide? to simply return !current?
- Removed dependency on simple? for classification
- Added test for asymmetric tide stations
- Updated existing test to correctly identify current stations

Fixes issue where stations like Meadow Point, Shilshole Bay with
high_time=0min, low_time=-1min were marked as current instead of tide.

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

Author: jpr5

CHANGELOG.md

@@ -5,6 +5,15 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
+## [1.0.1] - 2026-01-20
+
+### Fixed
+
+- Fixed tide/current classification for subordinate stations with asymmetric corrections
+  - Previously, subordinate stations with different high/low time offsets or level multipliers were incorrectly classified as current stations
+  - Now correctly classifies stations based on presence of current-specific indicators (flood/ebb times, direction data)
+  - Subordinate tide stations can have different corrections for high vs low tides and are now properly identified as tide stations
+
 ## [1.0.0] - 2026-01-20
 
 ### Added

lib/tcd/station.rb

@@ -90,19 +90,26 @@ def simple?
 
         # Check if this station has current (not tide) data.
         # Current stations have direction fields and/or flood/ebb slack times.
+        # These are the definitive indicators of current data.
         #
         # @return [Boolean] true if this is a current station
         def current?
-            return false if reference?
-            !simple?
+            # Reference stations with direction data are current stations
+            return true if min_direction || max_direction
+
+            # Subordinate stations with flood/ebb times are current stations
+            return true if flood_begins || ebb_begins
+
+            false
         end
 
         # Check if this station has tide (not current) data.
-        # Tide stations are either reference stations or simple subordinates.
+        # Tide stations do not have current-specific indicators (direction, flood/ebb).
+        # Note: subordinate tide stations may have different high/low corrections.
         #
         # @return [Boolean] true if this is a tide station
         def tide?
-            reference? || simple?
+            !current?
         end
 
         def to_s

lib/tcd/version.rb

@@ -1,5 +1,5 @@
 # frozen_string_literal: true
 
 module TCD
-    VERSION = "1.0.0"
+    VERSION = "1.0.1"
 end

test/tcd_file_test.rb

@@ -278,13 +278,49 @@ def test_simple_and_current_station_types
                 refute simple_sub.current?
             end
 
-            # Find a non-simple subordinate (current station)
-            current_sub = db.subordinate_stations.find { |s| !s.simple? }
+            # Find a non-simple subordinate with different high/low corrections (tide station)
+            # These are tide stations that happen to have asymmetric corrections
+            tide_with_corrections = db.subordinate_stations.find { |s|
+                !s.simple? && s.flood_begins.nil? && s.ebb_begins.nil?
+            }
+            if tide_with_corrections
+                refute tide_with_corrections.simple?
+                assert tide_with_corrections.tide?, "Station with asymmetric corrections but no current data should be tide station"
+                refute tide_with_corrections.current?
+            end
+
+            # Find an actual current station (has flood/ebb or direction data)
+            current_sub = db.subordinate_stations.find { |s|
+                s.flood_begins || s.ebb_begins || s.min_direction || s.max_direction
+            }
             if current_sub
-                refute current_sub.simple?
-                assert current_sub.current?
+                assert current_sub.current?, "Station with flood/ebb/direction data should be current station"
                 refute current_sub.tide?
             end
         end
     end
+
+    # Regression test for tide/current classification bug
+    # Some subordinate stations have different high/low corrections but no current data
+    # These should be classified as tide stations, not current stations
+    def test_subordinate_tide_with_asymmetric_corrections
+        TCD.open(TCD_TEST_FILE) do |db|
+            # Find subordinate stations with different time/level corrections but no current data
+            asymmetric_tides = db.subordinate_stations.select { |s|
+                (s.max_time_add != s.min_time_add ||
+                 s.max_level_multiply != s.min_level_multiply) &&
+                s.flood_begins.nil? &&
+                s.ebb_begins.nil? &&
+                s.min_direction.nil? &&
+                s.max_direction.nil?
+            }
+
+            skip "No asymmetric tide stations in test file" if asymmetric_tides.empty?
+
+            sample = asymmetric_tides.first
+            assert sample.tide?, "#{sample.name} should be tide station (no current indicators)"
+            refute sample.current?, "#{sample.name} should not be current station"
+            refute sample.simple?, "#{sample.name} should not be simple (has asymmetric corrections)"
+        end
+    end
 end