Clean up electrification columns and SQL functions (#88)

With the power of lua's multi-return, the SQL functions to calculate
electrification fields are not needed anymore.

import/openrailwaymap.lua

@@ -44,24 +44,18 @@ local railway_line = osm2pgsql.define_table({
     { column = 'maxspeed_forward', type = 'text' },
     { column = 'maxspeed_backward', type = 'text' },
     { column = 'preferred_direction', type = 'text' },
-    { column = 'electrified', type = 'text' },
-    { column = 'deelectrified', type = 'text' },
-    { column = 'frequency', type = 'text' },
-    { column = 'voltage', type = 'text' },
+    { column = 'frequency', type = 'real' },
+    { column = 'voltage', type = 'integer' },
+    { column = 'electrification_state', type = 'text' },
+    { column = 'future_frequency', type = 'real' },
+    { column = 'future_voltage', type = 'integer' },
     { column = 'gauge', type = 'text' },
     { column = 'construction_railway', type = 'text' },
-    { column = 'construction_electrified', type = 'text' },
-    { column = 'construction_frequency', type = 'text' },
-    { column = 'construction_voltage', type = 'text' },
     { column = 'construction_gauge', type = 'text' },
     { column = 'proposed_railway', type = 'text' },
-    { column = 'proposed_electrified', type = 'text' },
-    { column = 'proposed_frequency', type = 'text' },
-    { column = 'proposed_voltage', type = 'text' },
     { column = 'disused_railway', type = 'text' },
     { column = 'abandoned_railway', type = 'text' },
     { column = 'abandoned_name', type = 'text' },
-    { column = 'abandoned_electrified', type = 'text' },
     { column = 'razed_railway', type = 'text' },
     { column = 'razed_name', type = 'text' },
     { column = 'preserved_railway', type = 'text' },
@@ -215,6 +209,29 @@ function train_protection(tags)
   return nil, 0
 end
 
+local electrification_values = osm2pgsql.make_check_values_func({'contact_line', 'yes', 'rail', 'ground-level_power_supply', '4th_rail', 'contact_line;rail', 'rail;contact_line'})
+function electrification_state(tags, ignore_future_states)
+  local electrified = tags['electrified']
+
+  if electrification_values(electrified) then
+    return 'present', tonumber(tags['voltage']), tonumber(tags['frequency'])
+  end
+  if (not ignore_future_states) and electrification_values(tags['construction:electrified']) then
+    return 'construction', tonumber(tags['construction:voltage']), tonumber(tags['construction:frequency'])
+  end
+  if (not ignore_future_states) and electrification_values(tags['proposed:electrified']) then
+    return 'proposed', tonumber(tags['proposed:voltage']), tonumber(tags['proposed:frequency'])
+  end
+  if electrified == 'no' and electrification_values(tags['deelectrified']) then
+    return 'deelectrified', nil, nil
+  end
+  if electrified == 'no' and electrification_values(tags['abandoned:electrified']) then
+    return 'abandoned', nil, nil
+  end
+
+  return nil, nil, nil
+end
+
 -- TODO clean up unneeded tags
 
 local railway_station_values = osm2pgsql.make_check_values_func({'station', 'halt', 'tram_stop', 'service_station', 'yard', 'junction', 'spur_junction', 'crossover', 'site'})
@@ -419,6 +436,8 @@ function osm2pgsql.process_way(object)
   if railway_values(tags.railway) then
     local railway_train_protection, railway_train_protection_rank = train_protection(tags)
 
+    local current_electrification_state, voltage, frequency = electrification_state(tags, true)
+    local _, future_voltage, future_frequency = electrification_state(tags, false)
     railway_line:insert({
       way = object:as_linestring(),
       railway = tags['railway'],
@@ -439,24 +458,18 @@ function osm2pgsql.process_way(object)
       maxspeed_forward = tags['maxspeed:forward'],
       maxspeed_backward = tags['maxspeed:backward'],
       preferred_direction = tags['railway:preferred_direction'],
-      electrified = tags['electrified'],
-      deelectrified = tags['deelectrified'],
-      frequency = tags['frequency'],
-      voltage = tags['voltage'],
+      electrification_state = current_electrification_state,
+      frequency = frequency,
+      voltage = voltage,
+      future_frequency = future_frequency,
+      future_voltage = future_voltage,
       gauge = tags['gauge'],
       construction_railway = tags['construction:railway'],
-      construction_electrified = tags['construction:electrified'],
-      construction_frequency = tags['construction:frequency'],
-      construction_voltage = tags['construction:voltage'],
       construction_gauge = tags['construction:gauge'],
       proposed_railway = tags['proposed:railway'],
-      proposed_electrified = tags['proposed:electrified'],
-      proposed_frequency = tags['proposed:frequency'],
-      proposed_voltage = tags['proposed:voltage'],
       disused_railway = tags['disused:railway'],
       abandoned_railway = tags['abandoned:railway'],
       abandoned_name = tags['abandoned:name'],
-      abandoned_electrified = tags['abandoned:electrified'],
       razed_railway = tags['razed:railway'],
       razed_name = tags['razed:name'],
       preserved_railway = tags['preserved:railway'],

import/sql/functions.sql

@@ -292,115 +292,31 @@ BEGIN
 END;
 $$ LANGUAGE plpgsql;
 
--- Get state of electrification
--- TODO move to import
-CREATE OR REPLACE FUNCTION railway_electrification_state(railway TEXT, electrified TEXT,
-  deelectrified TEXT, abandoned_electrified TEXT, construction_electrified TEXT,
-  proposed_electrified TEXT, ignore_future_states BOOLEAN) RETURNS TEXT AS $$
-DECLARE
-  state TEXT;
-  valid_values TEXT[] := ARRAY['contact_line', 'yes', 'rail', 'ground-level_power_supply', '4th_rail', 'contact_line;rail', 'rail;contact_line'];
-BEGIN
-  state := NULL;
-  IF electrified = ANY(valid_values) THEN
-    return 'present';
-  END IF;
-  IF electrified = 'no' THEN
-    state := 'no';
-  END IF;
-  IF NOT ignore_future_states AND construction_electrified = ANY(valid_values) THEN
-    RETURN 'construction';
-  END IF;
-  IF NOT ignore_future_states AND proposed_electrified = ANY(valid_values) THEN
-    RETURN 'proposed';
-  END IF;
-  IF state = 'no' AND deelectrified = ANY(valid_values) THEN
-    RETURN 'deelectrified';
-  END IF;
-  IF state = 'no' AND abandoned_electrified = ANY(valid_values) THEN
-    RETURN 'abandoned';
-  END IF;
-  RETURN state;
-END;
-$$ LANGUAGE plpgsql;
-
--- Get voltage for given state
-CREATE OR REPLACE FUNCTION railway_voltage_for_state(state TEXT, voltage TEXT, construction_voltage TEXT, proposed_voltage TEXT) RETURNS INTEGER AS $$
-BEGIN
-  IF state = 'present' THEN
-    RETURN railway_to_int(voltage);
-  END IF;
-  IF state = 'construction' THEN
-    RETURN railway_to_int(construction_voltage);
-  END IF;
-  IF state = 'proposed' THEN
-    RETURN railway_to_int(proposed_voltage);
-  END IF;
-  RETURN NULL;
-END;
-$$ LANGUAGE plpgsql;
-
--- Get frequency for given state
-CREATE OR REPLACE FUNCTION railway_frequency_for_state(state TEXT, frequency TEXT, construction_frequency TEXT, proposed_frequency TEXT) RETURNS FLOAT AS $$
-BEGIN
-  IF state = 'present' THEN
-    RETURN railway_to_float(frequency);
-  END IF;
-  IF state = 'construction' THEN
-    RETURN railway_to_float(construction_frequency);
-  END IF;
-  IF state = 'proposed' THEN
-    RETURN railway_to_float(proposed_frequency);
-  END IF;
-  RETURN NULL;
-END;
-$$ LANGUAGE plpgsql;
-
 -- Get label for electrification
-CREATE OR REPLACE FUNCTION railway_electrification_label(electrified TEXT, deelectrified TEXT,
-    construction_electrified TEXT, proposed_electrified TEXT, voltage TEXT, frequency TEXT,
-    construction_voltage TEXT, construction_frequency TEXT, proposed_voltage TEXT,
-    proposed_frequency TEXT) RETURNS TEXT AS $$
+CREATE OR REPLACE FUNCTION railway_electrification_label(voltage INT, frequency REAL) RETURNS TEXT AS $$
 DECLARE
-  volt TEXT;
-  freq TEXT;
   volt_int INTEGER;
-  kilovolt NUMERIC(3, 1);
   volt_text TEXT;
-  freq_text TEXT;
 BEGIN
-  -- Select right values for voltage and frequency part of the label
-  IF railway_no_to_null(electrified) IS NOT NULL OR railway_no_to_null(deelectrified) IS NOT NULL THEN
-    volt := voltage;
-    freq := frequency;
-  ELSIF railway_no_to_null(construction_electrified) IS NOT NULL THEN
-    volt := construction_voltage;
-    freq := construction_frequency;
-  ELSIF railway_no_to_null(proposed_electrified) IS NOT NULL THEN
-    volt := proposed_voltage;
-    freq := proposed_frequency;
-  ELSE
-    RETURN NULL;
-  END IF;
   -- Grounded sections
-  IF volt = '0' THEN
+  IF voltage = 0 THEN
     RETURN '0V';
   END IF;
   -- Round voltage nicely
-  volt_int := railway_to_int(volt);
+  volt_int := voltage::INT;
   IF volt_int < 1000 THEN
-    volt_text := volt || 'V';
+    volt_text := voltage || 'V';
   ELSIF volt_int % 1000 = 0 THEN
     volt_text := (volt_int/1000)::TEXT || 'kV';
   ELSE
     volt_text := round((volt_int::FLOAT / 1000::FLOAT)::numeric, 1) || 'kV';
   END IF;
   -- Output voltage and frequency
-  IF freq = '0' THEN
+  IF frequency = 0 THEN
     RETURN volt_text || ' =';
   END IF;
-  IF freq IS NOT NULL THEN
-    RETURN volt_text || ' ' || freq || 'Hz';
+  IF frequency IS NOT NULL THEN
+    RETURN volt_text || ' ' || frequency || 'Hz';
   END IF;
   RETURN volt_text;
 END;

import/sql/tile_views.sql

@@ -49,12 +49,12 @@ CREATE OR REPLACE VIEW railway_line_high AS
         railway_speed_label(speed_arr) AS speed_label,
         train_protection_rank,
         train_protection,
-        electrification_state_without_future AS electrification_state,
-        railway_voltage_for_state(electrification_state_without_future, voltage, construction_voltage, proposed_voltage) AS voltage,
-        railway_frequency_for_state(electrification_state_without_future, frequency, construction_frequency, proposed_frequency) AS frequency,
+        electrification_state,
+        voltage,
+        frequency,
         electrification_label,
-        railway_voltage_for_state(future_electrification_state, voltage, construction_voltage, proposed_voltage) AS future_voltage,
-        railway_frequency_for_state(future_electrification_state, frequency, construction_frequency, proposed_frequency) AS future_frequency,
+        future_voltage,
+        future_frequency,
         railway_to_int(gauge0) AS gaugeint0,
         gauge0,
         railway_to_int(gauge1) AS gaugeint1,
@@ -94,15 +94,12 @@ CREATE OR REPLACE VIEW railway_line_high AS
              railway_direction_speed_limit(preferred_direction,maxspeed, maxspeed_forward, maxspeed_backward) AS speed_arr,
              train_protection_rank,
              train_protection,
-             railway_electrification_state(railway, electrified, deelectrified, abandoned_electrified, NULL, NULL, true) AS electrification_state_without_future,
-             railway_electrification_label(electrified, deelectrified, construction_electrified, proposed_electrified, voltage, frequency, construction_voltage, construction_frequency, proposed_voltage, proposed_frequency) AS electrification_label,
-             railway_electrification_state(railway, electrified, deelectrified, abandoned_electrified, construction_electrified, proposed_electrified, false) AS future_electrification_state,
-             frequency,
+             electrification_state,
              voltage,
-             construction_frequency,
-             construction_voltage,
-             proposed_frequency,
-             proposed_voltage,
+             frequency,
+             railway_electrification_label(COALESCE(voltage, future_voltage), COALESCE(frequency, future_frequency)) AS electrification_label,
+             future_voltage,
+             future_frequency,
              railway_desired_value_from_list(1, COALESCE(gauge, construction_gauge)) AS gauge0,
              railway_desired_value_from_list(2, COALESCE(gauge, construction_gauge)) AS gauge1,
              railway_desired_value_from_list(3, COALESCE(gauge, construction_gauge)) AS gauge2,