\i wm.sql

-- https://stackoverflow.com/questions/19982373/which-tools-libraries-do-you-use-to-unit-test-your-pl-pgsql
create or replace function assert_equals(expected anyelement, actual anyelement) returns void as $$
begin
  if expected = actual or (expected is null and actual is null) then
    --do nothing
  else
    raise exception 'Assertion Error. Expected <%> but was <%>', expected, actual;
  end if;
end $$ language plpgsql;

drop function if exists dbg_geomsummary;
create function dbg_geomsummary(geoms geometry[]) returns void as $$
  declare i int4;
begin
  raise notice 'len: %', array_length(geoms, 1);
  for i in 1..array_length(geoms, 1) loop
    raise notice '% %: %', st_geometrytype(geoms[i]), lpad(i::text, 2, '0'), st_astext(geoms[i]);
  end loop;
end
$$ language plpgsql;

drop table if exists wm_figures;
create table wm_figures (name text, way geometry);
-- add fig8.gpkg to postgis:
--   ogr2ogr -update -f PostgreSQL PG:"host=127.0.0.1 user=osm password=osm dbname=osm" fig8.gpkg
-- to "normalize" a new line when it's in `f`:
--   select st_astext(st_snaptogrid(st_transscale(geometry, -19.5, .016, 4000, 4000), 1)) from f;
insert into wm_figures (name, way) values
  ('fig3',          'LINESTRING(0 0,12 0,13 4,20 2,20 0,32 0,33 10,38 16,43 15,44 10,44 0,60 0)'::geometry),
  ('fig3-1',        'LINESTRING(0 0,12 0,13 4,20 2,20 0,32 0,33 10,38 16,43 15,44 10,44 0)'::geometry),
  ('fig5',          'LINESTRING(0 39,19 52,27 77,26 104,41 115,49 115,65 103,65 75,53 45,63 15,91 0)'::geometry),
  ('fig6',          'LINESTRING(84 47,91 59,114 64,122 80,116 92,110 93,106 106,117 118,136 107,135 76,120 45,125 39,141 39,147 32)'::geometry),
  ('fig8',          'LINESTRING(173 12,174 10,180 8,186 8,186 13,191 11,189 6,201 5,203 11,216 16,216 6,222 6,229 3,236 2,239 6,243 8,248 6)'::geometry),
  ('inflection-1',  'LINESTRING(110 24,114 20,133 20,145 15,145 0,136 8,123 10,114 10,111 2)'::geometry),
  ('multi-island',  'MULTILINESTRING((-15 10,-10 10,-5 11,0 11,5 11,10 10,11 9,13 10,15 9),(-5 11,-2 15,0 16,2 15,5 11))'::geometry),
  ('selfcrossing-1','LINESTRING(-27 180,-20 166,-21 142,-18 136,55 136,55 136,71 145,44 165,37 146,22 145,14 164,11 164,3 146,-12 146,-13 176,-18 184)'::geometry),
  ('isolated-1',    'LINESTRING(-50 103,-48 102,-30 103,-31 105,-31 107,-27 107,-26 103,-6 103,-4 104)'::geometry),
  ('isolated-2',    'LINESTRING(250 100,246 104,234 105,230 106,225 101,224 93,217 78,206 69)'::geometry);

insert into wm_figures (name, way) values ('fig6-rev',ST_Reverse(
    ST_Translate((select way from wm_figures where name='fig6'), 60, 0)));
insert into wm_figures (name, way) values ('fig6-combi', ST_Union(
      ST_Translate((select way from wm_figures where name='fig6'), 0, 90),
      ST_Translate((select way from wm_figures where name='fig6'), 80, 90)
  ));

insert into wm_figures (name, way) values ('selfcrossing-1-rev',ST_Reverse(
    ST_Translate((select way from wm_figures where name='selfcrossing-1'), 0, 60)));

update wm_figures set way=st_setsrid(way, 3857);

delete from wm_debug where name in (select distinct name from wm_figures);
delete from wm_demo where name in (select distinct name from wm_figures);
insert into wm_demo (name, way) select name, ST_SimplifyWM(way, .1, null, name) from wm_figures where name not in ('fig8', 'isolated-1');
insert into wm_demo (name, way) select name, ST_SimplifyWM(way, 14, null, name) from wm_figures where name in ('fig8', 'isolated-1', 'isolated-2');

drop function if exists wm_debug_get;
create function wm_debug_get( _stage text, _name text, OUT ways geometry[]) as $$
declare
begin
  ways = array((select way from wm_debug where stage=_stage and name=_name order by id));
end $$ language plpgsql;

do $$
declare
  vbends geometry[];
begin
  vbends = wm_debug_get('bbends', 'fig3');
  perform assert_equals(5, array_length(vbends, 1));
  perform assert_equals('LINESTRING(0 0,12 0,13 4)', st_astext(vbends[1]));
  perform assert_equals('LINESTRING(12 0,13 4,20 2,20 0)', st_astext(vbends[2]));
  perform assert_equals('LINESTRING(20 2,20 0,32 0,33 10)', st_astext(vbends[3]));
  perform assert_equals('LINESTRING(32 0,33 10,38 16,43 15,44 10,44 0)', st_astext(vbends[4]));
  perform assert_equals(4, array_length(wm_detect_bends((select way from wm_figures where name='fig3-1')), 1));
  select wm_detect_bends((select way from wm_figures where name='fig5')) into vbends;
  perform assert_equals(3, array_length(vbends, 1));
end $$ language plpgsql;

do $$
declare
  vbends geometry[];
  vinflections geometry[];
begin
  vinflections = wm_debug_get('cinflections', 'fig5');
  perform assert_equals('LINESTRING(0 39,19 52,27 77)', st_astext(vinflections[1]));
  perform assert_equals('LINESTRING(19 52,27 77,26 104,41 115,49 115,65 103,65 75,53 45)', st_astext(vinflections[2]));
  perform assert_equals('LINESTRING(65 75,53 45,63 15,91 0)', st_astext(vinflections[3]));

  -- inflections-1, the example in fix_gentle_inflections docstring
  select array((select way from wm_debug where name='inflection-1' and stage='bbends')) into vbends;
  select array((select way from wm_debug where name='inflection-1' and stage='cinflections')) into vinflections;
  perform assert_equals(vbends[1], vinflections[1]); -- unchanged
  perform assert_equals('LINESTRING(114 20,133 20,145 15,145 0,136 8,123 10,114 10)', st_astext(vinflections[2]));
  perform assert_equals('LINESTRING(123 10,114 10,111 2)', st_astext(vinflections[3]));
end $$ language plpgsql;

do $$
declare
  fig6 constant text default 'LINESTRING(84 47,91 59,114 64,120 45,125 39,141 39,147 32)';
  selfcrossing1 constant text default 'LINESTRING(-27 180,-20 166,-13 176,-18 184)';
  vcrossings geometry[];
  mutated boolean;
begin
  select * from wm_self_crossing(wm_debug_get('cinflections', 'fig6')) into vcrossings, mutated;
  perform assert_equals(true, mutated);
  perform assert_equals(
    fig6,
    (select st_astext(
        st_linemerge(st_union(way))
    ) from (select unnest(vcrossings) way) a)
  );

  select * from wm_self_crossing(wm_debug_get('cinflections', 'fig6-rev')) into vcrossings, mutated;
  perform assert_equals(true, mutated);
  perform assert_equals(
    fig6,
    (select st_astext(
        st_translate(st_reverse(st_linemerge(st_union(way))), -60, 0)
    ) from (select unnest(vcrossings) way) a)
  );

  select * from wm_self_crossing(wm_debug_get('cinflections', 'fig6-combi')) into vcrossings, mutated;
  perform assert_equals(true, mutated);
  perform assert_equals(
    'MULTILINESTRING((84 137,91 149,114 154,120 135,125 129,141 129,147 122),(164 137,171 149,194 154,200 135,205 129,221 129,227 122))',
    (select st_astext(
        st_linemerge(st_union(way))
    ) from (select unnest(vcrossings) way) a)
  );


  select * from wm_self_crossing(wm_debug_get('cinflections', 'selfcrossing-1')) into vcrossings, mutated;
  perform assert_equals(true, mutated);
  perform assert_equals(
    selfcrossing1,
    (select st_astext(
        st_linemerge(st_union(way))
    ) from (select unnest(vcrossings) way) a)
  );

  select * from wm_self_crossing(wm_debug_get('cinflections', 'selfcrossing-1-rev')) into vcrossings, mutated;
  perform assert_equals(true, mutated);
  perform assert_equals(
    selfcrossing1,
    (select st_astext(
        st_translate(st_reverse(st_linemerge(st_union(way))), 0, -60)
    ) from (select unnest(vcrossings) way) a)
  );

end $$ language plpgsql;

-- verifying bends in fig8 are eliminated like explained in the WM paper
do $$
declare
  fig8gen2 constant text default 'LINESTRING(173 12,174 10,180 8,186 8,189 6,201 5,203 11,216 16,216 6,229 3,236 2,239 6,243 8,248 6)';
  fig8gen3 constant text default 'LINESTRING(173 12,174 10,180 8,189 6,201 5,203 11,216 16,216 6,229 3,236 2,239 6,243 8,248 6)';
  eliminations geometry[];
begin
  eliminations = wm_debug_get('afigures', 'fig8');
  perform assert_equals(fig8gen2, st_astext(eliminations[2]));
  perform assert_equals(fig8gen3, st_astext(eliminations[3]));
end $$ language plpgsql;

-- testing wm_exaggerate_bend in isolation
do $$
declare
  fig3b2 geometry;
  bend geometry;
  size float;
begin
  select way from wm_debug where name='fig3' and stage='bbends' and gen=1 and nbend=2 into fig3b2;
  size = wm_adjsize(fig3b2);
  bend = wm_exaggerate_bend(fig3b2, size, 50.);
  perform assert_equals('ST_LineString', st_geometrytype(bend));
  insert into wm_debug(stage, name, gen, nbend, way) values('manual', 'fig3', 1, 1, bend);
end $$ language plpgsql;