+COMMENT ON COLUMN word.alt IS 'alternate forms with equivalent meaning';
+COMMENT ON COLUMN word.lang IS 'ISO 639 language code matching wikipedia subdomain';
+COMMENT ON COLUMN word.cat IS 'primary hierarchical classification';
+COMMENT ON COLUMN word.ref IS 'reference to equivalent en translation';
+COMMENT ON COLUMN word.prio IS 'difficulty level or importance; lower values have precedence';
+COMMENT ON COLUMN word.grade IS 'ascending hierarchical order, preceding default alphabetical';
+COMMENT ON COLUMN word.cover IS 'highlight if selected';
+COMMENT ON COLUMN word.image IS 'metadata of illustrations, including downloaded URI and ImageMagick convert options';
+COMMENT ON COLUMN word.wptitle IS 'reference Wikipedia article';
+COMMENT ON COLUMN word.story IS 'paragraph defining or describing the entity, wikipedia intro';
+COMMENT ON COLUMN word.updated IS 'last significant change';
+COMMENT ON COLUMN word.creator IS 'user responsible for initial submit';
+
+CREATE TABLE kind (
+ word integer NOT NULL REFERENCES word (id),
+ cat integer NOT NULL REFERENCES word (id),
+ UNIQUE (word, cat),
+ truth smallint NOT NULL DEFAULT '50',
+ creator integer REFERENCES login (id),
+ created timestamptz DEFAULT now(),
+ updated timestamptz,
+ id integer NOT NULL PRIMARY KEY GENERATED BY DEFAULT AS IDENTITY
+);
+
+COMMENT ON COLUMN kind.truth IS 'link validity ranging from 0 (never) to 100 (always)';
+
+CREATE OR REPLACE FUNCTION exportform(word) RETURNS text AS $$
+ SELECT concat(
+ coalesce($1.ref, $1.id), ':',
+ $1.prio, CASE WHEN $1.cover THEN 'c' ELSE '' END, ':',
+ array_to_string($1.form || $1.alt, '/')
+ );
+$$ LANGUAGE SQL IMMUTABLE;
+
+CREATE OR REPLACE VIEW _word_ref AS
+ SELECT
+ r.form, r.alt, r.lang,
+ coalesce(r.cat, w.cat ) cat, --TODO translate w?
+ coalesce(r.ref, r.id ) "ref",
+ coalesce(r.prio, w.prio ) prio,
+ coalesce(r.grade, w.grade ) grade,
+ coalesce(r.cover, w.cover ) cover,
+ coalesce(r.image, w.image ) image,
+ coalesce(r.wptitle, w.wptitle) wptitle,
+ coalesce(r.story, w.story ) story,
+ r.creator, r.created, r.updated,
+ CASE WHEN nullif(r.image, '{}') IS NOT NULL THEN r.id
+ WHEN nullif(w.image, '{}') IS NOT NULL THEN w.id END id -- image id
+ FROM word r
+ LEFT JOIN word w ON w.id = r.ref;
+
+CREATE OR REPLACE VIEW _word_tree AS
+ WITH RECURSIVE r AS (
+ SELECT w.ref, w.lang, w.cat, w.grade, w.form, NULL::int trans
+ FROM _word_ref w
+ UNION ALL
+ SELECT r.ref, r.lang, w.cat,
+ CASE WHEN w.lang=r.lang OR t.lang=r.lang THEN r.grade ELSE w.grade END,
+ CASE WHEN w.lang=r.lang OR t.lang=r.lang THEN r.form ELSE w.form END,
+ CASE WHEN w.lang=r.lang OR t.lang=r.lang THEN w.id END
+ FROM r JOIN word w ON w.id = r.cat
+ LEFT JOIN word t ON w.id = t.ref AND t.lang = r.lang
+ WHERE r.trans IS NULL
+ )
+ SELECT ref, lang, trans cat, grade, form FROM r WHERE trans IS NOT NULL
+ ORDER BY cat, grade, form, ref;
+
+CREATE OR REPLACE VIEW _word AS
+ SELECT
+ (SELECT array_agg(coalesce(ref, id)) FROM _word_tree
+ WHERE cat = w.ref AND lang = w.lang) sub,
+ w.*
+ FROM _word_ref w
+ ;
+
+CREATE OR REPLACE VIEW _cat_words AS
+ SELECT exportform(word.*) form, sub.*, word.lang, word.ref
+ FROM word RIGHT JOIN (
+ SELECT cat id, array_agg(exportform(word.*) ORDER BY grade, form) forms
+ FROM word WHERE ref IS NULL GROUP BY cat
+ ) sub USING (id);