all: generate json, not code

This includes modifying horsebot to use the generated JSON, as well as
moving the generator to another cmd/ directory.

Remove the generated code while we're here.
Koka tests still have to be updated, but it requires a JSON parser.

cmd/horsegen/sql/affinity.sql

@@ -0,0 +1,60 @@
+WITH pairs AS (
+	SELECT
+		a.id AS id_a,
+		b.id AS id_b
+	FROM chara_data a
+		JOIN chara_data b ON a.id < b.id
+	-- Exclude characters who have no succession relations defined.
+	WHERE a.id IN (SELECT chara_id FROM succession_relation_member)
+		AND b.id IN (SELECT chara_id FROM succession_relation_member)
+), trios AS (
+	SELECT
+		a.id AS id_a,
+		b.id AS id_b,
+		c.id AS id_c
+	FROM chara_data a
+		JOIN chara_data b ON a.id < b.id
+		JOIN chara_data c ON a.id < c.id AND b.id < c.id
+	-- Exclude characters who have no succession relations defined.
+	WHERE a.id IN (SELECT chara_id FROM succession_relation_member)
+		AND b.id IN (SELECT chara_id FROM succession_relation_member)
+		AND c.id IN (SELECT chara_id FROM succession_relation_member)
+), pair_relations AS (
+	SELECT
+		ra.relation_type,
+		ra.chara_id AS id_a,
+		rb.chara_id AS id_b
+	FROM succession_relation_member ra
+		JOIN succession_relation_member rb ON ra.relation_type = rb.relation_type
+), trio_relations AS (
+	SELECT
+		ra.relation_type,
+		ra.chara_id AS id_a,
+		rb.chara_id AS id_b,
+		rc.chara_id AS id_c
+	FROM succession_relation_member ra
+		JOIN succession_relation_member rb ON ra.relation_type = rb.relation_type
+		JOIN succession_relation_member rc ON ra.relation_type = rc.relation_type
+), affinity AS (
+	SELECT
+		pairs.*,
+		0 AS id_c,
+		SUM(IFNULL(relation_point, 0)) AS base_affinity
+	FROM pairs
+		LEFT JOIN pair_relations rp ON pairs.id_a = rp.id_a AND pairs.id_b = rp.id_b
+		LEFT JOIN succession_relation sr ON rp.relation_type = sr.relation_type
+	GROUP BY pairs.id_a, pairs.id_b
+
+	UNION ALL
+
+	SELECT
+		trios.*,
+		SUM(IFNULL(relation_point, 0)) AS base_affinity
+	FROM trios
+		LEFT JOIN trio_relations rt ON trios.id_a = rt.id_a AND trios.id_b = rt.id_b AND trios.id_c = rt.id_c
+		LEFT JOIN succession_relation sr ON rt.relation_type = sr.relation_type
+	GROUP BY trios.id_a, trios.id_b, trios.id_c
+)
+SELECT * FROM affinity
+WHERE base_affinity != 0
+ORDER BY id_a, id_b, id_c