tapdb: add script_keys.key_type column

With this commit we add a new numeric type for the type of a script key.
This will be a Golang enum/const that's going to be assigned manually
when declaring a key as known.
For existing keys, we'll add a new mechanism in the following commits
that runs on startup after we detect a SQL migration was applied that
will attempt the detection of the type of those keys.

Author: guggero

tapdb/migrations.go

@@ -22,7 +22,7 @@ const (
 	// daemon.
 	//
 	// NOTE: This MUST be updated when a new migration is added.
-	LatestMigrationVersion = 30
+	LatestMigrationVersion = 31
 )
 
 // MigrationTarget is a functional option that can be passed to applyMigrations

tapdb/sqlc/addrs.sql.go

@@ -0,0 +1 @@
+ALTER TABLE script_keys DROP COLUMN key_type;

tapdb/sqlc/assets.sql.go

@@ -0,0 +1,7 @@
+-- The key_type column is used to store the type of key that is stored in the
+-- script_keys table. The type is a Golang numeric type that will have values
+-- such as BIP-0086, script path with custom (externally defined) script, script
+-- path with Taproot Asset Channel related script, etc. The NULL value
+-- will mean the type is not known. Existing script keys at the time of this
+-- migration will be updated at startup after the migration is applied.
+ALTER TABLE script_keys ADD COLUMN key_type SMALLINT;

tapdb/sqlc/migrations/000031_script_key_type.down.sql

@@ -141,6 +141,7 @@ SELECT seedling_id, asset_name, asset_type, asset_version, asset_supply,
     script_keys.tweak AS script_key_tweak,
     script_keys.tweaked_script_key,
     script_keys.declared_known AS script_key_declared_known,
+    script_keys.key_type AS script_key_type,
     internal_keys.raw_key AS script_key_raw,
     internal_keys.key_family AS script_key_fam,
     internal_keys.key_index AS script_key_index,
@@ -855,27 +856,37 @@ WHERE txid = $1;
 
 -- name: UpsertScriptKey :one
 INSERT INTO script_keys (
-    internal_key_id, tweaked_script_key, tweak, declared_known
+    internal_key_id, tweaked_script_key, tweak, declared_known, key_type
 ) VALUES (
-    $1, $2, $3, $4
+    $1, $2, $3, $4, $5
 )  ON CONFLICT (tweaked_script_key)
-    -- Overwrite the declared_known and tweak fields if they were previously
-    -- unknown.
+    -- Overwrite the declared_known, key_type and tweak fields if they were
+    -- previously unknown.
     DO UPDATE SET 
       tweaked_script_key = EXCLUDED.tweaked_script_key,
       -- If the script key was previously unknown, we'll update to the new
-      -- value.
-      declared_known = CASE
-                         WHEN script_keys.declared_known IS NULL OR script_keys.declared_known = FALSE
-                         THEN COALESCE(EXCLUDED.declared_known, script_keys.declared_known)
-                         ELSE script_keys.declared_known
-                       END,
+      -- value, if that is non-NULL.
+      declared_known =
+          CASE
+             WHEN COALESCE(script_keys.declared_known, FALSE) = FALSE
+             THEN COALESCE(EXCLUDED.declared_known, script_keys.declared_known)
+             ELSE script_keys.declared_known
+           END,
       -- If the tweak was previously unknown, we'll update to the new value.
-      tweak = CASE
-                     WHEN script_keys.tweak IS NULL
-                     THEN COALESCE(EXCLUDED.tweak, script_keys.tweak)
-                     ELSE script_keys.tweak
-                 END
+      tweak =
+          CASE
+             WHEN script_keys.tweak IS NULL
+             THEN COALESCE(EXCLUDED.tweak, script_keys.tweak)
+             ELSE script_keys.tweak
+           END,
+      -- We only overwrite the key type with a value that does not mean
+      -- "unknown" (0 or NULL).
+        key_type =
+          CASE
+             WHEN COALESCE(EXCLUDED.key_type, 0) != 0
+             THEN EXCLUDED.key_type
+             ELSE script_keys.key_type
+           END
 RETURNING script_key_id;
 
 -- name: FetchScriptKeyIDByTweakedKey :one
@@ -890,6 +901,13 @@ JOIN internal_keys
   ON script_keys.internal_key_id = internal_keys.key_id
 WHERE script_keys.tweaked_script_key = $1;
 
+-- name: FetchUnknownTypeScriptKeys :many
+SELECT sqlc.embed(script_keys), sqlc.embed(internal_keys)
+FROM script_keys
+JOIN internal_keys
+  ON script_keys.internal_key_id = internal_keys.key_id
+WHERE script_keys.key_type IS NULL;
+
 -- name: FetchInternalKeyLocator :one
 SELECT key_family, key_index
 FROM internal_keys

tapdb/sqlc/migrations/000031_script_key_type.up.sql

@@ -653,7 +653,7 @@ CREATE TABLE script_keys (
     -- An optional tweak for the script_key. If NULL, the raw_key may be
     -- tweaked BIP-0086 style.
     tweak BLOB
-, declared_known BOOLEAN);
+, declared_known BOOLEAN, key_type SMALLINT);
 
 CREATE TABLE tapscript_edges (
         edge_id INTEGER PRIMARY KEY,