Store a target's settings as columns (closes #543)

A target's settings move from the per-type JSON string in
targets.config to columns: url, headers, timeout_seconds,
forward_query, archive_expiry and archive_rotation. A column a type
does not use stays empty. headers holds the header map as JSON text
through GORM's JSON serializer, and archive_expiry holds a
time.Duration, 0 meaning never, so nothing that reads a target parses
it. The forms check each setting once, with the same refusals and
messages, and the edit form is filled from the columns, so the
per-type config structs, their parsers and the "could not be read"
branches are gone. A delivery task carries the six settings in place
of the JSON string.

Model: opus-5-5

internal/archive/writer.go

@@ -1,7 +1,6 @@
 package archive
 
 import (
-	"encoding/json"
 	"errors"
 	"fmt"
 	"io/fs"
@@ -18,8 +17,9 @@ import (
 	"sneak.berlin/go/webhooker/internal/gormlog"
 )
 
-// ExpiryNever is the expiry sentinel (and default) that
-// disables pruning so archived rows are kept forever.
+// ExpiryNever is the archive expiry, as the target forms take it,
+// that disables pruning so archived rows are kept forever. It is
+// stored as an ArchiveExpiry of 0.
 const ExpiryNever = "never"
 
 // archiveReopenDebounce bounds how often an archive file is
@@ -79,19 +79,6 @@ var (
 	)
 )
 
-// DatabaseTargetConfig is the optional per-target JSON config
-// for a database (archive) target.
-type DatabaseTargetConfig struct {
-	// Expiry is a Go duration (e.g. "720h") after which
-	// archived rows are pruned, or "never" (the default) to
-	// keep them forever.
-	Expiry string `json:"expiry"`
-
-	// Rotation is none (the default), monthly, daily or hourly: see
-	// archivePeriod.
-	Rotation string `json:"rotation"`
-}
-
 // archivedEvent is one fully captured webhook event stored in a
 // database target's archive for long-term retention. It is a
 // self-contained copy — independent of the per-webhook event
@@ -112,63 +99,20 @@ type archivedEvent struct {
 	ArchivedAt time.Time `gorm:"index"`
 }
 
-// ParseExpiry reads the optional expiry from a database
-// target's config JSON. An empty config, an empty expiry, or
-// the literal "never" all mean keep forever, returned as a zero
-// duration. Any other value must parse as a positive Go
-// duration; a set-but-invalid value (unparseable, zero, or
-// negative) is an error rather than a silent default, matching
-// ValidateExpiry at target creation.
-func ParseExpiry(
-	configJSON string,
-) (time.Duration, error) {
-	if configJSON == "" {
-		return 0, nil
-	}
-
-	var cfg DatabaseTargetConfig
-
-	err := json.Unmarshal([]byte(configJSON), &cfg)
-	if err != nil {
-		return 0, fmt.Errorf(
-			"parsing database target config: %w", err,
-		)
-	}
-
-	if cfg.Expiry == "" || cfg.Expiry == ExpiryNever {
-		return 0, nil
-	}
-
-	dur, err := time.ParseDuration(cfg.Expiry)
-	if err != nil {
-		return 0, fmt.Errorf(
-			"parsing archive expiry %q: %w", cfg.Expiry, err,
-		)
-	}
-
-	if dur <= 0 {
-		return 0, fmt.Errorf(
-			"%w: %q", errArchiveExpiryNotPositive, cfg.Expiry,
-		)
-	}
-
-	return dur, nil
-}
-
-// ValidateExpiry checks a user-supplied archive expiry
-// for a database target at configuration time. Valid values are
-// empty, "never" (both meaning keep forever), or a positive Go
-// duration such as "720h". Anything else is an error, so a bad
-// expiry is rejected when the target is created rather than
-// failing every subsequent delivery.
-func ValidateExpiry(expiry string) error {
+// ParseExpiry reads a user-supplied archive expiry for a database
+// target, as the target forms submit it, into the ArchiveExpiry the
+// target stores. Empty and "never" both mean keep forever, which is
+// 0; anything else must be a positive Go duration such as "720h". Any
+// other value is an error, so a bad expiry is refused at the form
+// rather than stored.
+func ParseExpiry(expiry string) (time.Duration, error) {
 	if expiry == "" || expiry == ExpiryNever {
-		return nil
+		return 0, nil
 	}
 
 	dur, err := time.ParseDuration(expiry)
 	if err != nil {
-		return fmt.Errorf(
+		return 0, fmt.Errorf(
 			"expiry must be %q or a Go duration "+
 				"such as \"720h\": %w",
 			ExpiryNever, err,
@@ -176,12 +120,12 @@ func ValidateExpiry(expiry string) error {
 	}
 
 	if dur <= 0 {
-		return fmt.Errorf(
+		return 0, fmt.Errorf(
 			"%w: %q", errArchiveExpiryNotPositive, expiry,
 		)
 	}
 
-	return nil
+	return dur, nil
 }
 
 // archiveWriter owns one database target's archive SQLite files.