add list claims and improve error handling

store.go

@@ -5,6 +5,7 @@ import (
 	"database/sql"
 	_ "embed"
 	"fmt"
+	"strings"
 
 	_ "github.com/mattn/go-sqlite3"
 )
@@ -12,34 +13,55 @@ import (
 //go:embed migrations/init.sql
 var initScript string
 
-const (
-	CLAIM_TYPE_AREA = iota
-	CLAIM_TYPE_REGION
-	CLAIM_TYPE_TRADE
-)
+type ClaimType string
 
-var claimTypeEnum = map[string]int{
-	"area":   CLAIM_TYPE_AREA,
-	"region": CLAIM_TYPE_REGION,
-	"trade":  CLAIM_TYPE_TRADE,
+func ClaimTypeFromString(s string) (ClaimType, error) {
+	switch s {
+	case CLAIM_TYPE_AREA:
+		return CLAIM_TYPE_AREA, nil
+	case CLAIM_TYPE_REGION:
+		return CLAIM_TYPE_REGION, nil
+	case CLAIM_TYPE_TRADE:
+		return CLAIM_TYPE_TRADE, nil
+	}
+	return "", fmt.Errorf("no claim type matching '%s'", s)
 }
 
-var claimTypeEnumVals = map[int]string{
+const (
+	CLAIM_TYPE_AREA   = "area"
+	CLAIM_TYPE_REGION = "region"
+	CLAIM_TYPE_TRADE  = "trade"
+)
+
+var claimTypeToColumn = map[ClaimType]string{
 	CLAIM_TYPE_AREA:   "area",
 	CLAIM_TYPE_REGION: "region",
-	CLAIM_TYPE_TRADE:  "trade",
-}
-
-var claimTypeToColumn = map[string]string{
-	"area":   "area",
-	"region": "region",
-	"trade":  "trade_node",
+	CLAIM_TYPE_TRADE:  "trade_node",
 }
 
 type Store struct {
 	db *sql.DB
 }
 
+type Claim struct {
+	ID     int
+	Player string
+	Name   string
+	Type   ClaimType
+}
+
+func (c Claim) String() string {
+	return fmt.Sprintf("id=%d player=%s claim_type=%s name=%s", c.ID, c.Player, c.Type, c.Name)
+}
+
+type ErrConflict struct {
+	Conflicts []string
+}
+
+func (ec ErrConflict) Error() string {
+	return fmt.Sprintf("found conflicting provinces: %s", strings.Join(ec.Conflicts, ", "))
+}
+
 func NewStore(conn string) (*Store, error) {
 	db, err := sql.Open("sqlite3", conn)
 	if err != nil {
@@ -56,7 +78,7 @@ func NewStore(conn string) (*Store, error) {
 	}, nil
 }
 
-func (s *Store) Claim(ctx context.Context, player, province string, typ int) error {
+func (s *Store) Claim(ctx context.Context, player, province string, claimType ClaimType) error {
 	tx, err := s.db.Begin()
 	if err != nil {
 		return fmt.Errorf("failed to begin transaction: %w", err)
@@ -64,24 +86,32 @@ func (s *Store) Claim(ctx context.Context, player, province string, typ int) err
 	defer tx.Commit()
 
 	// Check conflicts
-	stmt, err := s.db.PrepareContext(ctx, fmt.Sprintf(`SELECT COUNT(1) FROM provinces WHERE provinces.%s = ? and provinces.name in (
+	stmt, err := s.db.PrepareContext(ctx, fmt.Sprintf(`SELECT provinces.name FROM provinces WHERE provinces.%s = ? and provinces.name in (
 	SELECT provinces.name FROM claims LEFT JOIN provinces ON claims.val = provinces.trade_node WHERE claims.claim_type = 'trade'
 	UNION SELECT provinces.name from claims LEFT JOIN provinces ON claims.val = provinces.region WHERE claims.claim_type = 'region'
 	UNION SELECT provinces.name from claims LEFT JOIN provinces ON claims.val = provinces.area WHERE claims.claim_type = 'area'
-)`, claimTypeToColumn[claimTypeEnumVals[typ]]))
+)`, claimTypeToColumn[claimType]))
 	if err != nil {
 		return fmt.Errorf("failed to prepare conflicts query: %w", err)
 	}
 
-	row := stmt.QueryRowContext(ctx, province)
-	var count int
-	err = row.Scan(&count)
+	rows, err := stmt.QueryContext(ctx, province)
 	if err != nil {
-		return fmt.Errorf("failed to get count of conflicting provinces: %w", err)
+		return fmt.Errorf("failed to get conflicting provinces: %w", err)
 	}
 
-	if count > 0 {
-		return fmt.Errorf("found %d conflicting provinces", count)
+	conflicts := make([]string, 0)
+	for rows.Next() {
+		var p string
+		err = rows.Scan(&p)
+		if err != nil {
+			return fmt.Errorf("failed to scan row: %w", err)
+		}
+		conflicts = append(conflicts, p)
+	}
+
+	if len(conflicts) > 0 {
+		return ErrConflict{Conflicts: conflicts}
 	}
 
 	stmt, err = s.db.PrepareContext(ctx, "INSERT INTO claims (player, claim_type, val) VALUES (?, ?, ?)")
@@ -89,10 +119,41 @@ func (s *Store) Claim(ctx context.Context, player, province string, typ int) err
 		return fmt.Errorf("failed to prepare claim query: %w", err)
 	}
 
-	_, err = stmt.ExecContext(ctx, player, claimTypeEnumVals[typ], province)
+	_, err = stmt.ExecContext(ctx, player, claimType, province)
 	if err != nil {
 		return fmt.Errorf("failed to insert claim: %w", err)
 	}
 
 	return nil
 }
+
+func (s *Store) ListClaims(ctx context.Context) ([]Claim, error) {
+	stmt, err := s.db.PrepareContext(ctx, `SELECT id, player, claim_type, val FROM claims`)
+	if err != nil {
+		return nil, fmt.Errorf("failed to prepare query: %w", err)
+	}
+
+	rows, err := stmt.QueryContext(ctx)
+	if err != nil {
+		return nil, fmt.Errorf("failed to execute query: %w", err)
+	}
+
+	claims := make([]Claim, 0)
+	for rows.Next() {
+		c := Claim{}
+		var rawType string
+		err = rows.Scan(&c.ID, &c.Player, &rawType, &c.Name)
+		if err != nil {
+			return nil, fmt.Errorf("failed to scan row: %w", err)
+		}
+		cl, err := ClaimTypeFromString(rawType)
+		if err != nil {
+			return nil, fmt.Errorf("unexpected error converting raw claim type: %w", err)
+		}
+		c.Type = cl
+
+		claims = append(claims, c)
+	}
+
+	return claims, nil
+}