Check user handle is available

src/main/api.zig

@@ -73,13 +73,9 @@ pub const ApiServer = struct {
     pub fn createUser(self: *ApiServer, info: CreateInfo(models.User)) !models.User {
         const id = Uuid.randV4(self.prng.random());
 
-        // check for handle dupes
+        if (try self.db.existsWhereEq(models.User, .handle, info.handle)) {
-        //while (iter.next()) |it| {
+            return error.HandleNotAvailable;
-        //if (std.mem.eql(u8, it.value_ptr.handle, info.handle)) {
+        }
-        //return error.DuplicateHandle;
-        //}
-        //}
-        // TODO: check for id dupes
 
         const user = reify(models.User, id, info);
         try self.db.insert(models.User, user);
@@ -88,10 +84,10 @@ pub const ApiServer = struct {
     }
 
     pub fn getNote(self: *ApiServer, id: Uuid, alloc: std.mem.Allocator) !?models.Note {
-        return self.db.getById(models.Note, id, alloc);
+        return self.db.getBy(models.Note, .id, id, alloc);
     }
 
     pub fn getUser(self: *ApiServer, id: Uuid, alloc: std.mem.Allocator) !?models.User {
-        return self.db.getById(models.User, id, alloc);
+        return self.db.getBy(models.User, .id, id, alloc);
     }
 };

src/main/controllers.zig

@@ -65,7 +65,10 @@ pub fn createUser(srv: *RequestServer, ctx: *http.server.Context, _: RouteArgs)
     const info = try utils.parseRequestBody(api.CreateInfo(models.User), ctx, srv.alloc);
     defer utils.freeRequestBody(info, srv.alloc);
 
-    const user = try srv.api.createUser(info);
+    const user = srv.api.createUser(info) catch |err| switch (err) {
+        error.HandleNotAvailable => return try utils.respondJson(ctx, .bad_request, .{ .@"error" = "handle not available" }, srv.alloc),
+        else => return err,
+    };
 
     try utils.respondJson(ctx, .created, user, srv.alloc);
 }

src/main/db.zig

@@ -30,13 +30,14 @@ const Query = struct {
     select: []const String,
     from: String,
     where: String = "id = ?",
-    limit: usize = 1,
+    limit: ?usize = null,
 
     pub fn str(comptime self: Query) String {
         comptime {
+            const limit_expr = if (self.limit == null) "" else std.fmt.comptimePrint(" LIMIT {}", .{self.limit});
             return std.fmt.comptimePrint(
-                "SELECT {s} FROM {s} WHERE {s} LIMIT {};",
+                "SELECT {s} FROM {s} WHERE {s}{s};",
-                .{ join(self.select, ", "), self.from, self.where, self.limit },
+                .{ join(self.select, ", "), self.from, self.where, limit_expr },
             );
         }
     }
@@ -123,36 +124,6 @@ pub const Database = struct {
         self.db.close();
     }
 
-    pub fn getByIdOld(self: *Database, comptime T: type, id: Uuid, alloc: std.mem.Allocator) !?T {
-        const fields = comptime fieldsExcept(T, &.{"id"});
-        const q = comptime (Query{
-            .select = fields,
-            .from = tableName(T),
-            .where = "id = ?",
-            .limit = 1,
-        }).str();
-
-        var stmt = try self.db.prepare(q);
-        defer stmt.finalize();
-
-        const id_str = id.toCharArray();
-        try stmt.bindText(1, &id_str);
-
-        const row = (try stmt.step()) orelse return null;
-        var val: T = undefined;
-        val.id = id;
-
-        inline for (fields) |f, i| {
-            @field(val, f) = switch (@TypeOf(@field(val, f))) {
-                // TODO: Handle allocation failures gracefully
-                []const u8 => row.getTextAlloc(i, alloc) catch unreachable,
-                else => @compileError("unknown type"),
-            };
-        }
-
-        return val;
-    }
-
     pub fn getById(self: *Database, comptime T: type, id: Uuid, alloc: std.mem.Allocator) !?T {
         return self.getBy(T, .id, id, alloc);
     }
@@ -193,6 +164,52 @@ pub const Database = struct {
         return result;
     }
 
+    pub fn countWhereEq(
+        self: *Database,
+        comptime T: type,
+        comptime field: std.meta.FieldEnum(T),
+        val: std.meta.fieldInfo(T, field).field_type,
+    ) !usize {
+        const field_name = std.meta.fieldInfo(T, field).name;
+        const q = comptime (Query{
+            .select = &.{"COUNT()"},
+            .from = tableName(T),
+            .where = field_name ++ " = ?",
+        }).str();
+
+        var stmt = try self.db.prepare(q);
+        defer stmt.finalize();
+
+        try stmt.bind(1, val);
+
+        const row = (try stmt.step()) orelse unreachable;
+        return @intCast(usize, try row.getI64(0));
+    }
+
+    // TODO: don't super like this query
+    pub fn existsWhereEq(
+        self: *Database,
+        comptime T: type,
+        comptime field: std.meta.FieldEnum(T),
+        val: std.meta.fieldInfo(T, field).field_type,
+    ) !bool {
+        const field_name = std.meta.fieldInfo(T, field).name;
+        const q = comptime (Query{
+            .select = &.{"COUNT(1)"},
+            .from = tableName(T),
+            .where = field_name ++ " = ?",
+            .limit = 1,
+        }).str();
+
+        var stmt = try self.db.prepare(q);
+        defer stmt.finalize();
+
+        try stmt.bind(1, val);
+
+        const row = (try stmt.step()) orelse unreachable;
+        return (try row.getI64(0)) > 0;
+    }
+
     pub fn getNoteById(self: *Database, id: Uuid, alloc: std.mem.Allocator) !?models.Note {
         return self.getById(models.Note, id, alloc);
     }