using Invercargill;
using Invercargill.DataStructures;
using Json;

namespace Spry.Users {

    public class User : GLib.Object {
        // Identity
        public string id { get; set; }
        public string username { get; set; }
        public string email { get; set; }
        public string password_hash { get; set; }

        // Metadata
        public DateTime created_at { get; set; }
        public DateTime? updated_at { get; set; }

        // Permissions - stored as JSON array of strings
        public Vector<string> permissions { get; set; default = new Vector<string>(); }

        // Application-specific data - stored as JSON object
        public Dictionary<string, string> app_data { get; set; default = new Dictionary<string, string>(); }

        public User() {
            id = "";
            username = "";
            email = "";
            password_hash = "";
            created_at = new DateTime.now_utc();
        }

        public static User from_json(Json.Object obj) {
            var user = new User();

            // Required string fields - use has_member and null coalescing for safety
            user.id = obj.has_member("id") ? (obj.get_string_member("id") ?? "") : "";
            user.username = obj.has_member("username") ? (obj.get_string_member("username") ?? "") : "";
            user.email = obj.has_member("email") ? (obj.get_string_member("email") ?? "") : "";
            user.password_hash = obj.has_member("password_hash") ? (obj.get_string_member("password_hash") ?? "") : "";

            // created_at - check member exists and value is not null/empty
            if (obj.has_member("created_at")) {
                var created_str = obj.get_string_member("created_at");
                if (created_str != null && created_str.length > 0) {
                    user.created_at = new DateTime.from_iso8601(created_str, new TimeZone.utc());
                }
            }

            // updated_at (optional) - check member exists, is not null, and has value
            if (obj.has_member("updated_at")) {
                var member = obj.get_member("updated_at");
                if (member != null && member.get_node_type() == Json.NodeType.VALUE) {
                    var updated_str = obj.get_string_member("updated_at");
                    if (updated_str != null && updated_str.length > 0) {
                        user.updated_at = new DateTime.from_iso8601(updated_str, new TimeZone.utc());
                    }
                }
            }

            // permissions (array of strings) - check member exists and is array
            if (obj.has_member("permissions")) {
                var member = obj.get_member("permissions");
                if (member != null && member.get_node_type() == Json.NodeType.ARRAY) {
                    var perms_array = obj.get_array_member("permissions");
                    if (perms_array != null) {
                        foreach (var perm in perms_array.get_elements()) {
                            var perm_str = perm.get_string();
                            if (perm_str != null) {
                                user.permissions.add(perm_str);
                            }
                        }
                    }
                }
            }

            // app_data (object with string values) - check member exists and is object
            if (obj.has_member("app_data")) {
                var member = obj.get_member("app_data");
                if (member != null && member.get_node_type() == Json.NodeType.OBJECT) {
                    var app_data_obj = obj.get_object_member("app_data");
                    if (app_data_obj != null) {
                        foreach (var key in app_data_obj.get_members()) {
                            var value = app_data_obj.get_string_member(key);
                            user.app_data.set(key, value ?? "");
                        }
                    }
                }
            }

            return user;
        }

        public Json.Object to_json() {
            var obj = new Json.Object();

            // Use null coalescing to ensure we never pass null to set_string_member
            obj.set_string_member("id", id ?? "");
            obj.set_string_member("username", username ?? "");
            obj.set_string_member("email", email ?? "");
            obj.set_string_member("password_hash", password_hash ?? "");
            obj.set_string_member("created_at", created_at != null ? created_at.format_iso8601() : new DateTime.now_utc().format_iso8601());

            // updated_at (optional)
            if (updated_at != null) {
                obj.set_string_member("updated_at", ((!)updated_at).format_iso8601());
            } else {
                obj.set_null_member("updated_at");
            }

            // permissions array - always create array even if empty
            var perms_array = new Json.Array();
            if (permissions != null) {
                foreach (var perm in permissions) {
                    if (perm != null) {
                        perms_array.add_string_element(perm);
                    }
                }
            }
            obj.set_array_member("permissions", perms_array);

            // app_data object - always create object even if empty
            var app_data_obj = new Json.Object();
            if (app_data != null) {
                var iter = app_data.iterator();
                while (iter.next()) {
                    var pair = iter.get();
                    app_data_obj.set_string_member(pair.key ?? "", pair.value ?? "");
                }
            }
            obj.set_object_member("app_data", app_data_obj);

            return obj;
        }
    }
}