using Inversion;
using Spry;
using Spry.Authentication;
using Statum;
using ClankerSaddle.Services;

namespace ClankerSaddle {

    /** Sealed capability id carried by {@link DeleteCapabilityAction}. */
    public class CapabilityActionPrivate : Object {
        public int64 capability_id { get; set; }
    }

    /** Sealed saddle-capability attachment identity. */
    public class SaddleCapabilityActionPrivate : Object {
        public int64 saddle_id { get; set; }
        public int64 link_id { get; set; }
    }

    /** Sealed task-capability attachment identity. */
    public class TaskCapabilityActionPrivate : Object {
        public int64 task_id { get; set; }
        public int64 link_id { get; set; }
    }

    /**
     * Creates a capability (tag) from the saddles page's capabilities
     * section; names are unique.
     */
    public class CreateCapabilityAction : StatumAction {

        private CapabilityService capabilities = inject<CapabilityService>();
        private UserService users = inject<UserService>();

        public override async DirectiveBuilder handle() throws GLib.Error {
            // The roles decision: capabilities are admin-managed (the
            // catalogue feeds the dispatcher's routing).
            var guard = yield SpryAuth.require_permission(directives(), request, users,
                SpryAuth.ADMIN_PERMISSION, "/login");
            if (guard != null) {
                return (!)guard;
            }

            string name = Forms.field(request, "name");
            if (name.length == 0) {
                return directives().notify("error", "A capability name is required").navigate("/saddles");
            }

            try {
                var capability = yield capabilities.create_capability(name);
                return directives().notify("success", @"Capability '$(capability.name)' created")
                    .navigate("/saddles");
            } catch (Error e) {
                return directives().notify("error", @"Could not create the capability: $(e.message)")
                    .navigate("/saddles");
            }
        }
    }

    /**
     * Deletes a capability everywhere (saddles stop carrying it, tasks
     * stop requiring it); the id is sealed.
     */
    public class DeleteCapabilityAction : TypedStatumAction<CapabilityActionPrivate> {

        private CapabilityService capabilities = inject<CapabilityService>();
        private UserService users = inject<UserService>();

        protected override Type private_type { get { return typeof(CapabilityActionPrivate); } }

        public override async DirectiveBuilder handle() throws GLib.Error {
            // The roles decision: capabilities are admin-managed.
            var guard = yield SpryAuth.require_permission(directives(), request, users,
                SpryAuth.ADMIN_PERMISSION, "/login");
            if (guard != null) {
                return (!)guard;
            }

            var ctx = request_private;
            if (ctx == null) {
                return directives().navigate("/saddles");
            }

            try {
                yield capabilities.delete_capability(((!)ctx).capability_id);
                return directives().notify("success", "Capability deleted").navigate("/saddles");
            } catch (Error e) {
                return directives().notify("error", @"Could not delete the capability: $(e.message)")
                    .navigate("/saddles");
            }
        }
    }

    /**
     * Attaches the form-selected capability to the sealed saddle; the
     * saddle card's capability chips.
     */
    public class AttachSaddleCapabilityAction : TypedStatumAction<SaddleActionPrivate> {

        private CapabilityService capabilities = inject<CapabilityService>();
        private UserService users = inject<UserService>();

        protected override Type private_type { get { return typeof(SaddleActionPrivate); } }

        public override async DirectiveBuilder handle() throws GLib.Error {
            var guard = yield SpryAuth.require_login(directives(), request, users);
            if (guard != null) {
                return (!)guard;
            }

            var ctx = request_private;
            int64 saddle_id = ctx != null ? ((!)ctx).saddle_id : Forms.integer(request, "saddle_id", 0);
            int64 capability_id = Forms.integer(request, "capability_id", 0);
            if (saddle_id <= 0 || capability_id <= 0) {
                return directives().notify("error", "Pick a capability to attach").navigate("/saddles");
            }

            try {
                yield capabilities.attach_to_saddle(capability_id, saddle_id);
                return directives().notify("success", "Capability attached").navigate("/saddles");
            } catch (Error e) {
                return directives().notify("error", @"Could not attach the capability: $(e.message)")
                    .navigate("/saddles");
            }
        }
    }

    /** Detaches a saddle capability; both ids are sealed. */
    public class DetachSaddleCapabilityAction : TypedStatumAction<SaddleCapabilityActionPrivate> {

        private CapabilityService capabilities = inject<CapabilityService>();
        private UserService users = inject<UserService>();

        protected override Type private_type { get { return typeof(SaddleCapabilityActionPrivate); } }

        public override async DirectiveBuilder handle() throws GLib.Error {
            var guard = yield SpryAuth.require_login(directives(), request, users);
            if (guard != null) {
                return (!)guard;
            }

            var ctx = request_private;
            if (ctx == null) {
                return directives().navigate("/saddles");
            }

            try {
                yield capabilities.detach_from_saddle(((!)ctx).link_id);
                return directives().notify("success", "Capability removed").navigate("/saddles");
            } catch (Error e) {
                return directives().notify("error", @"Could not remove the capability: $(e.message)")
                    .navigate("/saddles");
            }
        }
    }

    /**
     * True when the task's required capabilities are still editable:
     * in draft, or queued before any worker has the job. Once a
     * saddle is assigned (or the task is parked on one) the pairing
     * the dispatcher negotiated is locked, and terminal tasks lock
     * everything.
     */
    private static async bool task_capabilities_editable(TaskService tasks, int64 task_id)
            throws GLib.Error {
        var detail = yield tasks.get_task(task_id);
        if (detail == null) {
            return false;
        }
        string status = ((!)detail).task.status;
        return status == STATUS_DRAFT || status == STATUS_QUEUED;
    }

    /**
     * Attaches the form-selected capability to the sealed task as a
     * required capability; the task page's capabilities section. Only
     * editable while the task is draft or queued (before a worker has
     * the job).
     */
    public class AttachTaskCapabilityAction : SealedTaskAction {

        private CapabilityService capability_service = inject<CapabilityService>();
        private TaskService task_service = inject<TaskService>();
        private UserService users = inject<UserService>();

        public override async DirectiveBuilder handle() throws GLib.Error {
            var guard = yield SpryAuth.require_login(directives(), request, users);
            if (guard != null) {
                return (!)guard;
            }

            int64 task_id = sealed_task_id();
            int64 capability_id = Forms.integer(request, "capability_id", 0);
            if (task_id <= 0 || capability_id <= 0) {
                return directives().notify("error", "Pick a capability to require")
                    .navigate(@"/tasks/$(task_id)");
            }
            if (!(yield task_capabilities_editable(task_service, task_id))) {
                return directives().notify("error",
                        "Capabilities are locked once a worker has the job")
                    .navigate(@"/tasks/$(task_id)");
            }

            try {
                yield capability_service.attach_to_task(capability_id, task_id);
                return directives().notify("success", "Capability required")
                    .navigate(@"/tasks/$(task_id)");
            } catch (Error e) {
                return directives().notify("error", @"Could not attach the capability: $(e.message)")
                    .navigate(@"/tasks/$(task_id)");
            }
        }
    }

    /** Detaches a task's required capability; both ids are sealed. */
    public class DetachTaskCapabilityAction : TypedStatumAction<TaskCapabilityActionPrivate> {

        private CapabilityService capabilities = inject<CapabilityService>();
        private TaskService task_service = inject<TaskService>();
        private UserService users = inject<UserService>();

        protected override Type private_type { get { return typeof(TaskCapabilityActionPrivate); } }

        public override async DirectiveBuilder handle() throws GLib.Error {
            var guard = yield SpryAuth.require_login(directives(), request, users);
            if (guard != null) {
                return (!)guard;
            }

            var ctx = request_private;
            if (ctx == null) {
                return directives().navigate("/tasks");
            }
            if (!(yield task_capabilities_editable(task_service, ((!)ctx).task_id))) {
                return directives().notify("error",
                        "Capabilities are locked once a worker has the job")
                    .navigate(@"/tasks/$(((!)ctx).task_id)");
            }

            try {
                yield capabilities.detach_from_task(((!)ctx).link_id);
                return directives().notify("success", "Requirement removed")
                    .navigate(@"/tasks/$(((!)ctx).task_id)");
            } catch (Error e) {
                return directives().notify("error", @"Could not remove the requirement: $(e.message)")
                    .navigate(@"/tasks/$(((!)ctx).task_id)");
            }
        }
    }
}