package mindustry.annotations;

import java.lang.annotation.*;

public class Annotations{
    //region entity interfaces

    /** Indicates that a method overrides other methods. */
    @Target({ElementType.METHOD})
    @Retention(RetentionPolicy.SOURCE)
    public @interface Replace{}

    /** Indicates that a method should be final in all implementing classes. */
    @Target({ElementType.METHOD})
    @Retention(RetentionPolicy.SOURCE)
    public @interface Final{}

    /** Indicates that a field will be interpolated when synced. */
    @Target({ElementType.FIELD})
    @Retention(RetentionPolicy.SOURCE)
    public @interface SyncField{
        /** If true, the field will be linearly interpolated. If false, it will be interpolated as an angle. */
        boolean value();
        /** If true, the field is clamped to 0-1. */
        boolean clamped() default false;
    }

    /** Indicates that a field will not be read from the server when syncing the local player state. */
    @Target({ElementType.FIELD})
    @Retention(RetentionPolicy.SOURCE)
    public @interface SyncLocal{}

    /** Indicates that a field should not be synced to clients (but may still be non-transient) */
    @Target({ElementType.FIELD})
    @Retention(RetentionPolicy.SOURCE)
    public @interface NoSync{}

    /** Indicates that a field should be synced, but not serialized */
    @Target({ElementType.FIELD})
    @Retention(RetentionPolicy.SOURCE)
    public @interface NoSerialize{}

    /** Indicates that a component field is imported from other components. This means it doesn't actually exist. */
    @Target({ElementType.FIELD})
    @Retention(RetentionPolicy.SOURCE)
    public @interface Import{}

    /** Indicates that a component field is read-only. */
    @Target({ElementType.FIELD, ElementType.METHOD})
    @Retention(RetentionPolicy.SOURCE)
    public @interface ReadOnly{
    }

    /** Indicates multiple inheritance on a component type. */
    @Target(ElementType.TYPE)
    @Retention(RetentionPolicy.SOURCE)
    public @interface Component{
        /** Whether to generate a base class for this components.
         * An entity cannot have two base classes, so only one component can have base be true. */
        boolean base() default false;
        /** Whether to generate a proper interface for this component class. */
        boolean genInterface() default true;
    }

    /** Indicates that a method is implemented by the annotation processor. */
    @Target(ElementType.METHOD)
    @Retention(RetentionPolicy.SOURCE)
    public @interface InternalImpl{
    }

    /** Indicates priority of a method in an entity. Methods with higher priority are done last. */
    @Target(ElementType.METHOD)
    @Retention(RetentionPolicy.SOURCE)
    public @interface MethodPriority{
        float value();
    }

    /** Indicates that a component def is present on all entities. */
    @Target(ElementType.TYPE)
    @Retention(RetentionPolicy.SOURCE)
    public @interface BaseComponent{
    }

    /** Creates a group that only examines entities that have all the components listed. */
    @Retention(RetentionPolicy.SOURCE)
    public @interface GroupDef{
        Class[] value();
        Class[] exclude() default {};
        boolean collide() default false;
        boolean spatial() default false;
        boolean mapping() default false;
        boolean update() default false;
    }

    /** Indicates an entity definition. */
    @Retention(RetentionPolicy.SOURCE)
    public @interface EntityDef{
        /** List of component interfaces */
        Class[] value();
        /** Whether the class is final */
        boolean isFinal() default true;
        /** If true, entities are recycled. */
        boolean pooled() default false;
        /** Whether to serialize (makes the serialize method return this value).
         * If true, this entity is automatically put into save files.
         * If false, no serialization code is generated at all. */
        boolean serialize() default true;
        /** Whether to generate IO code. This is for advanced usage only. */
        boolean genio() default true;
        /** Whether I made a massive mistake by merging two different class branches */
        boolean legacy() default false;
        /** Groups to exclude. */
        String[] excludeGroups() default {};
    }

    /** Indicates an internal interface for entity components. */
    @Target(ElementType.TYPE)
    @Retention(RetentionPolicy.SOURCE)
    public @interface EntityInterface{}

    //endregion
    //region misc. utility

    /** Automatically loads block regions annotated with this. */
    @Target(ElementType.FIELD)
    @Retention(RetentionPolicy.SOURCE)
    public @interface Load{
        /**
         * The region name to load. Variables can be used:
         * "@" -> block name
         * "@size" -> block size
         * "#" "#1" "#2" -> index number, for arrays
         * */
        String value();
        /** 1D Array length, if applicable.  */
        int length() default 1;
        /** 2D array lengths. */
        int[] lengths() default {};
        /** Fallback string used to replace "@" (the block name) if the region isn't found. */
        String fallback() default "error";
    }

    /** Registers a statement for auto serialization. */
    @Target(ElementType.TYPE)
    @Retention(RetentionPolicy.SOURCE)
    public @interface RegisterStatement{
        String value();
    }

    @Target(ElementType.TYPE)
    @Retention(RetentionPolicy.SOURCE)
    public @interface StyleDefaults{
    }

    /** Indicates that a method should always call its super version. */
    @Target(ElementType.METHOD)
    @Retention(RetentionPolicy.SOURCE)
    public @interface CallSuper{}

    /** Annotation that allows overriding CallSuper annotation. To be used on method that overrides method with CallSuper annotation from parent class. */
    @Target(ElementType.METHOD)
    @Retention(RetentionPolicy.SOURCE)
    public @interface OverrideCallSuper{}

    //endregion
    //region struct

    /** Marks a class as a special value type struct. Class name must end in 'Struct'. */
    @Target(ElementType.TYPE)
    @Retention(RetentionPolicy.SOURCE)
    public @interface Struct{}

    /** Marks a field of a struct. Optional. */
    @Target(ElementType.FIELD)
    @Retention(RetentionPolicy.SOURCE)
    public @interface StructField{
        /** Size of a struct field in bits. Not valid on booleans or floating point numbers. */
        int value();
    }

    //endregion
    //region remote

    public enum PacketPriority{
        /** Does not get handled unless client is connected. */
        low,
        /** Gets put in a queue and processed if not connected. */
        normal,
        /** Gets handled immediately, regardless of connection status. */
        high,
    }

    /** A set of two booleans, one specifying server and one specifying client. */
    public enum Loc{
        /** Server only. */
        server(true, false),
        /** Client only. */
        client(false, true),
        /** Both server and client. */
        both(true, true),
        /** Neither server nor client. */
        none(false, false);

        public final boolean isServer;
        public final boolean isClient;

        Loc(boolean server, boolean client){
            this.isServer = server;
            this.isClient = client;
        }
    }

    public enum Variant{
        /** Method can only be invoked targeting one player. */
        one(true, false),
        /** Method can only be invoked targeting all players. */
        all(false, true),
        /** Method targets both one player and all players. */
        both(true, true);

        public final boolean isOne, isAll;

        Variant(boolean isOne, boolean isAll){
            this.isOne = isOne;
            this.isAll = isAll;
        }
    }

    /** Marks a method as invokable remotely across a server/client connection. */
    @Target(ElementType.METHOD)
    @Retention(RetentionPolicy.SOURCE)
    public @interface Remote{
        /** Specifies the locations from which this method can cause remote invocations (This -> Remote) [Default: Server -> Client]. */
        Loc targets() default Loc.server;

        /** Specifies which methods are generated. Only affects server-to-client methods (Server -> Client(s)) [Default: Server -> Client & Server -> All Clients]. */
        Variant variants() default Variant.all;

        /** The locations where this method is called locally, when invoked locally (This -> This) [Default: No local invocations]. */
        Loc called() default Loc.none;

        /** Whether the server should forward this packet to all other clients upon receival from a client (Client -> Server -> Other Clients). [Default: Don't Forward Client Invocations] */
        boolean forward() default false;

        /**
         * Whether the packet for this method is sent with UDP instead of TCP.
         * UDP is faster, but is prone to packet loss and duplication.
         */
        boolean unreliable() default false;

        /** Priority of this event. */
        PacketPriority priority() default PacketPriority.normal;
    }

    @Target(ElementType.TYPE)
    @Retention(RetentionPolicy.SOURCE)
    public @interface TypeIOHandler{ }

    //endregion
}
