import { BasicCommandParser, CommandParser } from '../client/parser';
import { RESP_TYPES } from '../RESP/decoder';
import { UnwrapReply, ArrayReply, BlobStringReply, BooleanReply, CommandArguments, DoubleReply, NullReply, NumberReply, RedisArgument, TuplesReply, MapReply, TypeMapping, Command } from '../RESP/types';

export function isNullReply(reply: unknown): reply is NullReply {
  return reply === null;
}

export function isArrayReply(reply: unknown): reply is ArrayReply<unknown> {
  return Array.isArray(reply);
}

export const transformBooleanReply = {
  2: (reply: NumberReply<0 | 1>) => reply as unknown as UnwrapReply<typeof reply> === 1,
  3: undefined as unknown as () => BooleanReply
};

export const transformBooleanArrayReply = {
  2: (reply: ArrayReply<NumberReply<0 | 1>>) => {
    return (reply as unknown as UnwrapReply<typeof reply>).map(transformBooleanReply[2]);
  },
  3: undefined as unknown as () => ArrayReply<BooleanReply>
};

export type BitValue = 0 | 1;

export function transformDoubleArgument(num: number): string {
  switch (num) {
    case Infinity:
      return '+inf';

    case -Infinity:
      return '-inf';

    default:
      return num.toString();
  }
}

export function transformStringDoubleArgument(num: RedisArgument | number): RedisArgument {
  if (typeof num !== 'number') return num;

  return transformDoubleArgument(num);
}

export const transformDoubleReply = {
  2: (reply: BlobStringReply, preserve?: any, typeMapping?: TypeMapping): DoubleReply => {
    const double = typeMapping ? typeMapping[RESP_TYPES.DOUBLE] : undefined;
    
    switch (double) {
      case String: {
        return reply as unknown as DoubleReply;
      }
      default: {
        let ret: number;

        switch (reply.toString()) {
          case 'inf':
          case '+inf':
            ret = Infinity;
      
          case '-inf':
            ret = -Infinity;
    
          case 'nan':
            ret = NaN;
      
          default:
            ret = Number(reply);
        }

        return ret as unknown as DoubleReply;
      }
    }
  },
  3: undefined as unknown as () => DoubleReply
};

export function createTransformDoubleReplyResp2Func(preserve?: any, typeMapping?: TypeMapping) {
  return (reply: BlobStringReply) => {
    return transformDoubleReply[2](reply, preserve, typeMapping);
  }
}

export const transformDoubleArrayReply = {
  2: (reply: Array<BlobStringReply>, preserve?: any, typeMapping?: TypeMapping) => {
    return reply.map(createTransformDoubleReplyResp2Func(preserve, typeMapping));
  },
  3: undefined as unknown as () => ArrayReply<DoubleReply>
}

export function createTransformNullableDoubleReplyResp2Func(preserve?: any, typeMapping?: TypeMapping) {
  return (reply: BlobStringReply | NullReply) => {
    return transformNullableDoubleReply[2](reply, preserve, typeMapping);
  }
}

export const transformNullableDoubleReply = {
  2: (reply: BlobStringReply | NullReply, preserve?: any, typeMapping?: TypeMapping) => {
    if (reply === null) return null;
  
    return transformDoubleReply[2](reply as BlobStringReply, preserve, typeMapping);
  },
  3: undefined as unknown as () => DoubleReply | NullReply
};

export interface Stringable {
  toString(): string;
}

export function transformTuplesToMap<T>(
  reply: UnwrapReply<ArrayReply<any>>,
  func: (elem: any) => T,
) {
  const message = Object.create(null);

  for (let i = 0; i < reply.length; i+= 2) {
    message[reply[i].toString()] = func(reply[i + 1]);
  }

  return message;
}

export function createTransformTuplesReplyFunc<T extends Stringable>(preserve?: any, typeMapping?: TypeMapping) {
  return (reply: ArrayReply<T>) => {
    return transformTuplesReply<T>(reply, preserve, typeMapping);
  };
}

export function transformTuplesReply<T extends Stringable>(
  reply: ArrayReply<T>,
  preserve?: any,
  typeMapping?: TypeMapping
): MapReply<T , T> {
  const mapType = typeMapping ? typeMapping[RESP_TYPES.MAP] : undefined;

  const inferred = reply as unknown as UnwrapReply<typeof reply>

  switch (mapType) {
    case Array: {
      return reply as unknown as MapReply<T, T>;
    }
    case Map: {
      const ret = new Map<string, BlobStringReply>;

      for (let i = 0; i < inferred.length; i += 2) {
        ret.set(inferred[i].toString(), inferred[i + 1] as any);
      }

      return ret as unknown as MapReply<T, T>;;
    }
    default: {
      const ret: Record<string, BlobStringReply> = Object.create(null);

      for (let i = 0; i < inferred.length; i += 2) {
        ret[inferred[i].toString()] = inferred[i + 1] as any;
      }

      return ret as unknown as MapReply<T, T>;;
    }
  }
}

export interface SortedSetMember {
  value: RedisArgument;
  score: number;
}

export type SortedSetSide = 'MIN' | 'MAX';

export const transformSortedSetReply = {
  2: (reply: ArrayReply<BlobStringReply>, preserve?: any, typeMapping?: TypeMapping) => {
    const inferred = reply as unknown as UnwrapReply<typeof reply>,
      members = [];
    for (let i = 0; i < inferred.length; i += 2) {
      members.push({
        value: inferred[i],
        score: transformDoubleReply[2](inferred[i + 1], preserve, typeMapping)
      });
    }

    return members;
  },
  3: (reply: ArrayReply<TuplesReply<[BlobStringReply, DoubleReply]>>) => {
    return (reply as unknown as UnwrapReply<typeof reply>).map(member => {
      const [value, score] = member as unknown as UnwrapReply<typeof member>;
      return {
        value,
        score
      };
    });
  }
}

export type ListSide = 'LEFT' | 'RIGHT';

export function transformEXAT(EXAT: number | Date): string {
  return (typeof EXAT === 'number' ? EXAT : Math.floor(EXAT.getTime() / 1000)).toString();
}

export function transformPXAT(PXAT: number | Date): string {
  return (typeof PXAT === 'number' ? PXAT : PXAT.getTime()).toString();
}

export interface EvalOptions {
  keys?: Array<string>;
  arguments?: Array<string>;
}

export function evalFirstKeyIndex(options?: EvalOptions): string | undefined {
  return options?.keys?.[0];
}

export function pushEvalArguments(args: Array<string>, options?: EvalOptions): Array<string> {
  if (options?.keys) {
    args.push(
      options.keys.length.toString(),
      ...options.keys
    );
  } else {
    args.push('0');
  }

  if (options?.arguments) {
    args.push(...options.arguments);
  }

  return args;
}

export function pushVariadicArguments(args: CommandArguments, value: RedisVariadicArgument): CommandArguments {
  if (Array.isArray(value)) {
    // https://github.com/redis/node-redis/pull/2160
    args = args.concat(value);
  } else {
    args.push(value);
  }

  return args;
}

export function pushVariadicNumberArguments(
  args: CommandArguments,
  value: number | Array<number>
): CommandArguments {
  if (Array.isArray(value)) {
    for (const item of value) {
      args.push(item.toString());
    }
  } else {
    args.push(value.toString());
  }

  return args;
}

export type RedisVariadicArgument = RedisArgument | Array<RedisArgument>;

export function pushVariadicArgument(
  args: Array<RedisArgument>,
  value: RedisVariadicArgument
): CommandArguments {
  if (Array.isArray(value)) {
    args.push(value.length.toString(), ...value);
  } else {
    args.push('1', value);
  }

  return args;
}

export function   parseOptionalVariadicArgument(
  parser: CommandParser,
  name: RedisArgument,
  value?: RedisVariadicArgument
) {
  if (value === undefined) return;

  parser.push(name);

  parser.pushVariadicWithLength(value);
}

export enum CommandFlags {
  WRITE = 'write', // command may result in modifications
  READONLY = 'readonly', // command will never modify keys
  DENYOOM = 'denyoom', // reject command if currently out of memory
  ADMIN = 'admin', // server admin command
  PUBSUB = 'pubsub', // pubsub-related command
  NOSCRIPT = 'noscript', // deny this command from scripts
  RANDOM = 'random', // command has random results, dangerous for scripts
  SORT_FOR_SCRIPT = 'sort_for_script', // if called from script, sort output
  LOADING = 'loading', // allow command while database is loading
  STALE = 'stale', // allow command while replica has stale data
  SKIP_MONITOR = 'skip_monitor', // do not show this command in MONITOR
  ASKING = 'asking', // cluster related - accept even if importing
  FAST = 'fast', // command operates in constant or log(N) time. Used for latency monitoring.
  MOVABLEKEYS = 'movablekeys' // keys have no pre-determined position. You must discover keys yourself.
}

export enum CommandCategories {
  KEYSPACE = '@keyspace',
  READ = '@read',
  WRITE = '@write',
  SET = '@set',
  SORTEDSET = '@sortedset',
  LIST = '@list',
  HASH = '@hash',
  STRING = '@string',
  BITMAP = '@bitmap',
  HYPERLOGLOG = '@hyperloglog',
  GEO = '@geo',
  STREAM = '@stream',
  PUBSUB = '@pubsub',
  ADMIN = '@admin',
  FAST = '@fast',
  SLOW = '@slow',
  BLOCKING = '@blocking',
  DANGEROUS = '@dangerous',
  CONNECTION = '@connection',
  TRANSACTION = '@transaction',
  SCRIPTING = '@scripting'
}

export type CommandRawReply = [
  name: string,
  arity: number,
  flags: Array<CommandFlags>,
  firstKeyIndex: number,
  lastKeyIndex: number,
  step: number,
  categories: Array<CommandCategories>
];

export type CommandReply = {
  name: string,
  arity: number,
  flags: Set<CommandFlags>,
  firstKeyIndex: number,
  lastKeyIndex: number,
  step: number,
  categories: Set<CommandCategories>
};

export function transformCommandReply(
  this: void,
  [name, arity, flags, firstKeyIndex, lastKeyIndex, step, categories]: CommandRawReply
): CommandReply {
  return {
    name,
    arity,
    flags: new Set(flags),
    firstKeyIndex,
    lastKeyIndex,
    step,
    categories: new Set(categories)
  };
}

export enum RedisFunctionFlags {
  NO_WRITES = 'no-writes',
  ALLOW_OOM = 'allow-oom',
  ALLOW_STALE = 'allow-stale',
  NO_CLUSTER = 'no-cluster'
}

export type FunctionListRawItemReply = [
  'library_name',
  string,
  'engine',
  string,
  'functions',
  Array<[
    'name',
    string,
    'description',
    string | null,
    'flags',
    Array<RedisFunctionFlags>
  ]>
];

export interface FunctionListItemReply {
  libraryName: string;
  engine: string;
  functions: Array<{
    name: string;
    description: string | null;
    flags: Array<RedisFunctionFlags>;
  }>;
}

export function transformFunctionListItemReply(reply: FunctionListRawItemReply): FunctionListItemReply {
  return {
    libraryName: reply[1],
    engine: reply[3],
    functions: reply[5].map(fn => ({
      name: fn[1],
      description: fn[3],
      flags: fn[5]
    }))
  };
}

export interface SlotRange {
  start: number;
  end: number;
}

function parseSlotRangeArguments(
  parser: CommandParser,
  range: SlotRange
): void {
  parser.push(
    range.start.toString(),
    range.end.toString()
  );
}

export function parseSlotRangesArguments(
  parser: CommandParser,
  ranges: SlotRange | Array<SlotRange>
) {
  if (Array.isArray(ranges)) {
    for (const range of ranges) {
      parseSlotRangeArguments(parser, range);
    }
  } else {
    parseSlotRangeArguments(parser, ranges);
  }
}

export type RawRangeReply = [
  start: number,
  end: number
];

export interface RangeReply {
  start: number;
  end: number;
}

export function transformRangeReply([start, end]: RawRangeReply): RangeReply {
  return {
    start,
    end
  };
}

export type ZKeyAndWeight = {
  key: RedisArgument;
  weight: number;
};

export type ZVariadicKeys<T> = T | [T, ...Array<T>];

export type ZKeys = ZVariadicKeys<RedisArgument> | ZVariadicKeys<ZKeyAndWeight>;

export function parseZKeysArguments(
  parser: CommandParser,
  keys: ZKeys
) {
  if (Array.isArray(keys)) {
    parser.push(keys.length.toString());

    if (keys.length) {
      if (isPlainKeys(keys)) {
        parser.pushKeys(keys);
      } else {
        for (let i = 0; i < keys.length; i++) {
          parser.pushKey(keys[i].key)
        }
        parser.push('WEIGHTS');
        for (let i = 0; i < keys.length; i++) {
          parser.push(transformDoubleArgument(keys[i].weight));
        }
      }
    }
  } else {
    parser.push('1');

    if (isPlainKey(keys)) {
      parser.pushKey(keys);
    } else {
      parser.pushKey(keys.key);
      parser.push('WEIGHTS', transformDoubleArgument(keys.weight));
    }
  }
}

function isPlainKey(key: RedisArgument | ZKeyAndWeight): key is RedisArgument {
  return typeof key === 'string' || key instanceof Buffer;
}

function isPlainKeys(keys: Array<RedisArgument> | Array<ZKeyAndWeight>): keys is Array<RedisArgument> {
  return isPlainKey(keys[0]);
}

export type Tail<T extends unknown[]> = T extends [infer Head, ...infer Tail] ? Tail : never;

/**
 * @deprecated
 */
export function parseArgs(command: Command, ...args: Array<any>): CommandArguments {
  const parser = new BasicCommandParser();
  command.parseCommand!(parser, ...args);

  const redisArgs: CommandArguments = parser.redisArgs;
  if (parser.preserve) {
    redisArgs.preserve = parser.preserve;
  }
  return redisArgs;
}

export type StreamMessageRawReply = TuplesReply<[
  id: BlobStringReply,
  message: ArrayReply<BlobStringReply>
]>;

export type StreamMessageReply = {
  id: BlobStringReply,
  message: MapReply<BlobStringReply | string, BlobStringReply>,
};

export function transformStreamMessageReply(typeMapping: TypeMapping | undefined, reply: StreamMessageRawReply): StreamMessageReply {
  const [ id, message ] = reply as unknown as UnwrapReply<typeof reply>;
  return {
    id: id,
    message: transformTuplesReply(message, undefined, typeMapping)
  };
}

export function transformStreamMessageNullReply(typeMapping: TypeMapping | undefined, reply: StreamMessageRawReply | NullReply) {
  return isNullReply(reply) ? reply : transformStreamMessageReply(typeMapping, reply);
}

export type StreamMessagesReply = Array<StreamMessageReply>;

export type StreamsMessagesReply = Array<{
  name: BlobStringReply | string;
  messages: StreamMessagesReply;
}> | null;

export function transformStreamMessagesReply(
  r: ArrayReply<StreamMessageRawReply>,
  typeMapping?: TypeMapping
): StreamMessagesReply {
  const reply = r as unknown as UnwrapReply<typeof r>;

  return reply.map(transformStreamMessageReply.bind(undefined, typeMapping));
}

type StreamMessagesRawReply = TuplesReply<[name: BlobStringReply, ArrayReply<StreamMessageRawReply>]>;
type StreamsMessagesRawReply2 = ArrayReply<StreamMessagesRawReply>;

export function transformStreamsMessagesReplyResp2(
  reply: UnwrapReply<StreamsMessagesRawReply2 | NullReply>,
  preserve?: any,
  typeMapping?: TypeMapping
): StreamsMessagesReply | NullReply { 
  // FUTURE: resposne type if resp3 was working, reverting to old v4 for now
  //: MapReply<BlobStringReply | string, StreamMessagesReply> | NullReply {
  if (reply === null) return null as unknown as NullReply;

  switch (typeMapping? typeMapping[RESP_TYPES.MAP] : undefined) {
/* FUTURE: a response type for when resp3 is working properly
    case Map: {
      const ret = new Map<string, StreamMessagesReply>();

      for (let i=0; i < reply.length; i++) {
        const stream = reply[i] as unknown as UnwrapReply<StreamMessagesRawReply>;
    
        const name = stream[0];
        const rawMessages = stream[1];
    
        ret.set(name.toString(), transformStreamMessagesReply(rawMessages, typeMapping));
      }
    
      return ret as unknown as MapReply<string, StreamMessagesReply>;
    }
    case Array: {
      const ret: Array<BlobStringReply | StreamMessagesReply> = [];

      for (let i=0; i < reply.length; i++) {
        const stream = reply[i] as unknown as UnwrapReply<StreamMessagesRawReply>;
    
        const name = stream[0];
        const rawMessages = stream[1];
    
        ret.push(name); 
        ret.push(transformStreamMessagesReply(rawMessages, typeMapping));
      }

      return ret as unknown as MapReply<string, StreamMessagesReply>;
    }
    default: {
      const ret: Record<string, StreamMessagesReply> = Object.create(null);

      for (let i=0; i < reply.length; i++) {
        const stream = reply[i] as unknown as UnwrapReply<StreamMessagesRawReply>;
    
        const name = stream[0] as unknown as UnwrapReply<BlobStringReply>;
        const rawMessages = stream[1];
    
        ret[name.toString()] = transformStreamMessagesReply(rawMessages);
      }
    
      return ret as unknown as MapReply<string, StreamMessagesReply>;
    }
*/
    // V4 compatible response type
    default: {
      const ret: StreamsMessagesReply = [];

      for (let i=0; i < reply.length; i++) {
        const stream = reply[i] as unknown as UnwrapReply<StreamMessagesRawReply>;

        ret.push({
          name: stream[0],
          messages: transformStreamMessagesReply(stream[1])
        });
      }

      return ret;
    }
  }
}

type StreamsMessagesRawReply3 = MapReply<BlobStringReply, ArrayReply<StreamMessageRawReply>>;

export function transformStreamsMessagesReplyResp3(reply: UnwrapReply<StreamsMessagesRawReply3 | NullReply>): MapReply<BlobStringReply, StreamMessagesReply> | NullReply {
  if (reply === null) return null as unknown as NullReply;
  
  if (reply instanceof Map) {
    const ret = new Map<string, StreamMessagesReply>();

    for (const [n, rawMessages] of reply) {
      const name = n as unknown as UnwrapReply<BlobStringReply>;

      ret.set(name.toString(), transformStreamMessagesReply(rawMessages));
    }

    return ret as unknown as MapReply<BlobStringReply, StreamMessagesReply>
  } else if (reply instanceof Array) {
    const ret = [];

    for (let i=0; i < reply.length; i += 2) {
      const name = reply[i] as BlobStringReply;
      const rawMessages = reply[i+1] as ArrayReply<StreamMessageRawReply>;

      ret.push(name);
      ret.push(transformStreamMessagesReply(rawMessages));
    }

    return ret as unknown as MapReply<BlobStringReply, StreamMessagesReply>
  } else {
    const ret = Object.create(null);
    for (const [name, rawMessages] of Object.entries(reply)) {
      ret[name] = transformStreamMessagesReply(rawMessages);
    }

    return ret as unknown as MapReply<BlobStringReply, StreamMessagesReply>
  }
}