rank_cocoso <- function (df, weights_cocoso, alpha=0.5)
{
  alternatives <- df[3:nrow(df), 1]
  alternatives <- as.data.frame(alternatives)
  colnames(alternatives) <- "Alternatives"
  weights_decisor <- as.numeric(df[2, 2:ncol(df)])
  criteria_direction <- df[1, 2:ncol(df)]
  criterias <- colnames(df)[2:ncol(df)]
  matrix_decis <- as.data.frame(df[3:nrow(df), 2:ncol(df)])
  colnames(matrix_decis) <- criterias
  matrix_decis <- matrix_decis %>% mutate_all(as.numeric)
  matrix_decis_norm <- matrix_decis # Inicializar matrix_decis_norm
  weights_cocoso <- as.numeric(weights_cocoso)

  seq_pond <- rep(0,nrow(matrix_decis))
  seq_exp <- rep(0,nrow(matrix_decis))
  ka <- kb <- kc <- CoCoSo <- rep(0,nrow(matrix_decis))
  matrix_decis_norm <- matrix_decis
  # Normalizacao da Matriz de Decisao do CoCoSo
  for(j in 1:ncol(matrix_decis)) {
    for(i in 1:nrow(matrix_decis)) {
      if(criteria_direction[j]=="MAX") {
        matrix_decis_norm[i,j] <- (matrix_decis[i,j] - min(matrix_decis[,j])) /
          (max(matrix_decis[,j]) - min(matrix_decis[,j]))
      } else {
        matrix_decis_norm[i,j] <- (max(matrix_decis[,j]) - matrix_decis[i,j]) /
          (max(matrix_decis[,j]) - min(matrix_decis[,j]))
      }
    }
  } # fim da normalizacao da matriz de decisao do CoCoSo
  # Sequencias de Comparabilidade
  for(i in 1:nrow(matrix_decis_norm)) {
    for(j in 1:ncol(matrix_decis_norm)) {
      seq_pond[i] <- seq_pond[i] + weights_cocoso[j] * matrix_decis_norm[i,j]
      seq_exp[i] <- seq_exp[i] + (matrix_decis_norm[i,j]) ^ weights_cocoso[j]
    }
  }
  # Estrategias de Agregacao e Agregacao Final
  for(i in 1:nrow(matrix_decis_norm)) {
    ka[i] <- (seq_pond[i] + seq_exp[i]) / (sum(seq_pond) + sum(seq_exp))
    kb[i] <- seq_pond[i] / min(seq_pond) + seq_exp[i] / min(seq_exp)
    kc[i] <- (alpha * seq_pond[i] + (1 - alpha) * seq_exp[i]) /
      (alpha * max(seq_pond) + (1 - alpha) * max(seq_exp))
    CoCoSo[i] <- (ka[i] * kb[i] * kc[i])^(1/3) + (1/3) * (ka[i] + kb[i] + kc[i])
  }
  rank_COCOSO <- matrix_decis %>%
    mutate(Alternatives = alternatives, CoCoSo = CoCoSo) %>%
    arrange(desc(CoCoSo)) %>%
    mutate(Position = row_number()) %>%
    select(Alternatives, Position, everything())
  rank_COCOSO <- cbind(rank_COCOSO, ka = ka, kb = kb, kc = kc)
  colnames(rank_COCOSO[,1]) <- "Alternatives"

  return(rank_COCOSO)
}