otl_base_url <- function(dev = FALSE) {
  if (dev) {
    return("devapi.opentreeoflife.org")
  }
  "api.opentreeoflife.org"
}

otl_url <- function(dev = FALSE) {
  paste0("https://", otl_base_url(dev))
}

otl_version <- function(version) {
  if (missing(version)) {
    return("v3")
  } else {
    return(version)
  }
}

##' @importFrom rlang interrupt
is_otl_online <- function(dev = FALSE) {
  is_online <- !is.null(curl::nslookup(otl_base_url(dev), error = FALSE))
  if (!is_online) {
    message("No internet connection or the Open Tree of Life's API is down.")
    rlang::interrupt()
  }
}

# Take a request object and return list (if JSON) or plain text (if another
# type)
##' @importFrom httr content
##' @importFrom jsonlite fromJSON
otl_parse <- function(req) {
  if (grepl("application/json", req[["headers"]][["content-type"]])) {
    return(jsonlite::fromJSON(httr::content(req, "text", encoding = "UTF-8"), simplifyVector = FALSE))
  }
  txt <- httr::content(req, as = "text", encoding = "UTF-8")
  if (identical(txt, "")) {
    stop("No output to parse; check your query.", call. = FALSE)
  }
  txt
}

otl_check_error <- function(cont) {
  if (is.list(cont)) {
    if (exists("description", cont)) {
      if (exists("Error", cont$description)) {
        stop(paste("Error: ", cont$description$error, "\n", sep = ""))
      } else if (exists("message", cont)) {
        stop(paste("Message: ", cont$descrption$message, "\n", sep = ""))
      }
    }
  }
}

## Check and parse result of query
##' @importFrom rlang interrupt
otl_check <- function(req) {
  early_stop <- function(m) {
    message(m)
    rlang::interrupt()
  }
  tryCatch({
    if (!req$status_code < 400) {
      msg <- otl_parse(req)
      stop("HTTP failure: ", req$status_code, "\n", msg, call. = FALSE)
    }
    desc <- otl_parse(req)
    otl_check_error(desc)
    desc
  },
  error = function(e) early_stop(e), 
  warning = function(w) early_stop(w)
  )
}

##' @importFrom httr GET
otl_GET <- function(path, url = otl_url(...), otl_v = otl_version(...), ...) {
  is_otl_online()
  req <- httr::GET(url, path = paste(otl_v, path, sep = "/"), ...)
  otl_check(req)
}

##' @importFrom jsonlite toJSON
##' @importFrom httr POST
otl_POST <- function(path, body, url = otl_url(...), otl_v = otl_version(...), ...) {
  is_otl_online()
  stopifnot(is.list(body))

  body_json <- ifelse(length(body), jsonlite::toJSON(body), "")

  req <- httr::POST(url,
    path = paste(otl_v, path, sep = "/"),
    body = body_json, ...
  )
  otl_check(req)
}

otl_formats <- function(format) {
  switch(tolower(format),
    "nexus" = ".nex",
    "newick" = ".tre",
    "nexml" = ".nexml",
    "json" = ".json",
    ""
  ) # fall through is no extension = nex(j)son
}

## Strip all characters except the ottId from a OpenTree label (internal or terminal)
otl_ottid_from_label <- function(label) {
  return(as.numeric(gsub("(.+[ _]ott)([0-9]+)", "\\2", label)))
}

##' @importFrom rncl read_newick_phylo
phylo_from_otl <- function(res, dedup = FALSE) {
  if (is.list(res)) {
    if (!is.null(res$newick)) {
      tree <- res$newick
    } else if (!is.null(res$subtree)) {
      tree <- res$subtree
    } else {
      stop("Cannot find tree")
    }
  } else if (is.character(res)) {
    tree <- res
  } else {
    stop("I don't know how to deal with this format.")
  }
  if (grepl("\\(", tree)) {
    fnm <- tempfile()
    cat(tree, file = fnm)
    if (!dedup) {
      phy <- rncl::read_newick_phylo(fnm)
    } else {
      dedup_tr <- deduplicate_labels(fnm)
      phy <- rncl::read_newick_phylo(dedup_tr)
      unlink(dedup_tr)
    }
    unlink(fnm)
  } else {
    phy <- tree_to_labels(tree)$tip_label
  }
  return(phy)
}

nexml_from_otl <- function(res) {
  if (!requireNamespace("RNeXML", quietly = TRUE)) {
    stop("The RNeXML package is needed to use the nexml file format")
  }
  fnm <- tempfile()
  cat(res, file = fnm)
  phy <- RNeXML::nexml_read(x = fnm)
  unlink(fnm)
  phy
}

## check if the argument provided looks like a number (can be coerced
## to integer/numeric).
check_numeric <- function(x) {
  if (is.null(x)) {
    return(FALSE)
  }
  if (length(x) != 1) {
    stop("only 1 element should be provided")
  }
  if (!is.numeric(x)) {
    x <- as.character(x)
    if (any(is.na(x))) {
      return(FALSE)
    }
    return(grepl("^[0-9]+$", x))
  } else {
    return(x %% 1 == 0)
  }
}

## Check that ott_ids are not NULL, not NAs and look like numbers
check_ott_ids <- function(ott_ids) {
  if (!is.null(ott_ids)) {
    if (inherits(ott_ids, "otl_ott_id")) {
      ## convert objects returned by ott_id method to a vector
      ott_ids <- unlist(ott_ids)
    }
    if (any(is.na(ott_ids))) {
      stop("NAs are not allowed")
    }
    if (!all(sapply(ott_ids, check_numeric))) {
      stop(sQuote("ott_ids"), " must look like numbers.")
    }
  } else {
    stop("You must supply some OTT ids.")
  }
  ott_ids
}

## all nodes have a node_id (character, e.g. "ott12345" or "mrcaott123ott456")
check_valid_node_id <- function(x) {
  if (length(x) != 1) {
    stop("only 1 element should be provided")
  }
  if (!is.character(x)) {
    return(FALSE)
  }
  if (grepl("^mrcaott\\d+ott\\d+", x) || grepl("^ott\\d+", x)) {
    return(TRUE)
  } else {
    return(FALSE)
  }
}

check_node_ids <- function(node_ids) {
  if (!is.null(node_ids)) {
    if (!is.character(node_ids)) {
      stop("Argument ", sQuote("node_ids"), " must be of type character.")
    }
    if (any(is.na(node_ids))) {
      stop("NAs are not allowed")
    }
    if (!all(sapply(node_ids, check_valid_node_id))) {
      stop(sQuote("node_ids"), " must look like \'ott123\' or \'mrcaott123ott456\'.")
    }
  }
}

# node labels for tree_of_life subtree and induced_subtree
# might also be useful for taxonomy queries
check_label_format <- function(x) {
  if (x %in% c("name", "id", "name_and_id")) {
    return(TRUE)
  } else {
    return(FALSE)
  }
}