# A function that passes all checks in .check_sim_args but returns an error
# message if the supplied arguments are invalid
.check_sim_args_default <- function(...) {
  default_args <- list(
    n_chains = 10,
    statistic = "size",
    offspring_dist = rpois,
    stat_threshold = 10,
    pop = 10,
    percent_immune = 0.1
  )
  # Modify the default arguments with the user's arguments
  new_args <- modifyList(
    default_args,
    list(...)
  )
  # Run the check_sim_args function and capture the output
  out <- tryCatch(
    expr = {
      do.call(
        .check_sim_args,
        new_args
      )
    },
    error = function(e) {
      stop(e)
    }
  )
  # Return the output
  return(out)
}

# A function that passes all checks in `.check_time_args` but returns an error
# message if the supplied arguments are invalid
.check_time_args_default <- function(...) {
  default_args <- list(
    t0 = 0,
    tf_specified = FALSE, # tf is not specified but default tf = Inf below
    tf = Inf,
    generation_time = NULL
  )
  new_args <- modifyList(
    default_args,
    list(...)
  )
  out <- tryCatch(
    expr = {
      do.call(
        .check_time_args,
        new_args
      )
    },
    error = function(e) {
      stop(e)
    }
  )
  return(out)
}


test_that("Smaller checker functions work", {
  expect_error(
    .check_offspring_func_valid(rrpois),
    "not found"
  )
  expect_error(
    .check_generation_time_valid("a"),
    "Must be a function"
  )
  expect_error(
    .check_generation_time_valid(function(x) rep("a", 10)),
    "numeric"
  )
  expect_error(
    .check_generation_time_valid(function(x) 3),
    "Must have length"
  )
  expect_no_error(
    .check_statistic_args(
      statistic = "size",
      stat_threshold = 10
    )
  )
})

test_that(".check_sim_args() returns errors", {
  # Checks with .check_sim_args
  expect_no_error(
    .check_sim_args_default()
  )
  # n_chains must be >= 1
  expect_error(
    .check_sim_args_default(
      n_chains = 0
    ),
    "Must be >= 1."
  )
  # statistic can only be "size" or "length"
  expect_error(
    .check_sim_args_default(
      statistic = "duration"
    ),
    "Must be element of set \\{'size','length'\\}"
  )
  # offspring_dist must be a function
  expect_error(
    .check_sim_args_default(
      offspring_dist = "rpois"
    ),
    "Must be a function, not 'character'"
  )
  # offspring_dist must be a known function (in the environment)
  expect_error(
    .check_sim_args_default(
      offspring_dist = r
    ),
    "object 'r' not found"
  )
  # stat_threshold must be >= 1
  expect_error(
    .check_sim_args_default(
      stat_threshold = 0
    ),
    "Assertion failed."
  )
  # pop cannot be negative
  expect_error(
    .check_sim_args_default(
      pop = -1
    ),
    "Element 1 is not >= 1."
  )
  # percent_immune must be in between 0 and 1
  expect_error(
    .check_sim_args_default(
      percent_immune = 1.1
    ),
    "Element 1 is not <= 1."
  )
})

test_that(".check_time_args() returns errors", {
  # Checks with .check_time_args
  expect_no_error(
    .check_time_args_default()
  )
  # t0 cannot be negative
  expect_error(
    .check_time_args_default(
      t0 = -1
    ),
    "Element 1 is not >= 0."
  )
  # tf cannot be negative
  expect_error(
    .check_time_args_default(
      tf = -1
    ),
    "Element 1 is not >= 0."
  )
  # If tf is specified, generation_time must be specified too
  expect_error(
    .check_time_args_default(
      tf_specified = TRUE,
      tf = 10
    ),
    "If `tf` is specified, `generation_time` must be specified too."
  )
})