###############################################################################
# Suppressing some functions messages because they only output the information
# on how much time they took.
###############################################################################

###############################################################################
# Setup test data frames
###############################################################################

# One key
df1 <- data.frame(key = c(1, 1, 1, 2, 2, 2),
                  a   = c("a", "a", "a", "a", "a", "a"))

df2 <- data.frame(key = c(2, 3),
                  b   = c("b", "b"))

df3 <- data.frame(key = c(1, 2),
                  c   = c("c", "c"))

# Multiple same keys
df1b <- data.frame(key1 = c(1, 1, 1, 2, 2, 2),
                   key2 = c("a", "a", "a", "a", "a", "a"),
                   a    = c("a", "a", "a", "a", "a", "a"))

df2b <- data.frame(key1 = c(2, 3),
                   key2 = c("a", "a"),
                   b    = c("b", "b"))

# Multiple different keys
df1c <- data.frame(key1 = c(1, 1, 1, 2, 2, 2),
                   key2 = c("a", "a", "a", "a", "a", "a"),
                   a    = c("a", "a", "a", "a", "a", "a"))

df2c <- data.frame(var1 = c(2, 3),
                   var2 = c("a", "a"),
                   b    = c("b", "b"))

df3c <- data.frame(any  = c(1, 2),
                   name = c("a", "a"),
                   c    = c("c", "c"))

###############################################################################
# Successful joins
###############################################################################

test_that("Test all basic joins with one key", {
    join_methods <- c("left", "right", "inner", "full", "outer", "left_inner", "right_inner")
    joined_data  <- list()

    for (method in seq_along(join_methods)){
        joined_data[[method]] <- suppressMessages(
            multi_join(list(df1, df2),
                       on  = "key",
                       how = join_methods[[method]],
                       keep_indicators = TRUE))
    }

    expect_equal(length(joined_data), 7)
})


test_that("Join on multiple keys", {
    left_joined <- suppressMessages(multi_join(list(df1b, df2b), on = c("key1", "key2")))

    expect_true("b" %in% names(left_joined))
})


test_that("Join more than two data frames", {
    multiple_joined <- suppressMessages(multi_join(list(df1, df2, df3), on = "key"))

    expect_true(all(c("b", "c") %in% names(multiple_joined)))
})

test_that("Join multiple data frames on different variable names", {
    multiple_joined <- suppressMessages(
        multi_join(list(df1c, df2c, df3c),
                   on = list(df1c = c("key1", "key2"),
                             df2c = c("var1", "var2"),
                             df3c = c("any", "name"))))

    expect_true(all(c("b", "c") %in% names(multiple_joined)))
})


test_that("Warning on invalid join method", {
    expect_message(left_joined <- multi_join(list(df1, df2), on = "key", how = "test"), " ! WARNING: No valid join method provided, 'left' will be used.")

    expect_true("b" %in% names(left_joined))
})


test_that("Note on too many join methods provided", {
    expect_message(left_joined <- multi_join(list(df1, df2),
                                             on  = "key",
                                             how = c("left", "right")), " ~ NOTE: Too many join methods given in 'how'. Excess methods will remain unused.")

    expect_true("b" %in% names(left_joined))
})

###############################################################################
# Abort checks
###############################################################################

test_that("Abort join, if data frames aren't provided as list", {
    expect_message(left_joined <- multi_join(c(df1, df2), on = "key"), " X ERROR: Data frames must be provided as a list. Join will be aborted.")
})


test_that("Abort join, if only one data frames provided", {
    expect_message(left_joined <- multi_join(list(df1), on = "key"), " X ERROR: At least two data frames are required. Join will be aborted.")
})


test_that("Abort join, if 'on' variables are provided as unnamed list", {
    expect_message(left_joined <- multi_join(list(df1, df2), on = list("key")), " X ERROR: If all data frames have the same variable names for the 'on' variables")
})


test_that("Abort join, if 'on' variables are not provided for every data frame", {
    expect_message(multiple_joined <-
                       multi_join(list(df1c, df2c, df3c),
                                  on = list(df1c = c("key1", "key2"),
                                            df2c = c("var1", "var2"))), " X ERROR: Length of 'on' doesn't match the number of provided data frames. Join will be aborted.")
})


test_that("Abort join, if 'on' variables are missing in data frame (equal names)", {
    expect_message(left_joined <- multi_join(list(df1, df2), on = "var"), " X ERROR: Not all 'on' variables")
})


test_that("Abort join, if 'on' variables are missing in data frame (unequal names)", {
    expect_message(multiple_joined <-
                       multi_join(list(df1c, df2c, df3c),
                                  on = list(df1c = c("var1", "key2"),
                                            df2c = c("var1", "var2"),
                                            df3c = c("any", "name"))), " X ERROR: Not all 'on' variables")
})


test_that("Abort join, if second of following data frame doesn't consist of only unique values (equal names)", {
    expect_message(left_joined <- multi_join(list(df1, df1), on = "key"), " X ERROR: The second and all following data frames need to have unique combinations")
})


test_that("Abort join, if second of following data frame doesn't consist of only unique values  (unequal names)", {
    expect_message(multiple_joined <-
                       multi_join(list(df1c, df1c, df3c),
                                  on = list(df1c = c("key1", "key2"),
                                            df1c = c("key1", "key2"),
                                            df3c = c("any", "name"))), " X ERROR: The second and all following data frames need to have unique combinations")
})


test_that("Abort join, if 'on' variables have unequal length", {
    expect_message(multiple_joined <- multi_join(list(df1c, df2c, df3c),
                                  on = list(df1c = c("key1", "key2"),
                                            df2c = c("var1"),
                                            df3c = c("any", "name"))), " X ERROR: Unequal number of 'on' variables provided")
})