dat <- data.frame(
  rel = c(1:6, NA, 7, 8),
  period = c(1, 1, 1, 1, 1, 2, 2, 2, 2),
  ea = c("11", "11", "12", "12", "13", "11", "12", "11", "14")
)

pias <- as_aggregation_structure(
  data.frame(level1 = 1, level2 = c(11, 12, 13, 14), weight = 1)
)

epr <- elementary_index(dat, rel ~ period + ea, contrib = TRUE)
epr2 <- elementary_index(dat, rel ~ period + ea)

index <- aggregate(epr, pias)

res <- c(
  1.41421356237309,
  3.46410161513775,
  5,
  NaN,
  6.48074069840786,
  NaN,
  NaN,
  8
)

# head and tail work.
local({
  expect_equal(head(epr, 1), epr[1])
  expect_equal(head(epr, 5), epr)
  expect_equal(head(epr, -1), epr[1:3])
  expect_equal(tail(epr, 1), epr[4])
  expect_equal(tail(epr, 5), epr)
  expect_equal(tail(epr, -1), epr[2:4])
  expect_equal(head(epr, 2:1), epr[1:2, 1])
  expect_equal(tail(epr, 2:1), epr[3:4, 2])
  expect_equal(head(epr, c(NA, -1)), epr[, 1])
  expect_equal(tail(epr, c(NA, -1)), epr[, 2])
  # #72
  expect_equal(head(epr2, c(1, 1)), epr2[1, 1])
  expect_equal(tail(epr2, c(1, 1)), epr2[4, 2])
})

# Subscripting methods work.
local({
  expect_equal(epr[], epr)
  expect_equal(index[1:5], index)
  expect_equal(
    epr[c(TRUE, FALSE, TRUE, TRUE), 2:1],
    elementary_index(
      dat,
      rel ~ factor(period, 2:1) + factor(ea, c(11, 13:14)),
      contrib = TRUE
    )
  )
  expect_equal(
    epr[c("14", "12"), TRUE],
    elementary_index(dat, rel ~ period + factor(ea, c(14, 12)), contrib = TRUE)
  )
  expect_equal(epr[matrix(c(1, 2, 1, 2), 2)], list(epr[1, 1], epr[2, 2]))
  expect_equal(epr[matrix(0, 2, 2)], list())
})

# Subscripting methods give errors where expected.
local({
  expect_error(epr[1, NA])
  expect_error(epr[1, 3])
  expect_error(epr[c(1, 2, 1), ])
  expect_error(epr[, NULL])
  expect_error(epr[integer(0)])
  expect_error(epr[NA])
  expect_error(epr[matrix(c(-1, 2), 1, 2)])
})

# Replacement methods work with an index.
local({
  # No op
  expect_equal(replace(epr, 1:4, epr), epr)
  expect_equal(replace(epr, integer(0), epr[1]), epr)
  expect_equal(replace(epr, matrix(0, 2, 2), epr[1]), epr)
  # Adds contributions
  expect_equal(replace(epr2, 1:4, epr), epr)
  # Removes contributions
  expect_equal(replace(epr, 1:4, epr2), set_contrib(epr2, value = numeric(0)))

  epr3 <- epr2
  epr3[c(TRUE, FALSE), 2] <- epr[1, 1]
  expect_equal(
    as.matrix(epr3),
    replace(as.matrix(epr), matrix(c(1, 3, 2, 2), 2), as.numeric(epr[1, 1]))
  )
  expect_equal(contrib(epr3, "13")[, 2], contrib(epr)[, 1])

  # Index doesn't recycle like a matrix
  m <- as.matrix(epr3)
  epr3[c(1, 1, 2, 2)] <- epr[1:2]
  m[1, ] <- as.matrix(epr)[2, ]
  expect_equal(as.matrix(epr3), m)
  expect_equal(contrib(epr3), contrib(epr, "12"))
  epr3[c(1, 1, 2, 2)] <- as.matrix(epr[1:2])
  expect_false(isTRUE(all.equal(as.matrix(epr3), m)))

  # Errors
  expect_error(epr[1:2] <- epr[, 1])
  expect_error(epr[1:3] <- epr[1:2])
  expect_error(epr[NA] <- epr[1])
  expect_error(epr[, NA] <- epr[1])
  expect_error(epr[1] <- chain(epr[1]))
  epr <- chain(epr)
  expect_error(epr[1] <- epr2[1])
  expect_error(epr[matrix(c(1, 2), 1)] <- unchain(epr[1, 1]))
})

# Replacement methods work with a vector.
local({
  epr[, 1] <- 1
  expect_equal(
    as.matrix(epr),
    matrix(
      c(1, 1, 1, 1, res[5:8]),
      4,
      2,
      dimnames = list(levels = 11:14, time = 1:2)
    )
  )
  expect_equal(
    contrib(epr),
    matrix(
      c(0, 0, 2.5962965079607, 2.88444419044716),
      2,
      2,
      dimnames = list(product = c("11.1", "11.2"), time = 1:2)
    )
  )

  epr[1, c(FALSE, TRUE)] <- "2"
  expect_equal(
    as.matrix(epr),
    matrix(
      c(1, 1, 1, 1, 2, res[6:8]),
      4,
      2,
      dimnames = list(levels = 11:14, time = 1:2)
    )
  )
  expect_equal(
    contrib(epr),
    matrix(0, 0, 2, dimnames = list(product = NULL, time = 1:2))
  )

  # recycling should still happen
  epr2[1:3, ] <- 8:9
  expect_equal(
    epr2[1:3, ],
    as_index(matrix(8:9, 3, 2, dimnames = list(levels = 11:13, time = 1:2)))
  )

  epr[1, c(1, 2, 1)] <- setNames(1:3, letters[1:3])
  expect_equal(
    epr[1, ],
    set_contrib(
      as_index(matrix(3:2, 1, dimnames = list(levels = "11", time = 1:2))),
      value = numeric(0)
    )
  )

  epr["14"] <- 1
  expect_equal(
    as.matrix(epr),
    matrix(
      c(3, 1, 1, 1, 2, res[6:7], 1),
      4,
      2,
      dimnames = list(levels = 11:14, time = 1:2)
    )
  )
  expect_equal(
    contrib(epr, "14"),
    matrix(0, 0, 2, dimnames = list(product = NULL, time = 1:2))
  )

  # Replacing nothing
  epr2 <- epr
  suppressWarnings(epr[FALSE] <- "a")
  expect_identical(epr, epr2)

  suppressWarnings(epr[1, 0] <- "a")
  expect_identical(epr, epr2)

  # Errors
  expect_error(epr[1] <- 1:3)
  expect_error(epr[1:2] <- 1:3)
  expect_error(epr[NA] <- 1)
  expect_error(epr[1, NA] <- 1)
  expect_error(epr[1, c(TRUE, FALSE, FALSE)] <- 1)
  expect_error(epr[5] <- 1)
  expect_error(epr[1] <- numeric(0))
  expect_warning(epr[c(TRUE, FALSE, TRUE), ])
})

# Replacement method works with a matrix.
local({
  epr3 <- replace(epr, is.na(epr), 1:3)
  expect_equal(
    as.matrix(epr3),
    replace(as.matrix(epr), c(4, 6, 7), c(1, 2, 3))
  )

  epr4 <- replace(
    epr3,
    matrix(c("11", "11", "12", "12", "2", "2", "2", "2"), 4),
    1:2
  )
  expect_equal(as.matrix(epr4), replace(as.matrix(epr3), 5:6, 2))

  expect_identical(replace(epr, matrix(FALSE, 4, 2), 0), epr)

  epr5 <- replace(epr3, is.na(epr), epr[1, 1])
  expect_equal(
    as.matrix(epr5),
    replace(as.matrix(epr), c(4, 6, 7), sqrt(2))
  )
  expect_equal(contrib(epr5[4, 1]), contrib(epr[1, 1]))

  # Works when there are no contributions.
  epr5 <- replace(epr2, is.na(epr), epr[1, 1])
  expect_equal(
    as.matrix(epr5),
    replace(as.matrix(epr2), c(4, 6, 7), sqrt(2))
  )
  expect_equal(contrib(epr5[4, 1]), contrib(epr[1, 1]))

  expect_error(replace(epr, matrix(NA, 4, 2), 0))
  expect_error(epr[is.na(epr)] <- numeric(0))
  expect_error(epr[matrix(TRUE, 3, 3)] <- 1)
  expect_error(epr[matrix(1, nrow = 1, ncol = 3)] <- 1)
  expect_warning(epr[is.na(epr)] <- 1:2)
  expect_error(epr[is.na(epr)] <- list(1))
  expect_error(epr[!is.na(epr)] <- epr[1])
})
