## git2r, R bindings to the libgit2 library.
## Copyright (C) 2013-2017 The git2r contributors
##
## This program is free software; you can redistribute it and/or modify
## it under the terms of the GNU General Public License, version 2,
## as published by the Free Software Foundation.
##
## git2r is distributed in the hope that it will be useful,
## but WITHOUT ANY WARRANTY; without even the implied warranty of
## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
## GNU General Public License for more details.
##
## You should have received a copy of the GNU General Public License along
## with this program; if not, write to the Free Software Foundation, Inc.,
## 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.

library(git2r)

## For debugging
sessionInfo()

## Create a directory in tempdir
path <- tempfile(pattern="git2r-")
dir.create(path)

## Initialize a repository
repo <- init(path)
config(repo, user.name="Alice", user.email="alice@example.org")

## Create a file, add, commit
writeLines("Hello world!", file.path(path, "test.txt"))
add(repo, "test.txt")
commit(repo, "Commit message")

## Change the file, diff between index and workdir
writeLines("Hello again!\nHere is a second line\nAnd a third",
           file.path(path, "test.txt"))
diff_1 <- diff(repo)
diff(repo, as_char=TRUE)
diff(repo, as_char=TRUE, filename = file.path(path, "test.diff"))

stopifnot(identical(diff_1@old, "index"))
stopifnot(identical(diff_1@new, "workdir"))
stopifnot(identical(length(diff_1@files), 1L))
stopifnot(identical(diff_1@files[[1]]@old_file, "test.txt"))
stopifnot(identical(diff_1@files[[1]]@new_file, "test.txt"))
stopifnot(identical(length(diff_1@files[[1]]@hunks), 1L))
stopifnot(identical(length(diff_1@files[[1]]@hunks[[1]]@lines), 4L))
## TODO: check actual diff

## Diff between index and HEAD is empty
diff_2 <- diff(repo, index=TRUE)
diff(repo, as_char=TRUE)
diff(repo, as_char=TRUE, filename = file.path(path, "test.diff"))

stopifnot(identical(diff_2@old, "HEAD"))
stopifnot(identical(diff_2@new, "index"))
stopifnot(identical(diff_2@files, list()))

## Diff between tree and working dir, same as diff_1
diff_3 <- diff(tree(commits(repo)[[1]]))
diff(repo, as_char=TRUE)
diff(repo, as_char=TRUE, filename = file.path(path, "test.diff"))

stopifnot(identical(diff_3@old, tree(commits(repo)[[1]])))
stopifnot(identical(diff_3@new, "workdir"))
stopifnot(identical(diff_3@files, diff_1@files))

## Add changes, diff between index and HEAD is the same as diff_1
add(repo, "test.txt")
diff_4 <- diff(repo, index=TRUE)
diff(repo, as_char=TRUE)
diff(repo, as_char=TRUE, filename = file.path(path, "test.diff"))

stopifnot(identical(diff_4@old, "HEAD"))
stopifnot(identical(diff_4@new, "index"))
stopifnot(identical(diff_4@files, diff_1@files))

## Diff between tree and index
diff_5 <- diff(tree(commits(repo)[[1]]), index=TRUE)
diff(repo, as_char=TRUE)
diff(repo, as_char=TRUE, filename = file.path(path, "test.diff"))

stopifnot(identical(diff_5@old, tree(commits(repo)[[1]])))
stopifnot(identical(diff_5@new, "index"))
stopifnot(identical(diff_5@files, diff_1@files))

## Diff between two trees
commit(repo, "Second commit")
tree_1 <- tree(commits(repo)[[2]])
tree_2 <- tree(commits(repo)[[1]])
diff_6 <- diff(tree_1, tree_2)
diff(repo, as_char=TRUE)
diff(repo, as_char=TRUE, filename = file.path(path, "test.diff"))

stopifnot(identical(diff_6@old, tree_1))
stopifnot(identical(diff_6@new, tree_2))
stopifnot(identical(diff_6@files, diff_1@files))

## Length of a diff
stopifnot(identical(length(diff_1), 1L))
stopifnot(identical(length(diff_2), 0L))
stopifnot(identical(length(diff_3), 1L))
stopifnot(identical(length(diff_4), 1L))
stopifnot(identical(length(diff_5), 1L))
stopifnot(identical(length(diff_6), 1L))

## Binary files
set.seed(42)
writeBin(as.raw((sample(0:255, 1000, replace=TRUE))),
         con=file.path(path, "test.bin"))
add(repo, "test.bin")
diff_7 <- diff(repo, index=TRUE)
diff(repo, as_char=TRUE)
diff(repo, as_char=TRUE, filename = file.path(path, "test.diff"))

stopifnot(any(grepl("binary file", capture.output(summary(diff_7)))))

## TODO: errors
## Check non-logical index argument
res <- tools::assertError(
                  .Call(git2r:::git2r_diff, NULL, NULL, NULL, "FALSE", NULL))
stopifnot(length(grep("Error in 'git2r_diff': 'index' must be logical vector of length one with non NA value\n",
                      res[[1]]$message)) > 0)

## Check various combinations of diff arguments
res <- tools::assertError(
                  .Call(git2r:::git2r_diff, NULL, NULL, tree(commits(repo)[[1]]), FALSE, NULL))
stopifnot(length(grep("Error in 'git2r_diff': Invalid diff parameters",
                      res[[1]]$message)) > 0)

res <- tools::assertError(
                  .Call(git2r:::git2r_diff, NULL, NULL, tree(commits(repo)[[1]]), TRUE, NULL))
stopifnot(length(grep("Error in 'git2r_diff': Invalid diff parameters",
                      res[[1]]$message)) > 0)

res <- tools::assertError(
                  .Call(git2r:::git2r_diff, repo, tree(commits(repo)[[1]]), NULL, FALSE, NULL))
stopifnot(length(grep("Error in 'git2r_diff': Invalid diff parameters",
                      res[[1]]$message)) > 0)

res <- tools::assertError(
                  .Call(git2r:::git2r_diff, repo, tree(commits(repo)[[1]]), NULL, TRUE, NULL))
stopifnot(length(grep("Error in 'git2r_diff': Invalid diff parameters",
                      res[[1]]$message)) > 0)

res <- tools::assertError(
                  .Call(git2r:::git2r_diff, repo, tree(commits(repo)[[1]]), tree(commits(repo)[[2]]), FALSE, NULL))
stopifnot(length(grep("Error in 'git2r_diff': Invalid diff parameters",
                      res[[1]]$message)) > 0)

res <- tools::assertError(
                  .Call(git2r:::git2r_diff, repo, tree(commits(repo)[[1]]), tree(commits(repo)[[2]]), TRUE, NULL))
stopifnot(length(grep("Error in 'git2r_diff': Invalid diff parameters",
                      res[[1]]$message)) > 0)

## TODO: printing

## Cleanup
unlink(path, recursive=TRUE)
