// Copyright 2022 The Jujutsu Authors
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// https://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

use std::path::{Path, PathBuf};

use crate::common::TestEnvironment;

#[test]
fn test_unsquash() {
    let test_env = TestEnvironment::default();
    test_env.jj_cmd_ok(test_env.env_root(), &["git", "init", "repo"]);
    let repo_path = test_env.env_root().join("repo");

    test_env.jj_cmd_ok(&repo_path, &["branch", "create", "a"]);
    std::fs::write(repo_path.join("file1"), "a\n").unwrap();
    test_env.jj_cmd_ok(&repo_path, &["new"]);
    test_env.jj_cmd_ok(&repo_path, &["branch", "create", "b"]);
    std::fs::write(repo_path.join("file1"), "b\n").unwrap();
    test_env.jj_cmd_ok(&repo_path, &["new"]);
    test_env.jj_cmd_ok(&repo_path, &["branch", "create", "c"]);
    std::fs::write(repo_path.join("file1"), "c\n").unwrap();
    // Test the setup
    insta::assert_snapshot!(get_log_output(&test_env, &repo_path), @r###"
    @  382c9bad7d42 c
    ○  d5d59175b481 b
    ○  184ddbcce5a9 a
    ◆  000000000000
    "###);

    // Unsquashes into the working copy from its parent by default
    let (stdout, stderr) = test_env.jj_cmd_ok(&repo_path, &["unsquash"]);
    insta::assert_snapshot!(stdout, @"");
    insta::assert_snapshot!(stderr, @r###"
    Working copy now at: mzvwutvl 9177132c c | (no description set)
    Parent commit      : qpvuntsm 184ddbcc a b | (no description set)
    "###);
    insta::assert_snapshot!(get_log_output(&test_env, &repo_path), @r###"
    @  9177132cfbb9 c
    ○  184ddbcce5a9 a b
    ◆  000000000000
    "###);
    let stdout = test_env.jj_cmd_success(&repo_path, &["file", "show", "file1"]);
    insta::assert_snapshot!(stdout, @r###"
    c
    "###);

    // Can unsquash into a given commit from its parent
    test_env.jj_cmd_ok(&repo_path, &["undo"]);
    let (stdout, stderr) = test_env.jj_cmd_ok(&repo_path, &["unsquash", "-r", "b"]);
    insta::assert_snapshot!(stdout, @"");
    insta::assert_snapshot!(stderr, @r###"
    Rebased 1 descendant commits
    Working copy now at: mzvwutvl b353b29c c | (no description set)
    Parent commit      : kkmpptxz 27772b15 b | (no description set)
    "###);
    insta::assert_snapshot!(get_log_output(&test_env, &repo_path), @r###"
    @  b353b29c423d c
    ○  27772b156771 b
    ◆  000000000000 a
    "###);
    let stdout = test_env.jj_cmd_success(&repo_path, &["file", "show", "file1", "-r", "b"]);
    insta::assert_snapshot!(stdout, @r###"
    b
    "###);
    let stdout = test_env.jj_cmd_success(&repo_path, &["file", "show", "file1"]);
    insta::assert_snapshot!(stdout, @r###"
    c
    "###);

    // Cannot unsquash into a merge commit (because it's unclear which parent it
    // should come from)
    test_env.jj_cmd_ok(&repo_path, &["undo"]);
    test_env.jj_cmd_ok(&repo_path, &["edit", "b"]);
    test_env.jj_cmd_ok(&repo_path, &["new"]);
    test_env.jj_cmd_ok(&repo_path, &["branch", "create", "d"]);
    std::fs::write(repo_path.join("file2"), "d\n").unwrap();
    test_env.jj_cmd_ok(&repo_path, &["new", "-m", "merge", "c", "d"]);
    test_env.jj_cmd_ok(&repo_path, &["branch", "create", "e"]);
    insta::assert_snapshot!(get_log_output(&test_env, &repo_path), @r###"
    @    b780e7469252 e
    ├─╮
    │ ○  f86e2b3af3e3 d
    ○ │  382c9bad7d42 c
    ├─╯
    ○  d5d59175b481 b
    ○  184ddbcce5a9 a
    ◆  000000000000
    "###);
    let stderr = test_env.jj_cmd_failure(&repo_path, &["unsquash"]);
    insta::assert_snapshot!(stderr, @r###"
    Error: Cannot unsquash merge commits
    "###);

    // Can unsquash from a merge commit
    test_env.jj_cmd_ok(&repo_path, &["new", "e"]);
    std::fs::write(repo_path.join("file1"), "e\n").unwrap();
    let (stdout, stderr) = test_env.jj_cmd_ok(&repo_path, &["unsquash"]);
    insta::assert_snapshot!(stdout, @"");
    insta::assert_snapshot!(stderr, @r###"
    Working copy now at: pzsxstzt bd05eb69 merge
    Parent commit      : mzvwutvl 382c9bad c e?? | (no description set)
    Parent commit      : xznxytkn f86e2b3a d e?? | (no description set)
    "###);
    insta::assert_snapshot!(get_log_output(&test_env, &repo_path), @r###"
    @    bd05eb698d1e
    ├─╮
    │ ○  f86e2b3af3e3 d e??
    ○ │  382c9bad7d42 c e??
    ├─╯
    ○  d5d59175b481 b
    ○  184ddbcce5a9 a
    ◆  000000000000
    "###);
    let stdout = test_env.jj_cmd_success(&repo_path, &["file", "show", "file1"]);
    insta::assert_snapshot!(stdout, @r###"
    e
    "###);
}

#[test]
fn test_unsquash_partial() {
    let mut test_env = TestEnvironment::default();
    test_env.jj_cmd_ok(test_env.env_root(), &["git", "init", "repo"]);
    let repo_path = test_env.env_root().join("repo");

    test_env.jj_cmd_ok(&repo_path, &["branch", "create", "a"]);
    std::fs::write(repo_path.join("file1"), "a\n").unwrap();
    std::fs::write(repo_path.join("file2"), "a\n").unwrap();
    test_env.jj_cmd_ok(&repo_path, &["new"]);
    test_env.jj_cmd_ok(&repo_path, &["branch", "create", "b"]);
    std::fs::write(repo_path.join("file1"), "b\n").unwrap();
    std::fs::write(repo_path.join("file2"), "b\n").unwrap();
    test_env.jj_cmd_ok(&repo_path, &["new"]);
    test_env.jj_cmd_ok(&repo_path, &["branch", "create", "c"]);
    std::fs::write(repo_path.join("file1"), "c\n").unwrap();
    std::fs::write(repo_path.join("file2"), "c\n").unwrap();
    // Test the setup
    insta::assert_snapshot!(get_log_output(&test_env, &repo_path), @r###"
    @  a0b1a272ebc4 c
    ○  d117da276a0f b
    ○  54d3c1c0e9fd a
    ◆  000000000000
    "###);

    // If we don't make any changes in the diff-editor, the whole change is moved
    // from the parent
    let edit_script = test_env.set_up_fake_diff_editor();
    std::fs::write(&edit_script, "dump JJ-INSTRUCTIONS instrs").unwrap();
    let (stdout, stderr) = test_env.jj_cmd_ok(&repo_path, &["unsquash", "-r", "b", "-i"]);
    insta::assert_snapshot!(stdout, @"");
    insta::assert_snapshot!(stderr, @r###"
    Rebased 1 descendant commits
    Working copy now at: mzvwutvl 8802263d c | (no description set)
    Parent commit      : kkmpptxz 5bd83140 b | (no description set)
    "###);

    insta::assert_snapshot!(
        std::fs::read_to_string(test_env.env_root().join("instrs")).unwrap(), @r###"
    You are moving changes from: qpvuntsm 54d3c1c0 a | (no description set)
    into its child: kkmpptxz d117da27 b | (no description set)

    The diff initially shows the parent commit's changes.

    Adjust the right side until it shows the contents you want to keep in
    the parent commit. The changes you edited out will be moved into the
    child commit. If you don't make any changes, then the operation will be
    aborted.
    "###);

    insta::assert_snapshot!(get_log_output(&test_env, &repo_path), @r###"
    @  8802263dbd92 c
    ○  5bd83140fd47 b
    ○  c93de9257191 a
    ◆  000000000000
    "###);
    let stdout = test_env.jj_cmd_success(&repo_path, &["file", "show", "file1", "-r", "a"]);
    insta::assert_snapshot!(stdout, @r###"
    a
    "###);

    // Can unsquash only some changes in interactive mode
    test_env.jj_cmd_ok(&repo_path, &["undo"]);
    std::fs::write(edit_script, "reset file1").unwrap();
    let (stdout, stderr) = test_env.jj_cmd_ok(&repo_path, &["unsquash", "-i"]);
    insta::assert_snapshot!(stdout, @"");
    insta::assert_snapshot!(stderr, @r###"
    Working copy now at: mzvwutvl a896ffde c | (no description set)
    Parent commit      : kkmpptxz 904111b4 b | (no description set)
    "###);
    insta::assert_snapshot!(get_log_output(&test_env, &repo_path), @r###"
    @  a896ffdebb85 c
    ○  904111b4d3c4 b
    ○  54d3c1c0e9fd a
    ◆  000000000000
    "###);
    let stdout = test_env.jj_cmd_success(&repo_path, &["file", "show", "file1", "-r", "b"]);
    insta::assert_snapshot!(stdout, @r###"
    a
    "###);
    let stdout = test_env.jj_cmd_success(&repo_path, &["file", "show", "file2", "-r", "b"]);
    insta::assert_snapshot!(stdout, @r###"
    b
    "###);
    let stdout = test_env.jj_cmd_success(&repo_path, &["file", "show", "file1", "-r", "c"]);
    insta::assert_snapshot!(stdout, @r###"
    c
    "###);
    let stdout = test_env.jj_cmd_success(&repo_path, &["file", "show", "file2", "-r", "c"]);
    insta::assert_snapshot!(stdout, @r###"
    c
    "###);

    // Try again with --tool=<name>, which implies --interactive
    test_env.jj_cmd_ok(&repo_path, &["undo"]);
    let (stdout, stderr) = test_env.jj_cmd_ok(
        &repo_path,
        &[
            "unsquash",
            "--config-toml=ui.diff-editor='false'",
            "--tool=fake-diff-editor",
        ],
    );
    insta::assert_snapshot!(stdout, @"");
    insta::assert_snapshot!(stderr, @r###"
    Working copy now at: mzvwutvl aaca9268 c | (no description set)
    Parent commit      : kkmpptxz fe8eb117 b | (no description set)
    "###);
    let stdout = test_env.jj_cmd_success(&repo_path, &["file", "show", "file1", "-r", "b"]);
    insta::assert_snapshot!(stdout, @r###"
    a
    "###);
    let stdout = test_env.jj_cmd_success(&repo_path, &["file", "show", "file2", "-r", "b"]);
    insta::assert_snapshot!(stdout, @r###"
    b
    "###);
    let stdout = test_env.jj_cmd_success(&repo_path, &["file", "show", "file1", "-r", "c"]);
    insta::assert_snapshot!(stdout, @r###"
    c
    "###);
    let stdout = test_env.jj_cmd_success(&repo_path, &["file", "show", "file2", "-r", "c"]);
    insta::assert_snapshot!(stdout, @r###"
    c
    "###);
}

fn get_log_output(test_env: &TestEnvironment, repo_path: &Path) -> String {
    let template = r#"commit_id.short() ++ " " ++ branches"#;
    test_env.jj_cmd_success(repo_path, &["log", "-T", template])
}

#[test]
fn test_unsquash_description() {
    let mut test_env = TestEnvironment::default();
    test_env.jj_cmd_ok(test_env.env_root(), &["git", "init", "repo"]);
    let repo_path = test_env.env_root().join("repo");

    let edit_script = test_env.set_up_fake_editor();
    std::fs::write(&edit_script, r#"fail"#).unwrap();

    // If both descriptions are empty, the resulting description is empty
    std::fs::write(repo_path.join("file1"), "a\n").unwrap();
    std::fs::write(repo_path.join("file2"), "a\n").unwrap();
    test_env.jj_cmd_ok(&repo_path, &["new"]);
    std::fs::write(repo_path.join("file1"), "b\n").unwrap();
    std::fs::write(repo_path.join("file2"), "b\n").unwrap();
    test_env.jj_cmd_ok(&repo_path, &["unsquash"]);
    insta::assert_snapshot!(get_description(&test_env, &repo_path, "@"), @"");

    // If the destination's description is empty and the source's description is
    // non-empty, the resulting description is from the source
    test_env.jj_cmd_ok(&repo_path, &["undo"]);
    test_env.jj_cmd_ok(&repo_path, &["describe", "@-", "-m", "source"]);
    test_env.jj_cmd_ok(&repo_path, &["unsquash"]);
    insta::assert_snapshot!(get_description(&test_env, &repo_path, "@"), @r###"
    source
    "###);

    // If the destination description is non-empty and the source's description is
    // empty, the resulting description is from the destination
    test_env.jj_cmd_ok(&repo_path, &["op", "restore", "@--"]);
    test_env.jj_cmd_ok(&repo_path, &["describe", "-m", "destination"]);
    test_env.jj_cmd_ok(&repo_path, &["unsquash"]);
    insta::assert_snapshot!(get_description(&test_env, &repo_path, "@"), @r###"
    destination
    "###);

    // If both descriptions were non-empty, we get asked for a combined description
    test_env.jj_cmd_ok(&repo_path, &["undo"]);
    test_env.jj_cmd_ok(&repo_path, &["describe", "@-", "-m", "source"]);
    std::fs::write(&edit_script, "dump editor0").unwrap();
    test_env.jj_cmd_ok(&repo_path, &["unsquash"]);
    insta::assert_snapshot!(get_description(&test_env, &repo_path, "@"), @r###"
    destination

    source
    "###);
    insta::assert_snapshot!(
        std::fs::read_to_string(test_env.env_root().join("editor0")).unwrap(), @r###"
    JJ: Enter a description for the combined commit.
    JJ: Description from the destination commit:
    destination

    JJ: Description from source commit:
    source

    JJ: Lines starting with "JJ: " (like this one) will be removed.
    "###);

    // If the source's *content* doesn't become empty, then the source remains and
    // both descriptions are unchanged
    test_env.jj_cmd_ok(&repo_path, &["undo"]);
    insta::assert_snapshot!(get_description(&test_env, &repo_path, "@-"), @r###"
    source
    "###);
    insta::assert_snapshot!(get_description(&test_env, &repo_path, "@"), @r###"
    destination
    "###);
}

#[test]
fn test_unsquash_description_editor_avoids_unc() {
    let mut test_env = TestEnvironment::default();
    test_env.jj_cmd_ok(test_env.env_root(), &["git", "init", "repo"]);
    let repo_path = test_env.env_root().join("repo");

    let edit_script = test_env.set_up_fake_editor();
    std::fs::write(repo_path.join("file1"), "a\n").unwrap();
    std::fs::write(repo_path.join("file2"), "a\n").unwrap();
    test_env.jj_cmd_ok(&repo_path, &["new"]);
    std::fs::write(repo_path.join("file1"), "b\n").unwrap();
    std::fs::write(repo_path.join("file2"), "b\n").unwrap();
    test_env.jj_cmd_ok(&repo_path, &["describe", "@-", "-m", "destination"]);
    test_env.jj_cmd_ok(&repo_path, &["describe", "-m", "source"]);

    std::fs::write(edit_script, "dump-path path").unwrap();
    test_env.jj_cmd_ok(&repo_path, &["unsquash"]);

    let edited_path =
        PathBuf::from(std::fs::read_to_string(test_env.env_root().join("path")).unwrap());
    // While `assert!(!edited_path.starts_with("//?/"))` could work here in most
    // cases, it fails when it is not safe to strip the prefix, such as paths
    // over 260 chars.
    assert_eq!(edited_path, dunce::simplified(&edited_path));
}

fn get_description(test_env: &TestEnvironment, repo_path: &Path, rev: &str) -> String {
    test_env.jj_cmd_success(
        repo_path,
        &["log", "--no-graph", "-T", "description", "-r", rev],
    )
}