// 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;

use git2::Oid;

use crate::common::{get_stderr_string, TestEnvironment};

pub mod common;

#[test]
fn test_git_colocated() {
    let test_env = TestEnvironment::default();
    let workspace_root = test_env.env_root().join("repo");
    let git_repo = git2::Repository::init(&workspace_root).unwrap();

    // Create an initial commit in Git
    std::fs::write(workspace_root.join("file"), "contents").unwrap();
    git_repo
        .index()
        .unwrap()
        .add_path(Path::new("file"))
        .unwrap();
    let tree1_oid = git_repo.index().unwrap().write_tree().unwrap();
    let tree1 = git_repo.find_tree(tree1_oid).unwrap();
    let signature = git2::Signature::new(
        "Someone",
        "someone@example.com",
        &git2::Time::new(1234567890, 60),
    )
    .unwrap();
    git_repo
        .commit(
            Some("refs/heads/master"),
            &signature,
            &signature,
            "initial",
            &tree1,
            &[],
        )
        .unwrap();
    insta::assert_snapshot!(
        git_repo.head().unwrap().peel_to_commit().unwrap().id().to_string(),
        @"e61b6729ff4292870702f2f72b2a60165679ef37"
    );

    // Import the repo
    test_env.jj_cmd_success(&workspace_root, &["init", "--git-repo", "."]);
    insta::assert_snapshot!(get_log_output(&test_env, &workspace_root), @r###"
    @ 3e9369cd54227eb88455e1834dbc08aad6a16ac4 
    o e61b6729ff4292870702f2f72b2a60165679ef37 master
    o 0000000000000000000000000000000000000000 
    "###);
    insta::assert_snapshot!(
        git_repo.head().unwrap().peel_to_commit().unwrap().id().to_string(),
        @"e61b6729ff4292870702f2f72b2a60165679ef37"
    );

    // Modify the working copy. The working-copy commit should changed, but the Git
    // HEAD commit should not
    std::fs::write(workspace_root.join("file"), "modified").unwrap();
    insta::assert_snapshot!(get_log_output(&test_env, &workspace_root), @r###"
    @ b26951a9c6f5c270e4d039880208952fd5faae5e 
    o e61b6729ff4292870702f2f72b2a60165679ef37 master
    o 0000000000000000000000000000000000000000 
    "###);
    insta::assert_snapshot!(
        git_repo.head().unwrap().peel_to_commit().unwrap().id().to_string(),
        @"e61b6729ff4292870702f2f72b2a60165679ef37"
    );

    // Create a new change from jj and check that it's reflected in Git
    test_env.jj_cmd_success(&workspace_root, &["new"]);
    insta::assert_snapshot!(get_log_output(&test_env, &workspace_root), @r###"
    @ 9dbb23ff2ff5e66c43880f1042369d704f7a321e 
    o b26951a9c6f5c270e4d039880208952fd5faae5e 
    o e61b6729ff4292870702f2f72b2a60165679ef37 master
    o 0000000000000000000000000000000000000000 
    "###);
    insta::assert_snapshot!(
        git_repo.head().unwrap().target().unwrap().to_string(),
        @"b26951a9c6f5c270e4d039880208952fd5faae5e"
    );
}

#[test]
fn test_git_colocated_export_branches_on_snapshot() {
    // Checks that we export branches that were changed only because the working
    // copy was snapshotted

    let test_env = TestEnvironment::default();
    let workspace_root = test_env.env_root().join("repo");
    let git_repo = git2::Repository::init(&workspace_root).unwrap();
    test_env.jj_cmd_success(&workspace_root, &["init", "--git-repo", "."]);

    // Create branch pointing to the initial commit
    std::fs::write(workspace_root.join("file"), "initial").unwrap();
    test_env.jj_cmd_success(&workspace_root, &["branch", "create", "foo"]);
    insta::assert_snapshot!(get_log_output(&test_env, &workspace_root), @r###"
    @ 438471f3fbf1004298d8fb01eeb13663a051a643 foo
    o 0000000000000000000000000000000000000000 
    "###);

    // The branch gets updated when we modify the working copy, and it should get
    // exported to Git without requiring any other changes
    std::fs::write(workspace_root.join("file"), "modified").unwrap();
    insta::assert_snapshot!(get_log_output(&test_env, &workspace_root), @r###"
    @ fab22d1acf5bb9c5aa48cb2c3dd2132072a359ca foo
    o 0000000000000000000000000000000000000000 
    "###);
    insta::assert_snapshot!(git_repo
        .find_reference("refs/heads/foo")
        .unwrap()
        .target()
        .unwrap()
        .to_string(), @"fab22d1acf5bb9c5aa48cb2c3dd2132072a359ca");
}

#[test]
fn test_git_colocated_rebase_on_import() {
    let test_env = TestEnvironment::default();
    let workspace_root = test_env.env_root().join("repo");
    let git_repo = git2::Repository::init(&workspace_root).unwrap();
    test_env.jj_cmd_success(&workspace_root, &["init", "--git-repo", "."]);

    // Make some changes in jj and check that they're reflected in git
    std::fs::write(workspace_root.join("file"), "contents").unwrap();
    test_env.jj_cmd_success(&workspace_root, &["commit", "-m", "add a file"]);
    std::fs::write(workspace_root.join("file"), "modified").unwrap();
    test_env.jj_cmd_success(&workspace_root, &["branch", "set", "master"]);
    test_env.jj_cmd_success(&workspace_root, &["commit", "-m", "modify a file"]);
    // TODO: We shouldn't need this command here to trigger an import of the
    // refs/heads/master we just exported
    test_env.jj_cmd_success(&workspace_root, &["st"]);

    // Move `master` and HEAD backwards, which should result in commit2 getting
    // hidden, and a new working-copy commit at the new position.
    let commit2_oid = git_repo
        .find_branch("master", git2::BranchType::Local)
        .unwrap()
        .get()
        .target()
        .unwrap();
    let commit2 = git_repo.find_commit(commit2_oid).unwrap();
    let commit1 = commit2.parents().next().unwrap();
    git_repo.branch("master", &commit1, true).unwrap();
    git_repo.set_head("refs/heads/master").unwrap();
    insta::assert_snapshot!(get_log_output(&test_env, &workspace_root), @r###"
    @ 7f96185cfbe36341d0f9a86ebfaeab67a5922c7e 
    o 4bcbeaba9a4b309c5f45a8807fbf5499b9714315 master
    o 0000000000000000000000000000000000000000 
    "###);
}

#[test]
fn test_git_colocated_branches() {
    let test_env = TestEnvironment::default();
    let workspace_root = test_env.env_root().join("repo");
    let git_repo = git2::Repository::init(&workspace_root).unwrap();
    test_env.jj_cmd_success(&workspace_root, &["init", "--git-repo", "."]);
    test_env.jj_cmd_success(&workspace_root, &["new", "-m", "foo"]);
    test_env.jj_cmd_success(&workspace_root, &["new", "@-", "-m", "bar"]);
    insta::assert_snapshot!(get_log_output(&test_env, &workspace_root), @r###"
    @ 3560559274ab431feea00b7b7e0b9250ecce951f 
    | o 1e6f0b403ed2ff9713b5d6b1dc601e4804250cda 
    |/  
    o 230dd059e1b059aefc0da06a2e5a7dbf22362f22 master
    o 0000000000000000000000000000000000000000 
    "###);

    // Create a branch in jj. It should be exported to Git even though it points to
    // the working- copy commit.
    test_env.jj_cmd_success(&workspace_root, &["branch", "set", "master"]);
    insta::assert_snapshot!(
        git_repo.find_reference("refs/heads/master").unwrap().target().unwrap().to_string(),
        @"3560559274ab431feea00b7b7e0b9250ecce951f"
    );
    insta::assert_snapshot!(
        git_repo.head().unwrap().target().unwrap().to_string(),
        @"230dd059e1b059aefc0da06a2e5a7dbf22362f22"
    );

    // Update the branch in Git
    git_repo
        .reference(
            "refs/heads/master",
            Oid::from_str("1e6f0b403ed2ff9713b5d6b1dc601e4804250cda").unwrap(),
            true,
            "test",
        )
        .unwrap();
    insta::assert_snapshot!(get_log_output(&test_env, &workspace_root), @r###"
    Working copy now at: eb08b363bb5e (no description set)
    @ eb08b363bb5ef8ee549314260488980d7bbe8f63 
    | o 1e6f0b403ed2ff9713b5d6b1dc601e4804250cda master
    |/  
    o 230dd059e1b059aefc0da06a2e5a7dbf22362f22 
    o 0000000000000000000000000000000000000000 
    "###);
}

#[test]
fn test_git_colocated_conflicting_git_refs() {
    let test_env = TestEnvironment::default();
    let workspace_root = test_env.env_root().join("repo");
    git2::Repository::init(&workspace_root).unwrap();
    test_env.jj_cmd_success(&workspace_root, &["init", "--git-repo", "."]);
    test_env.jj_cmd_success(&workspace_root, &["branch", "create", "main"]);
    let assert = test_env
        .jj_cmd(&workspace_root, &["branch", "create", "main/sub"])
        .assert()
        .success()
        .stdout("");
    insta::assert_snapshot!(get_stderr_string(&assert), @r###"
    Failed to export some branches:
      main/sub
    Hint: Git doesn't allow a branch name that looks like a parent directory of
    another (e.g. `foo` and `foo/bar`). Try to rename the branches that failed to
    export or their "parent" branches.
    "###);
}

fn get_log_output(test_env: &TestEnvironment, workspace_root: &Path) -> String {
    test_env.jj_cmd_success(workspace_root, &["log", "-T", "commit_id \" \" branches"])
}

#[test]
fn test_git_colocated_unreachable_commits() {
    let test_env = TestEnvironment::default();
    let workspace_root = test_env.env_root().join("repo");
    let git_repo = git2::Repository::init(&workspace_root).unwrap();

    // Create an initial commit in Git
    let empty_tree_oid = git_repo.treebuilder(None).unwrap().write().unwrap();
    let tree1 = git_repo.find_tree(empty_tree_oid).unwrap();
    let signature = git2::Signature::new(
        "Someone",
        "someone@example.com",
        &git2::Time::new(1234567890, 60),
    )
    .unwrap();
    let oid1 = git_repo
        .commit(
            Some("refs/heads/master"),
            &signature,
            &signature,
            "initial",
            &tree1,
            &[],
        )
        .unwrap();
    insta::assert_snapshot!(
        git_repo.head().unwrap().peel_to_commit().unwrap().id().to_string(),
        @"2ee37513d2b5e549f7478c671a780053614bff19"
    );

    // Add a second commit in Git
    let tree2 = git_repo.find_tree(empty_tree_oid).unwrap();
    let signature = git2::Signature::new(
        "Someone",
        "someone@example.com",
        &git2::Time::new(1234567890, 62),
    )
    .unwrap();
    let oid2 = git_repo
        .commit(
            None,
            &signature,
            &signature,
            "next",
            &tree2,
            &[&git_repo.find_commit(oid1).unwrap()],
        )
        .unwrap();
    insta::assert_snapshot!(
        git_repo.head().unwrap().peel_to_commit().unwrap().id().to_string(),
        @"2ee37513d2b5e549f7478c671a780053614bff19"
    );

    // Import the repo while there is no path to the second commit
    test_env.jj_cmd_success(&workspace_root, &["init", "--git-repo", "."]);
    insta::assert_snapshot!(get_log_output(&test_env, &workspace_root), @r###"
    @ 66ae47cee4f8c28ee8d7e4f5d9401b03c07e22f2 
    o 2ee37513d2b5e549f7478c671a780053614bff19 master
    o 0000000000000000000000000000000000000000 
    "###);
    insta::assert_snapshot!(
        git_repo.head().unwrap().peel_to_commit().unwrap().id().to_string(),
        @"2ee37513d2b5e549f7478c671a780053614bff19"
    );

    // Check that trying to look up the second commit fails gracefully
    let stderr = test_env.jj_cmd_failure(&workspace_root, &["show", &oid2.to_string()]);
    insta::assert_snapshot!(stderr, @r###"
    Error: Revision "8e713ff77b54928dd4a82aaabeca44b1ae91722c" doesn't exist
    "###);
}