use super::*;

fn test_sources(sides: usize) -> Vec<Source> {
    (0..sides * 2 - 1)
        .map(|index| Source {
            label: format!("source {index}"),
            base: index % 2 == 1,
            kind: FileKind::Text,
            bytes: b"historical full file; must never replace working text\n".to_vec(),
            tree_id: String::new(),
            term: index / 2,
            sides,
            bases: sides - 1,
            node: Node::Absent,
        })
        .collect()
}

fn snapshot(left: &str, base: &str, right: &str) -> String {
    format!(
        "<<<<<<< conflict\n+++++++ side 1\n{left}------- base\n{base}+++++++ side 2\n{right}>>>>>>> conflict ends\n"
    )
}

#[test]
fn current_working_projections_keep_partial_resolutions_and_multiple_regions() {
    let sources = test_sources(2);
    let raw = format!(
        "unsaved heading\nalready manually resolved\n{}auto-merged middle\n<<<<<<< conflict\n%%%%%%% Changes from base to side 1\n\\\\\\\\\\\\\\ continuation\n-old two\n+left two\n+++++++ side 2\nright two\n>>>>>>> conflict ends\nunsaved tail",
        snapshot("left one\n", "old one\n", "right one\n")
    );
    for (index, first, second) in [
        (0, "left one", "left two"),
        (1, "old one", "old two"),
        (2, "right one", "right two"),
    ] {
        assert_eq!(
            project(&raw, &sources[index]).unwrap(),
            format!(
                "unsaved heading\nalready manually resolved\n{first}\nauto-merged middle\n{second}\nunsaved tail"
            )
        );
    }
}

#[test]
fn alternatives_are_frozen_from_the_same_working_text_as_the_seed() {
    let sources = test_sources(2);
    let raw = format!(
        "unsaved heading\n{}auto-merged middle\n{}unsaved tail",
        snapshot("left-one\n", "old-one\n", "right-one\n"),
        snapshot("left-two\n", "old-two\n", "right-two\n")
    );
    let projection = Projection::new(&raw, &sources, 0).unwrap();
    let mut draft = projection.seed().to_owned();
    draft = draft.replace("unsaved heading", "later draft edit");
    draft.push_str("\nnew draft ending\n");
    assert_eq!(
        projection.alternative(2).unwrap(),
        "unsaved heading\nright-one\nauto-merged middle\nright-two\nunsaved tail"
    );
    assert_eq!(
        projection.alternative(1).unwrap(),
        "unsaved heading\nold-one\nauto-merged middle\nold-two\nunsaved tail"
    );
    assert_eq!(
        projection.seed(),
        "unsaved heading\nleft-one\nauto-merged middle\nleft-two\nunsaved tail"
    );
    assert_eq!(
        draft,
        "later draft edit\nleft-one\nauto-merged middle\nleft-two\nunsaved tail\nnew draft ending\n"
    );
}

#[test]
fn all_multiway_sides_and_bases_project_the_same_current_context() {
    let sources = test_sources(3);
    let raw = "unsaved α\n<<<<<<<<<<< conflict\n+++++++++++ side 1\none\n----------- base 1\nold one\n+++++++++++ side 2\ntwo\n----------- base 2\nold two\n+++++++++++ side 3\nthree\n>>>>>>>>>>> conflict ends\nunsaved ω";
    let projection = Projection::new(raw, &sources, 0).unwrap();
    for (index, choice) in ["one", "old one", "two", "old two", "three"]
        .into_iter()
        .enumerate()
    {
        let expected = format!("unsaved α\n{choice}\nunsaved ω");
        assert_eq!(project(raw, &sources[index]).unwrap(), expected);
        assert_eq!(projection.alternative(index).unwrap(), expected);
    }
    assert_eq!(
        Projection::new(raw, &sources, 4).unwrap().seed(),
        "unsaved α\nthree\nunsaved ω"
    );
}

#[test]
fn projections_preserve_mixed_eof_and_crlf_terms() {
    let sources = test_sources(2);
    for eol in ["\n", "\r\n"] {
        let choices = [
            format!("left{eol}"),
            "old".to_owned(),
            format!("right{eol}{eol}"),
        ];
        // jj appends one separator EOL to *each* term when any lacks an EOL,
        // and omits the EOL on the final marker. Existing term EOLs remain.
        let raw = format!(
            "heading{eol}<<<<<<< conflict{eol}+++++++ side 1{eol}{}{eol}------- base{eol}{}{eol}+++++++ side 2{eol}{}{eol}>>>>>>> conflict ends",
            choices[0], choices[1], choices[2]
        );
        let projection = Projection::new(&raw, &sources, 0).unwrap();
        for (index, choice) in choices.iter().enumerate() {
            assert_eq!(
                project(&raw, &sources[index]).unwrap(),
                format!("heading{eol}{choice}")
            );
            assert_eq!(
                projection.alternative(index).unwrap(),
                format!("heading{eol}{choice}")
            );
        }
    }
}

#[test]
fn empty_choices_markerfree_text_and_invalid_choices_are_handled() {
    let mut sources = test_sources(2);
    sources[1].kind = FileKind::Deleted;
    let raw = format!("before\n{}after\n", snapshot("", "", "new\n"));
    let projection = Projection::new(&raw, &sources, 0).unwrap();
    assert_eq!(projection.seed(), "before\nafter\n");
    assert_eq!(projection.alternative(1).unwrap(), "before\nafter\n");
    assert_eq!(projection.alternative(2).unwrap(), "before\nnew\nafter\n");
    let resolved = Projection::new("manually resolved, no final EOL", &sources, 0).unwrap();
    assert_eq!(
        resolved.alternative(2).unwrap(),
        "manually resolved, no final EOL"
    );
    assert!(resolved.alternative(sources.len()).is_err());
    assert!(Projection::new(&raw, &sources, sources.len()).is_err());
    assert!(Projection::new(&raw, &test_sources(3), 0).is_err());
    sources[0].kind = FileKind::Binary;
    assert!(project(&raw, &sources[0]).is_err());
}