use miette::{
    DefaultReportPrinter, Diagnostic, DiagnosticReport, MietteError, MietteTheme,
    NarratableReportPrinter, SourceSpan,
};
use thiserror::Error;

fn fmt_report(diag: DiagnosticReport) -> String {
    let mut out = String::new();
    // Mostly for dev purposes.
    if std::env::var("STYLE").is_ok() {
        DefaultReportPrinter::new_themed(MietteTheme::unicode())
            .render_report(&mut out, diag.inner())
            .unwrap();
    } else {
        NarratableReportPrinter
            .render_report(&mut out, diag.inner())
            .unwrap();
    };
    out
}

#[test]
fn single_line_highlight() -> Result<(), MietteError> {
    #[derive(Debug, Diagnostic, Error)]
    #[error("oops!")]
    #[diagnostic(code(oops::my::bad), help("try doing it better next time?"))]
    struct MyBad {
        src: String,
        #[snippet(src, "This is the part that broke")]
        ctx: SourceSpan,
        #[highlight(ctx)]
        highlight: SourceSpan,
    }

    let src = "source\n  text\n    here".to_string();
    let len = src.len();
    let err = MyBad {
        src,
        ctx: ("bad_file.rs", 0, len).into(),
        highlight: ("this bit here", 9, 4).into(),
    };
    let out = fmt_report(err.into());
    println!("{}", out);
    let expected = r#"
oops!
    Diagnostic severity: error

Begin snippet for bad_file.rs starting at line 1, column 1

snippet line 1: source
snippet line 2:   text
    highlight starting at line 2, column 3: this bit here
snippet line 3:     here

diagnostic help: try doing it better next time?
diagnostic error code: oops::my::bad
"#
    .trim_start()
    .to_string();
    assert_eq!(expected, out);
    Ok(())
}

#[test]
fn single_line_highlight_no_label() -> Result<(), MietteError> {
    #[derive(Debug, Diagnostic, Error)]
    #[error("oops!")]
    #[diagnostic(code(oops::my::bad), help("try doing it better next time?"))]
    struct MyBad {
        src: String,
        #[snippet(src, "This is the part that broke")]
        ctx: SourceSpan,
        #[highlight(ctx)]
        highlight: SourceSpan,
    }

    let src = "source\n  text\n    here".to_string();
    let len = src.len();
    let err = MyBad {
        src,
        ctx: ("bad_file.rs", 0, len).into(),
        highlight: (9, 4).into(),
    };
    let out = fmt_report(err.into());
    println!("{}", out);
    let expected = r#"
oops!
    Diagnostic severity: error

Begin snippet for bad_file.rs starting at line 1, column 1

snippet line 1: source
snippet line 2:   text
    highlight starting at line 2, column 3
snippet line 3:     here

diagnostic help: try doing it better next time?
diagnostic error code: oops::my::bad
"#
    .trim_start()
    .to_string();
    assert_eq!(expected, out);
    Ok(())
}

#[test]
fn multiple_same_line_highlights() -> Result<(), MietteError> {
    #[derive(Debug, Diagnostic, Error)]
    #[error("oops!")]
    #[diagnostic(code(oops::my::bad), help("try doing it better next time?"))]
    struct MyBad {
        src: String,
        #[snippet(src, "This is the part that broke")]
        ctx: SourceSpan,
        #[highlight(ctx)]
        highlight1: SourceSpan,
        #[highlight(ctx)]
        highlight2: SourceSpan,
    }

    let src = "source\n  text text text text text\n    here".to_string();
    let len = src.len();
    let err = MyBad {
        src,
        ctx: ("bad_file.rs", 0, len).into(),
        highlight1: ("this bit here", 9, 4).into(),
        highlight2: ("also this bit", 14, 4).into(),
    };
    let out = fmt_report(err.into());
    println!("{}", out);
    let expected = r#"
oops!
    Diagnostic severity: error

Begin snippet for bad_file.rs starting at line 1, column 1

snippet line 1: source
snippet line 2:   text text text text text
    highlight starting at line 2, column 3: this bit here
    highlight starting at line 2, column 8: also this bit
snippet line 3:     here

diagnostic help: try doing it better next time?
diagnostic error code: oops::my::bad
"#
    .trim_start()
    .to_string();
    assert_eq!(expected, out);
    Ok(())
}

#[test]
fn multiline_highlight_adjacent() -> Result<(), MietteError> {
    #[derive(Debug, Diagnostic, Error)]
    #[error("oops!")]
    #[diagnostic(code(oops::my::bad), help("try doing it better next time?"))]
    struct MyBad {
        src: String,
        #[snippet(src, "This is the part that broke")]
        ctx: SourceSpan,
        #[highlight(ctx)]
        highlight: SourceSpan,
    }

    let src = "source\n  text\n    here".to_string();
    let len = src.len();
    let err = MyBad {
        src,
        ctx: ("bad_file.rs", 0, len).into(),
        highlight: ("these two lines", 9, 11).into(),
    };
    let out = fmt_report(err.into());
    println!("{}", out);
    let expected = r#"
oops!
    Diagnostic severity: error

Begin snippet for bad_file.rs starting at line 1, column 1

snippet line 1: source
snippet line 2:   text
    highlight starting at line 2, column 3: these two lines
snippet line 3:     here

diagnostic help: try doing it better next time?
diagnostic error code: oops::my::bad
"#
    .trim_start()
    .to_string();
    assert_eq!(expected, out);
    Ok(())
}

#[test]
fn multiline_highlight_flyby() -> Result<(), MietteError> {
    #[derive(Debug, Diagnostic, Error)]
    #[error("oops!")]
    #[diagnostic(code(oops::my::bad), help("try doing it better next time?"))]
    struct MyBad {
        src: String,
        #[snippet(src, "This is the part that broke")]
        ctx: SourceSpan,
        #[highlight(ctx)]
        highlight1: SourceSpan,
        #[highlight(ctx)]
        highlight2: SourceSpan,
    }

    let src = r#"line1
line2
line3
line4
line5
"#
    .to_string();
    let len = src.len();
    let err = MyBad {
        src,
        ctx: ("bad_file.rs", 0, len).into(),
        highlight1: ("block 1", 0, len).into(),
        highlight2: ("block 2", 10, 9).into(),
    };
    let out = fmt_report(err.into());
    println!("{}", out);
    let expected = r#"
oops!
    Diagnostic severity: error

Begin snippet for bad_file.rs starting at line 1, column 1

snippet line 1: line1
    highlight starting at line 1, column 1: block 1
snippet line 2: line2
    highlight starting at line 2, column 5: block 2
snippet line 3: line3
snippet line 4: line4
snippet line 6: line5

diagnostic help: try doing it better next time?
diagnostic error code: oops::my::bad
"#
    .trim_start()
    .to_string();
    assert_eq!(expected, out);
    Ok(())
}

#[test]
fn multiline_highlight_no_label() -> Result<(), MietteError> {
    #[derive(Debug, Diagnostic, Error)]
    #[error("oops!")]
    #[diagnostic(code(oops::my::bad), help("try doing it better next time?"))]
    struct MyBad {
        src: String,
        #[snippet(src, "This is the part that broke")]
        ctx: SourceSpan,
        #[highlight(ctx)]
        highlight1: SourceSpan,
        #[highlight(ctx)]
        highlight2: SourceSpan,
    }

    let src = r#"line1
line2
line3
line4
line5
"#
    .to_string();
    let len = src.len();
    let err = MyBad {
        src,
        ctx: ("bad_file.rs", 0, len).into(),
        highlight1: ("block 1", 0, len).into(),
        highlight2: (10, 9).into(),
    };
    let out = fmt_report(err.into());
    println!("{}", out);
    let expected = r#"
oops!
    Diagnostic severity: error

Begin snippet for bad_file.rs starting at line 1, column 1

snippet line 1: line1
    highlight starting at line 1, column 1: block 1
snippet line 2: line2
    highlight starting at line 2, column 5
snippet line 3: line3
snippet line 4: line4
snippet line 6: line5

diagnostic help: try doing it better next time?
diagnostic error code: oops::my::bad
"#
    .trim_start()
    .to_string();
    assert_eq!(expected, out);
    Ok(())
}

#[test]
fn multiple_multiline_highlights_adjacent() -> Result<(), MietteError> {
    #[derive(Debug, Diagnostic, Error)]
    #[error("oops!")]
    #[diagnostic(code(oops::my::bad), help("try doing it better next time?"))]
    struct MyBad {
        src: String,
        #[snippet(src, "This is the part that broke")]
        ctx: SourceSpan,
        #[highlight(ctx)]
        highlight1: SourceSpan,
        #[highlight(ctx)]
        highlight2: SourceSpan,
    }

    let src = "source\n  text\n    here\nmore here".to_string();
    let len = src.len();
    let err = MyBad {
        src,
        ctx: ("bad_file.rs", 0, len).into(),
        highlight1: ("this bit here", 0, 10).into(),
        highlight2: ("also this bit", 20, 6).into(),
    };
    let out = fmt_report(err.into());
    println!("{}", out);
    let expected = r#"
oops!
    Diagnostic severity: error

Begin snippet for bad_file.rs starting at line 1, column 1

snippet line 1: source
    highlight starting at line 1, column 1: this bit here
snippet line 2:   text
snippet line 3:     here
    highlight starting at line 3, column 7: also this bit
snippet line 4: more here

diagnostic help: try doing it better next time?
diagnostic error code: oops::my::bad
"#
    .trim_start()
    .to_string();
    assert_eq!(expected, out);
    Ok(())
}

#[test]
/// Lines are overlapping, but the offsets themselves aren't, so they _look_
/// disjunct if you only look at offsets.
fn multiple_multiline_highlights_overlapping_lines() -> Result<(), MietteError> {
    #[derive(Debug, Diagnostic, Error)]
    #[error("oops!")]
    #[diagnostic(code(oops::my::bad), help("try doing it better next time?"))]
    struct MyBad {
        src: String,
        #[snippet(src, "This is the part that broke")]
        ctx: SourceSpan,
        #[highlight(ctx)]
        highlight1: SourceSpan,
        #[highlight(ctx)]
        highlight2: SourceSpan,
    }

    let src = "source\n  text\n    here".to_string();
    let len = src.len();
    let err = MyBad {
        src,
        ctx: ("bad_file.rs", 0, len).into(),
        highlight1: ("this bit here", 0, 8).into(),
        highlight2: ("also this bit", 9, 10).into(),
    };
    let out = fmt_report(err.into());
    println!("{}", out);
    let expected = r#"
oops!
    Diagnostic severity: error

Begin snippet for bad_file.rs starting at line 1, column 1

snippet line 1: source
    highlight starting at line 1, column 1: this bit here
snippet line 2:   text
    highlight starting at line 2, column 3: also this bit
snippet line 3:     here

diagnostic help: try doing it better next time?
diagnostic error code: oops::my::bad
"#
    .trim_start()
    .to_string();
    assert_eq!(expected, out);
    Ok(())
}

#[test]
/// Offsets themselves are overlapping, regardless of lines.
#[ignore]
fn multiple_multiline_highlights_overlapping_offsets() -> Result<(), MietteError> {
    #[derive(Debug, Diagnostic, Error)]
    #[error("oops!")]
    #[diagnostic(code(oops::my::bad), help("try doing it better next time?"))]
    struct MyBad {
        src: String,
        #[snippet(src, "This is the part that broke")]
        ctx: SourceSpan,
        #[highlight(ctx)]
        highlight1: SourceSpan,
        #[highlight(ctx)]
        highlight2: SourceSpan,
    }

    let src = "source\n  text\n    here".to_string();
    let len = src.len();
    let err = MyBad {
        src,
        ctx: ("bad_file.rs", 0, len).into(),
        highlight1: ("this bit here", 0, 8).into(),
        highlight2: ("also this bit", 10, 10).into(),
    };
    let out = fmt_report(err.into());
    println!("{}", out);
    let expected = r#"
oops!
    Diagnostic severity: error

Begin snippet for bad_file.rs starting at line 1, column 1

snippet line 1: source
    highlight starting at line 1, column 1: this bit here
snippet line 2:   text
    highlight starting at line 2, column 4: also this bit
snippet line 3:     here

diagnostic help: try doing it better next time?
diagnostic error code: oops::my::bad
"#
    .trim_start()
    .to_string();
    assert_eq!(expected, out);
    Ok(())
}