mago-reporting 0.26.1

use std::cmp::Ordering;
use std::ops::Range;

use codespan_reporting::diagnostic::Diagnostic;
use codespan_reporting::diagnostic::Label;
use codespan_reporting::diagnostic::LabelStyle;
use codespan_reporting::diagnostic::Severity;
use codespan_reporting::files::Error;
use codespan_reporting::files::Files;
use codespan_reporting::term;
use codespan_reporting::term::Config;
use codespan_reporting::term::DisplayStyle;
use termcolor::WriteColor;

use mago_interner::ThreadedInterner;
use mago_source::SourceIdentifier;
use mago_source::SourceManager;
use mago_source::error::SourceError;

use crate::Annotation;
use crate::AnnotationKind;
use crate::Issue;
use crate::IssueCollection;
use crate::Level;
use crate::error::ReportingError;

pub fn rich_format(
    writer: &mut dyn WriteColor,
    sources: &SourceManager,
    interner: &ThreadedInterner,
    issues: IssueCollection,
) -> Result<Option<Level>, ReportingError> {
    codespan_format_with_config(
        writer,
        sources,
        interner,
        issues,
        Config { display_style: DisplayStyle::Rich, ..Default::default() },
    )
}

pub fn medium_format(
    writer: &mut dyn WriteColor,
    sources: &SourceManager,
    interner: &ThreadedInterner,
    issues: IssueCollection,
) -> Result<Option<Level>, ReportingError> {
    codespan_format_with_config(
        writer,
        sources,
        interner,
        issues,
        Config { display_style: DisplayStyle::Medium, ..Default::default() },
    )
}

pub fn short_format(
    writer: &mut dyn WriteColor,
    sources: &SourceManager,
    interner: &ThreadedInterner,
    issues: IssueCollection,
) -> Result<Option<Level>, ReportingError> {
    codespan_format_with_config(
        writer,
        sources,
        interner,
        issues,
        Config { display_style: DisplayStyle::Short, ..Default::default() },
    )
}

fn codespan_format_with_config(
    writer: &mut dyn WriteColor,
    sources: &SourceManager,
    interner: &ThreadedInterner,
    issues: IssueCollection,
    config: Config,
) -> Result<Option<Level>, ReportingError> {
    let files = SourceManagerFile(sources, interner);

    let highest_level = issues.get_highest_level();
    let mut errors = 0;
    let mut warnings = 0;
    let mut notes = 0;
    let mut help = 0;
    let mut suggestions = 0;

    for issue in issues {
        match &issue.level {
            Level::Note => {
                notes += 1;
            }
            Level::Help => {
                help += 1;
            }
            Level::Warning => {
                warnings += 1;
            }
            Level::Error => {
                errors += 1;
            }
        }

        if !issue.suggestions.is_empty() {
            suggestions += 1;
        }

        let diagnostic: Diagnostic<SourceIdentifier> = issue.into();

        term::emit(writer, &config, &files, &diagnostic)?;
    }

    if let Some(highest_level) = highest_level {
        let total_issues = errors + warnings + notes + help;
        let mut message_notes = vec![];
        if errors > 0 {
            message_notes.push(format!("{errors} error(s)"));
        }

        if warnings > 0 {
            message_notes.push(format!("{warnings} warning(s)"));
        }

        if notes > 0 {
            message_notes.push(format!("{notes} note(s)"));
        }

        if help > 0 {
            message_notes.push(format!("{help} help message(s)"));
        }

        let mut diagnostic: Diagnostic<SourceIdentifier> = Diagnostic::new(highest_level.into()).with_message(format!(
            "found {} issues: {}",
            total_issues,
            message_notes.join(", ")
        ));

        if suggestions > 0 {
            diagnostic = diagnostic.with_notes(vec![format!("{} issues contain auto-fix suggestions", suggestions)]);
        }

        term::emit(writer, &config, &files, &diagnostic)?;
    }

    Ok(highest_level)
}

struct SourceManagerFile<'a>(&'a SourceManager, &'a ThreadedInterner);

impl<'a> Files<'a> for SourceManagerFile<'_> {
    type FileId = SourceIdentifier;
    type Name = &'a str;
    type Source = &'a str;

    fn name(&'a self, file_id: SourceIdentifier) -> Result<&'a str, Error> {
        self.0.load(&file_id).map(|source| self.1.lookup(&source.identifier.value())).map_err(|e| match e {
            SourceError::UnavailableSource(_) => Error::FileMissing,
            SourceError::IOError(error) => Error::Io(error),
        })
    }

    fn source(&'a self, file_id: SourceIdentifier) -> Result<&'a str, Error> {
        self.0.load(&file_id).map(|source| self.1.lookup(&source.content)).map_err(|e| match e {
            SourceError::UnavailableSource(_) => Error::FileMissing,
            SourceError::IOError(error) => Error::Io(error),
        })
    }

    fn line_index(&self, file_id: SourceIdentifier, byte_index: usize) -> Result<usize, Error> {
        let source = self.0.load(&file_id).map_err(|e| match e {
            SourceError::UnavailableSource(_) => Error::FileMissing,
            SourceError::IOError(error) => Error::Io(error),
        })?;

        Ok(source.line_number(byte_index))
    }

    fn line_range(&self, file_id: SourceIdentifier, line_index: usize) -> Result<Range<usize>, Error> {
        let source = self.0.load(&file_id).map_err(|e| match e {
            SourceError::UnavailableSource(_) => Error::FileMissing,
            SourceError::IOError(error) => Error::Io(error),
        })?;

        codespan_line_range(&source.lines, source.size, line_index)
    }
}

fn codespan_line_start(lines: &[usize], size: usize, line_index: usize) -> Result<usize, Error> {
    match line_index.cmp(&lines.len()) {
        Ordering::Less => Ok(lines.get(line_index).cloned().expect("failed despite previous check")),
        Ordering::Equal => Ok(size),
        Ordering::Greater => Err(Error::LineTooLarge { given: line_index, max: lines.len() - 1 }),
    }
}

fn codespan_line_range(lines: &[usize], size: usize, line_index: usize) -> Result<Range<usize>, Error> {
    let line_start = codespan_line_start(lines, size, line_index)?;
    let next_line_start = codespan_line_start(lines, size, line_index + 1)?;

    Ok(line_start..next_line_start)
}

impl From<AnnotationKind> for LabelStyle {
    fn from(kind: AnnotationKind) -> LabelStyle {
        match kind {
            AnnotationKind::Primary => LabelStyle::Primary,
            AnnotationKind::Secondary => LabelStyle::Secondary,
        }
    }
}

impl From<Annotation> for Label<SourceIdentifier> {
    fn from(annotation: Annotation) -> Label<SourceIdentifier> {
        let mut label = Label::new(annotation.kind.into(), annotation.span.start.source, annotation.span);

        if let Some(message) = annotation.message {
            label.message = message;
        }

        label
    }
}

impl From<Level> for Severity {
    fn from(level: Level) -> Severity {
        match level {
            Level::Note => Severity::Note,
            Level::Help => Severity::Help,
            Level::Warning => Severity::Warning,
            Level::Error => Severity::Error,
        }
    }
}

impl From<Issue> for Diagnostic<SourceIdentifier> {
    fn from(issue: Issue) -> Diagnostic<SourceIdentifier> {
        let mut diagnostic = Diagnostic::new(issue.level.into()).with_message(issue.message);

        if let Some(code) = issue.code {
            diagnostic.code = Some(code);
        }

        for annotation in issue.annotations {
            diagnostic.labels.push(annotation.into());
        }

        for note in issue.notes {
            diagnostic.notes.push(note);
        }

        if let Some(help) = issue.help {
            diagnostic.notes.push(format!("Help: {help}"));
        }

        if let Some(link) = issue.link {
            diagnostic.notes.push(format!("See: {link}"));
        }

        diagnostic
    }
}