use crate::common::*;

#[derive(Debug, PartialEq)]
pub(crate) struct CompilationError<'src> {
  pub(crate) token: Token<'src>,
  pub(crate) kind:  CompilationErrorKind<'src>,
}

impl Error for CompilationError<'_> {}

impl Display for CompilationError<'_> {
  fn fmt(&self, f: &mut Formatter) -> Result<(), fmt::Error> {
    use CompilationErrorKind::*;
    let message = Color::fmt(f).message();

    write!(f, "{}", message.prefix())?;

    match self.kind {
      AliasShadowsRecipe { alias, recipe_line } => {
        writeln!(
          f,
          "Alias `{}` defined on line {} shadows recipe `{}` defined on line {}",
          alias,
          self.token.line.ordinal(),
          alias,
          recipe_line.ordinal(),
        )?;
      },
      CircularRecipeDependency { recipe, ref circle } =>
        if circle.len() == 2 {
          writeln!(f, "Recipe `{}` depends on itself", recipe)?;
        } else {
          writeln!(
            f,
            "Recipe `{}` has circular dependency `{}`",
            recipe,
            circle.join(" -> ")
          )?;
        },
      CircularVariableDependency {
        variable,
        ref circle,
      } =>
        if circle.len() == 2 {
          writeln!(f, "Variable `{}` is defined in terms of itself", variable)?;
        } else {
          writeln!(
            f,
            "Variable `{}` depends on its own value: `{}`",
            variable,
            circle.join(" -> ")
          )?;
        },

      InvalidEscapeSequence { character } => {
        let representation = match character {
          '`' => r"\`".to_string(),
          '\\' => r"\".to_string(),
          '\'' => r"'".to_string(),
          '"' => r#"""#.to_string(),
          _ => character.escape_default().collect(),
        };
        writeln!(f, "`\\{}` is not a valid escape sequence", representation)?;
      },
      DuplicateParameter { recipe, parameter } => {
        writeln!(
          f,
          "Recipe `{}` has duplicate parameter `{}`",
          recipe, parameter
        )?;
      },
      DuplicateVariable { variable } => {
        writeln!(f, "Variable `{}` has multiple definitions", variable)?;
      },
      UnexpectedToken {
        ref expected,
        found,
      } => {
        writeln!(f, "Expected {}, but found {}", List::or(expected), found)?;
      },
      DuplicateAlias { alias, first } => {
        writeln!(
          f,
          "Alias `{}` first defined on line {} is redefined on line {}",
          alias,
          first.ordinal(),
          self.token.line.ordinal(),
        )?;
      },
      DuplicateRecipe { recipe, first } => {
        writeln!(
          f,
          "Recipe `{}` first defined on line {} is redefined on line {}",
          recipe,
          first.ordinal(),
          self.token.line.ordinal()
        )?;
      },
      DuplicateSet { setting, first } => {
        writeln!(
          f,
          "Setting `{}` first set on line {} is redefined on line {}",
          setting,
          first.ordinal(),
          self.token.line.ordinal(),
        )?;
      },
      DependencyArgumentCountMismatch {
        dependency,
        found,
        min,
        max,
      } => {
        write!(
          f,
          "Dependency `{}` got {} {} but takes ",
          dependency,
          found,
          Count("argument", found),
        )?;

        if min == max {
          let expected = min;
          writeln!(f, "{} {}", expected, Count("argument", expected))?;
        } else if found < min {
          writeln!(f, "at least {} {}", min, Count("argument", min))?;
        } else {
          writeln!(f, "at most {} {}", max, Count("argument", max))?;
        }
      },
      ExpectedKeyword { expected, found } => writeln!(
        f,
        "Expected keyword `{}` but found identifier `{}`",
        expected, found
      )?,
      ParameterShadowsVariable { parameter } => {
        writeln!(
          f,
          "Parameter `{}` shadows variable of the same name",
          parameter
        )?;
      },
      RequiredParameterFollowsDefaultParameter { parameter } => {
        writeln!(
          f,
          "Non-default parameter `{}` follows default parameter",
          parameter
        )?;
      },
      ParameterFollowsVariadicParameter { parameter } => {
        writeln!(f, "Parameter `{}` follows variadic parameter", parameter)?;
      },
      MixedLeadingWhitespace { whitespace } => {
        writeln!(
          f,
          "Found a mix of tabs and spaces in leading whitespace: `{}`\nLeading whitespace may \
           consist of tabs or spaces, but not both",
          ShowWhitespace(whitespace)
        )?;
      },
      ExtraLeadingWhitespace => {
        writeln!(f, "Recipe line has extra leading whitespace")?;
      },
      FunctionArgumentCountMismatch {
        function,
        found,
        expected,
      } => {
        writeln!(
          f,
          "Function `{}` called with {} {} but takes {}",
          function,
          found,
          Count("argument", found),
          expected
        )?;
      },
      InconsistentLeadingWhitespace { expected, found } => {
        writeln!(
          f,
          "Recipe line has inconsistent leading whitespace. Recipe started with `{}` but found \
           line with `{}`",
          ShowWhitespace(expected),
          ShowWhitespace(found)
        )?;
      },
      UnknownAliasTarget { alias, target } => {
        writeln!(f, "Alias `{}` has an unknown target `{}`", alias, target)?;
      },
      UnknownDependency { recipe, unknown } => {
        writeln!(
          f,
          "Recipe `{}` has unknown dependency `{}`",
          recipe, unknown
        )?;
      },
      UndefinedVariable { variable } => {
        writeln!(f, "Variable `{}` not defined", variable)?;
      },
      UnknownFunction { function } => {
        writeln!(f, "Call to unknown function `{}`", function)?;
      },
      UnknownSetting { setting } => {
        writeln!(f, "Unknown setting `{}`", setting)?;
      },
      UnexpectedCharacter { expected } => {
        writeln!(f, "Expected character `{}`", expected)?;
      },
      UnknownStartOfToken => {
        writeln!(f, "Unknown start of token:")?;
      },
      MismatchedClosingDelimiter {
        open,
        open_line,
        close,
      } => {
        writeln!(
          f,
          "Mismatched closing delimiter `{}`. (Did you mean to close the `{}` on line {}?)",
          close.close(),
          open.open(),
          open_line.ordinal(),
        )?;
      },
      UnexpectedClosingDelimiter { close } => {
        writeln!(f, "Unexpected closing delimiter `{}`", close.close())?;
      },
      UnpairedCarriageReturn => {
        writeln!(f, "Unpaired carriage return")?;
      },
      UnterminatedInterpolation => {
        writeln!(f, "Unterminated interpolation")?;
      },
      UnterminatedString => {
        writeln!(f, "Unterminated string")?;
      },
      UnterminatedBacktick => {
        writeln!(f, "Unterminated backtick")?;
      },
      Internal { ref message } => {
        writeln!(
          f,
          "Internal error, this may indicate a bug in just: {}\n\
           consider filing an issue: https://github.com/casey/just/issues/new",
          message
        )?;
      },
    }

    write!(f, "{}", message.suffix())?;

    self.token.write_context(f, Color::fmt(f).error())
  }
}