//! Dependency analysis.

//!

//! Dependencies in CSS can be analyzed using the `analyze_dependencies` option

//! when printing a style sheet. These include other style sheets referenved via

//! the `@import` rule, as well as `url()` references. See [PrinterOptions](PrinterOptions).

//!

//! When dependency analysis is enabled, `@import` rules are removed, and `url()`

//! dependencies are replaced with hashed placeholders that can be substituted with

//! the final urls later (e.g. after bundling and content hashing).

use crate::css_modules::hash;

use crate::printer::PrinterOptions;

use crate::rules::import::ImportRule;

use crate::traits::ToCss;

use crate::values::url::Url;

#[cfg(feature = "visitor")]

use crate::visitor::Visit;

use cssparser::SourceLocation;

#[cfg(any(feature = "serde", feature = "nodejs"))]

use serde::Serialize;

/// Options for `analyze_dependencies` in `PrinterOptions`.

#[derive(Default)]

pub struct DependencyOptions {

  /// Whether to remove `@import` rules.

  pub remove_imports: bool,

}

/// A dependency.

#[derive(Debug)]

#[cfg_attr(any(feature = "serde", feature = "nodejs"), derive(Serialize))]

#[cfg_attr(

  any(feature = "serde", feature = "nodejs"),

  serde(tag = "type", rename_all = "lowercase")

)]

pub enum Dependency {

  /// An `@import` dependency.

  Import(ImportDependency),

  /// A `url()` dependency.

  Url(UrlDependency),

}

/// An `@import` dependency.

#[derive(Debug)]

#[cfg_attr(any(feature = "serde", feature = "nodejs"), derive(Serialize))]

pub struct ImportDependency {

  /// The url to import.

  pub url: String,

  /// The placeholder that the URL was replaced with.

  pub placeholder: String,

  /// An optional `supports()` condition.

  pub supports: Option<String>,

  /// A media query.

  pub media: Option<String>,

  /// The location of the dependency in the source file.

  pub loc: SourceRange,

}

impl ImportDependency {

  /// Creates a new dependency from an `@import` rule.

  pub fn new(rule: &ImportRule, filename: &str) -> ImportDependency {

    let supports = if let Some(supports) = &rule.supports {

      let s = supports.to_css_string(PrinterOptions::default()).unwrap();

      Some(s)

    } else {

      None

    };

    let media = if !rule.media.media_queries.is_empty() {

      let s = rule.media.to_css_string(PrinterOptions::default()).unwrap();

      Some(s)

    } else {

      None

    };

    let placeholder = hash(&format!("{}_{}", filename, rule.url), false);

    ImportDependency {

      url: rule.url.as_ref().to_owned(),

      placeholder,

      supports,

      media,

      loc: SourceRange::new(

        filename,

        Location {

          line: rule.loc.line + 1,

          column: rule.loc.column,

        },

        8,

        rule.url.len() + 2,

      ), // TODO: what about @import url(...)?

    }

  }

}

/// A `url()` dependency.

#[derive(Debug)]

#[cfg_attr(any(feature = "serde", feature = "nodejs"), derive(Serialize))]

pub struct UrlDependency {

  /// The url of the dependency.

  pub url: String,

  /// The placeholder that the URL was replaced with.

  pub placeholder: String,

  /// The location of the dependency in the source file.

  pub loc: SourceRange,

}

impl UrlDependency {

  /// Creates a new url dependency.

  pub fn new(url: &Url, filename: &str) -> UrlDependency {

    let placeholder = hash(&format!("{}_{}", filename, url.url), false);

    UrlDependency {

      url: url.url.to_string(),

      placeholder,

      loc: SourceRange::new(filename, url.loc, 4, url.url.len()),

    }

  }

}

/// Represents the range of source code where a dependency was found.

#[derive(Debug)]

#[cfg_attr(any(feature = "serde", feature = "nodejs"), derive(Serialize))]

#[cfg_attr(any(feature = "serde", feature = "nodejs"), serde(rename_all = "camelCase"))]

pub struct SourceRange {

  /// The filename in which the dependency was found.

  pub file_path: String,

  /// The starting line and column position of the dependency.

  pub start: Location,

  /// The ending line and column position of the dependency.

  pub end: Location,

}

/// A line and column position within a source file.

#[derive(Debug, Clone, Copy, PartialEq)]

#[cfg_attr(feature = "visitor", derive(Visit))]

Unexecuted instantiation: <lightningcss::dependencies::Location as lightningcss::visitor::Visit<lightningcss::parser::DefaultAtRule, fallow_extract::css_metrics::ValueCollector>>::visit_children

Unexecuted instantiation: <lightningcss::dependencies::Location as lightningcss::visitor::Visit<lightningcss::parser::DefaultAtRule, fallow_extract::css_metrics::FirstRgbColorCollector>>::visit_children

Unexecuted instantiation: <lightningcss::dependencies::Location as lightningcss::visitor::Visit<_, _>>::visit_children

#[cfg_attr(any(feature = "serde", feature = "nodejs"), derive(serde::Serialize))]

#[cfg_attr(any(feature = "serde"), derive(serde::Deserialize))]

#[cfg_attr(feature = "jsonschema", derive(schemars::JsonSchema))]

#[cfg_attr(feature = "into_owned", derive(static_self::IntoOwned))]

pub struct Location {

  /// The line number, starting from 1.

  pub line: u32,

  /// The column number, starting from 1.

  pub column: u32,

}

impl From<SourceLocation> for Location {

  fn from(loc: SourceLocation) -> Location {

    Location {

      line: loc.line + 1,

      column: loc.column,

    }

  }

}

impl SourceRange {

  fn new(filename: &str, loc: Location, offset: u32, len: usize) -> SourceRange {

    SourceRange {

      file_path: filename.into(),

      start: Location {

        line: loc.line,

        column: loc.column + offset,

      },

      end: Location {

        line: loc.line,

        column: loc.column + offset + (len as u32) - 1,

      },

    }

  }

}