use oxc_compat::EngineTargets;
use rustc_hash::FxHashSet;

pub use oxc_ecmascript::side_effects::PropertyReadSideEffects;

#[derive(Debug, Clone)]
pub struct CompressOptions {
    /// Engine targets for feature detection.
    ///
    /// Used to determine which ES features are supported by the target engines
    /// and whether transformations can be applied.
    ///
    /// Default: empty (supports all features)
    pub target: EngineTargets,

    /// Remove `debugger;` statements.
    ///
    /// Default `true`
    pub drop_debugger: bool,

    /// Remove `console.*` statements.
    ///
    /// Default `false`
    pub drop_console: bool,

    /// Join consecutive var, let and const statements.
    ///
    /// Default `true`
    pub join_vars: bool,

    /// Join consecutive simple statements using the comma operator.
    ///
    /// `a; b` -> `a, b`
    ///
    /// Default `true`
    pub sequences: bool,

    /// Drop unreferenced functions and variables.
    pub unused: CompressOptionsUnused,

    /// Keep function / class names.
    pub keep_names: CompressOptionsKeepNames,

    /// Treeshake Options .
    /// <https://rollupjs.org/configuration-options/#treeshake>
    pub treeshake: TreeShakeOptions,

    /// Set of label names to drop from the code.
    ///
    /// Labeled statements matching these names will be removed during minification.
    ///
    /// Default: empty (no labels dropped)
    pub drop_labels: FxHashSet<String>,

    /// Limit the maximum number of iterations for debugging purpose.
    pub max_iterations: Option<u8>,
}

impl Default for CompressOptions {
    fn default() -> Self {
        Self::smallest()
    }
}

impl CompressOptions {
    pub fn smallest() -> Self {
        Self {
            target: EngineTargets::default(),
            keep_names: CompressOptionsKeepNames::all_false(),
            drop_debugger: true,
            drop_console: false,
            join_vars: true,
            sequences: true,
            unused: CompressOptionsUnused::Remove,
            treeshake: TreeShakeOptions::default(),
            drop_labels: FxHashSet::default(),
            max_iterations: None,
        }
    }

    pub fn safest() -> Self {
        Self {
            target: EngineTargets::default(),
            keep_names: CompressOptionsKeepNames::all_true(),
            drop_debugger: false,
            drop_console: false,
            join_vars: true,
            sequences: true,
            unused: CompressOptionsUnused::Keep,
            treeshake: TreeShakeOptions::default(),
            drop_labels: FxHashSet::default(),
            max_iterations: None,
        }
    }

    pub fn dce() -> Self {
        Self {
            target: EngineTargets::default(),
            keep_names: CompressOptionsKeepNames::all_true(),
            drop_debugger: false,
            drop_console: false,
            join_vars: false,
            sequences: false,
            unused: CompressOptionsUnused::Remove,
            treeshake: TreeShakeOptions::default(),
            drop_labels: FxHashSet::default(),
            max_iterations: None,
        }
    }
}

#[derive(Debug, Clone, Copy, Eq, PartialEq, Default)]
pub enum CompressOptionsUnused {
    #[default]
    Remove,
    KeepAssign,
    Keep,
}

#[derive(Debug, Clone, Copy, Default)]
pub struct CompressOptionsKeepNames {
    /// Keep function names so that `Function.prototype.name` is preserved.
    ///
    /// This does not guarantee that the `undefined` name is preserved.
    ///
    /// Default `false`
    pub function: bool,

    /// Keep class names so that `Class.prototype.name` is preserved.
    ///
    /// This does not guarantee that the `undefined` name is preserved.
    ///
    /// Default `false`
    pub class: bool,
}

impl CompressOptionsKeepNames {
    pub fn all_false() -> Self {
        Self { function: false, class: false }
    }

    pub fn all_true() -> Self {
        Self { function: true, class: true }
    }

    pub fn function_only() -> Self {
        Self { function: true, class: false }
    }

    pub fn class_only() -> Self {
        Self { function: false, class: true }
    }
}

#[derive(Debug, Clone)]
pub struct TreeShakeOptions {
    /// Whether to respect the pure annotations.
    ///
    /// Pure annotations are the comments that marks that a expression is pure.
    /// For example, `/* @__PURE__ */`, `/* #__NO_SIDE_EFFECTS__ */`.
    ///
    /// <https://rollupjs.org/configuration-options/#treeshake-annotations>
    ///
    /// Default `true`
    pub annotations: bool,

    /// Whether to treat this function call as pure.
    ///
    /// This function is called for normal function calls, new calls, and
    /// tagged template calls (`foo()`, `new Foo()`, ``foo`b` ``).
    ///
    /// <https://rollupjs.org/configuration-options/#treeshake-manualpurefunctions>
    pub manual_pure_functions: Vec<String>,

    /// Whether property read accesses have side effects.
    ///
    /// <https://rollupjs.org/configuration-options/#treeshake-propertyreadsideeffects>
    ///
    /// Default [PropertyReadSideEffects::All]
    pub property_read_side_effects: PropertyReadSideEffects,

    /// Whether property write accesses (assignments to member expressions) have side effects.
    ///
    /// When `false`, assignments like `obj.prop = value` are considered side-effect-free
    /// (assuming the object and value expressions themselves are side-effect-free).
    /// This enables dropping property assignments to unused local variables,
    /// e.g. `function A() {} A.from = () => {}` can be eliminated entirely.
    ///
    /// Requires assuming that `Object.prototype` / `Function.prototype` properties
    /// are not setters with side effects.
    ///
    /// <https://rolldown.rs/reference/InputOptions.treeshake#propertywritesideeffects>
    ///
    /// Default `true`
    pub property_write_side_effects: bool,

    /// Whether accessing a global variable has side effects.
    ///
    /// Accessing a non-existing global variable will throw an error.
    /// Global variable may be a getter that has side effects.
    ///
    /// <https://rollupjs.org/configuration-options/#treeshake-unknownglobalsideeffects>
    ///
    /// Default `true`
    pub unknown_global_side_effects: bool,

    /// Whether invalid import statements have side effects.
    ///
    /// Accessing a non-existing import name will throw an error.
    /// Also import statements that cannot be resolved will throw an error.
    ///
    /// Default `false`
    pub invalid_import_side_effects: bool,
}

impl Default for TreeShakeOptions {
    fn default() -> Self {
        Self {
            annotations: true,
            manual_pure_functions: vec![],
            property_read_side_effects: PropertyReadSideEffects::default(),
            property_write_side_effects: true,
            unknown_global_side_effects: true,
            invalid_import_side_effects: false,
        }
    }
}
