/* LICENSE BEGIN
    This file is part of the SixtyFPS Project -- https://sixtyfps.io
    Copyright (c) 2020 Olivier Goffart <olivier.goffart@sixtyfps.io>
    Copyright (c) 2020 Simon Hausmann <simon.hausmann@sixtyfps.io>

    SPDX-License-Identifier: GPL-3.0-only
    This file is also available under commercial licensing terms.
    Please contact info@sixtyfps.io for more information.
LICENSE END */
/*!
# SixtyFPS interpreter library

**NOTE:** This library is an internal crate for the SixtyFPS project.
This crate should not be used directly by application using SixtyFPS.
You should use the `sixtyfps` crate instead
*/

mod dynamic_component;
mod dynamic_type;
mod eval;
mod value_model;

pub use eval::{ModelPtr, Value};

use dynamic_component::InstanceRef;
pub use sixtyfps_compilerlib::CompilerConfiguration;
use sixtyfps_corelib::component::{ComponentRef, ComponentRefPin};
use std::{collections::HashMap, pin::Pin, rc::Rc};

impl<'id> dynamic_component::ComponentDescription<'id> {
    /// The name of this Component as written in the .60 file
    pub fn id(&self) -> &str {
        self.original.id.as_str()
    }

    /// List of publicly declared properties or signal
    pub fn properties(&self) -> HashMap<String, sixtyfps_compilerlib::typeregister::Type> {
        self.original
            .root_element
            .borrow()
            .property_declarations
            .iter()
            .map(|(s, v)| (s.clone(), v.property_type.clone()))
            .collect()
    }

    /// Instantiate a runtime component from this ComponentDescription
    pub fn create(
        self: Rc<Self>,
        #[cfg(target_arch = "wasm32")] canvas_id: String,
    ) -> dynamic_component::ComponentBox<'id> {
        dynamic_component::instantiate(
            self,
            None,
            #[cfg(target_arch = "wasm32")]
            canvas_id,
        )
    }

    /// Set a value to property.
    ///
    /// Returns an error if the component is not an instance corresponding to this ComponentDescription,
    /// or if the property with this name does not exist in this component
    pub fn set_property(
        &self,
        component: ComponentRefPin,
        name: &str,
        value: Value,
    ) -> Result<(), ()> {
        if !core::ptr::eq((&self.ct) as *const _, component.get_vtable() as *const _) {
            return Err(());
        }
        generativity::make_guard!(guard);
        let c = unsafe { InstanceRef::from_pin_ref(component, guard) };
        if let Some(alias) = self
            .original
            .root_element
            .borrow()
            .property_declarations
            .get(name)
            .and_then(|d| d.is_alias.as_ref())
        {
            eval::store_property(c, &alias.element.upgrade().unwrap(), &alias.name, value)
        } else {
            eval::store_property(c, &self.original.root_element, name, value)
        }
    }

    /// Set a binding to a property
    ///
    /// Returns an error if the component is not an instance corresponding to this ComponentDescription,
    /// or if the property with this name does not exist in this component
    pub fn set_binding(
        &self,
        component: ComponentRef,
        name: &str,
        binding: Box<dyn Fn() -> Value>,
    ) -> Result<(), ()> {
        if !core::ptr::eq((&self.ct) as *const _, component.get_vtable() as *const _) {
            return Err(());
        }
        let x = self.custom_properties.get(name).ok_or(())?;
        unsafe {
            x.prop
                .set_binding(Pin::new_unchecked(&*component.as_ptr().add(x.offset)), binding, None)
                .unwrap()
        };
        Ok(())
    }

    /// Return the value of a property
    ///
    /// Returns an error if the component is not an instance corresponding to this ComponentDescription,
    /// or if a signal with this name does not exist in this component
    pub fn get_property(&self, component: ComponentRefPin, name: &str) -> Result<Value, ()> {
        if !core::ptr::eq((&self.ct) as *const _, component.get_vtable() as *const _) {
            return Err(());
        }
        generativity::make_guard!(guard);
        // Safety: we just verified that the component has the right vtable
        let c = unsafe { InstanceRef::from_pin_ref(component, guard) };
        if let Some(alias) = self
            .original
            .root_element
            .borrow()
            .property_declarations
            .get(name)
            .and_then(|d| d.is_alias.as_ref())
        {
            eval::load_property(c, &alias.element.upgrade().unwrap(), &alias.name)
        } else {
            eval::load_property(c, &self.original.root_element, name)
        }
    }

    /// Sets an handler for a signal
    ///
    /// Returns an error if the component is not an instance corresponding to this ComponentDescription,
    /// or if the property with this name does not exist in this component
    pub fn set_signal_handler(
        &self,
        component: Pin<ComponentRef>,
        name: &str,
        handler: Box<dyn Fn(&[Value])>,
    ) -> Result<(), ()> {
        if !core::ptr::eq((&self.ct) as *const _, component.get_vtable() as *const _) {
            return Err(());
        }
        let x = self.custom_signals.get(name).ok_or(())?;
        let sig = x.apply(unsafe { &*(component.as_ptr() as *const dynamic_type::Instance) });
        sig.set_handler(handler);
        Ok(())
    }

    /// Emits the specified signal
    ///
    /// Returns an error if the component is not an instance corresponding to this ComponentDescription,
    /// or if the signal with this name does not exist in this component
    pub fn emit_signal(
        &self,
        component: ComponentRefPin,
        name: &str,
        args: &[Value],
    ) -> Result<(), ()> {
        if !core::ptr::eq((&self.ct) as *const _, component.get_vtable() as *const _) {
            return Err(());
        }
        let x = self.custom_signals.get(name).ok_or(())?;
        let sig = x.apply(unsafe { &*(component.as_ptr() as *const dynamic_type::Instance) });
        sig.emit(args);
        Ok(())
    }
}

pub type ComponentDescription = dynamic_component::ComponentDescription<'static>;
pub type ComponentBox = dynamic_component::ComponentBox<'static>;
pub fn load(
    source: String,
    path: &std::path::Path,
    mut compiler_config: CompilerConfiguration,
) -> (Result<Rc<ComponentDescription>, ()>, sixtyfps_compilerlib::diagnostics::BuildDiagnostics) {
    if compiler_config.style.is_none() && std::env::var("SIXTYFPS_STYLE").is_err() {
        // Defaults to native if it exists:
        compiler_config.style = Some(if sixtyfps_rendering_backend_default::HAS_NATIVE_STYLE {
            "native"
        } else {
            "ugly"
        });
    }
    dynamic_component::load(source, path, &compiler_config, unsafe {
        generativity::Guard::new(generativity::Id::new())
    })
}