file.rs

use alloc::vec;

use java_class_proto::{JavaFieldProto, JavaMethodProto};
use java_constants::{FieldAccessFlags, MethodAccessFlags};
use jvm::{ClassInstanceRef, JavaChar, Jvm, Result, runtime::JavaLangString};

use crate::{FileType, RuntimeClassProto, RuntimeContext, classes::java::lang::String};

// class java.io.File
pub struct File;

impl File {
    pub fn as_proto() -> RuntimeClassProto {
        RuntimeClassProto {
            name: "java/io/File",
            parent_class: Some("java/lang/Object"),
            interfaces: vec![],
            methods: vec![
                JavaMethodProto::new("<clinit>", "()V", Self::clinit, MethodAccessFlags::STATIC),
                JavaMethodProto::new("<init>", "(Ljava/lang/String;)V", Self::init, Default::default()),
                JavaMethodProto::new("getPath", "()Ljava/lang/String;", Self::get_path, Default::default()),
                JavaMethodProto::new("exists", "()Z", Self::exists, Default::default()),
                JavaMethodProto::new("isDirectory", "()Z", Self::is_directory, Default::default()),
                JavaMethodProto::new("isFile", "()Z", Self::is_file, Default::default()),
                JavaMethodProto::new("delete", "()Z", Self::delete, Default::default()),
                JavaMethodProto::new("length", "()J", Self::length, Default::default()),
            ],
            fields: vec![
                JavaFieldProto::new(
                    "separatorChar",
                    "C",
                    FieldAccessFlags::PUBLIC | FieldAccessFlags::STATIC | FieldAccessFlags::FINAL,
                ),
                JavaFieldProto::new(
                    "separator",
                    "Ljava/lang/String;",
                    FieldAccessFlags::PUBLIC | FieldAccessFlags::STATIC | FieldAccessFlags::FINAL,
                ),
                JavaFieldProto::new(
                    "pathSeparatorChar",
                    "C",
                    FieldAccessFlags::PUBLIC | FieldAccessFlags::STATIC | FieldAccessFlags::FINAL,
                ),
                JavaFieldProto::new(
                    "pathSeparator",
                    "Ljava/lang/String;",
                    FieldAccessFlags::PUBLIC | FieldAccessFlags::STATIC | FieldAccessFlags::FINAL,
                ),
                JavaFieldProto::new("path", "Ljava/lang/String;", Default::default()),
            ],
            access_flags: Default::default(),
        }
    }

    async fn clinit(jvm: &Jvm, _: &mut RuntimeContext) -> Result<()> {
        tracing::debug!("java.io.File::<clinit>()");

        let separator_char = if cfg!(windows) { '\\' } else { '/' };
        let separator = if cfg!(windows) { "\\" } else { "/" };
        let path_separator_char = if cfg!(windows) { ';' } else { ':' };
        let path_separator = if cfg!(windows) { ";" } else { ":" };

        jvm.put_static_field("java/io/File", "separatorChar", "C", separator_char as JavaChar)
            .await?;
        jvm.put_static_field(
            "java/io/File",
            "separator",
            "Ljava/lang/String;",
            JavaLangString::from_rust_string(jvm, separator).await?,
        )
        .await?;
        jvm.put_static_field("java/io/File", "pathSeparatorChar", "C", path_separator_char as JavaChar)
            .await?;
        jvm.put_static_field(
            "java/io/File",
            "pathSeparator",
            "Ljava/lang/String;",
            JavaLangString::from_rust_string(jvm, path_separator).await?,
        )
        .await?;

        Ok(())
    }

    async fn init(jvm: &Jvm, _: &mut RuntimeContext, mut this: ClassInstanceRef<Self>, pathname: ClassInstanceRef<String>) -> Result<()> {
        tracing::debug!("java.io.File::<init>({this:?}, {pathname:?})");

        let _: () = jvm.invoke_special(&this, "java/lang/Object", "<init>", "()V", ()).await?;

        jvm.put_field(&mut this, "path", "Ljava/lang/String;", pathname).await?;

        Ok(())
    }

    async fn get_path(jvm: &Jvm, _: &mut RuntimeContext, this: ClassInstanceRef<Self>) -> Result<ClassInstanceRef<String>> {
        tracing::debug!("java.io.File::getPath({this:?})");

        jvm.get_field(&this, "path", "Ljava/lang/String;").await
    }

    async fn exists(jvm: &Jvm, context: &mut RuntimeContext, this: ClassInstanceRef<Self>) -> Result<bool> {
        tracing::debug!("java.io.File::exists({this:?})");

        let path = jvm.invoke_virtual(&this, "getPath", "()Ljava/lang/String;", ()).await?;
        let path = JavaLangString::to_rust_string(jvm, &path).await?;

        Ok(context.metadata(&path).await.is_ok())
    }

    async fn is_directory(jvm: &Jvm, context: &mut RuntimeContext, this: ClassInstanceRef<Self>) -> Result<bool> {
        tracing::debug!("java.io.File::isDirectory({this:?})");

        let path = jvm.invoke_virtual(&this, "getPath", "()Ljava/lang/String;", ()).await?;
        let path = JavaLangString::to_rust_string(jvm, &path).await?;

        Ok(context.metadata(&path).await.is_ok_and(|x| x.r#type == FileType::Directory))
    }

    async fn is_file(jvm: &Jvm, context: &mut RuntimeContext, this: ClassInstanceRef<Self>) -> Result<bool> {
        tracing::debug!("java.io.File::isFile({this:?})");

        let path = jvm.invoke_virtual(&this, "getPath", "()Ljava/lang/String;", ()).await?;
        let path = JavaLangString::to_rust_string(jvm, &path).await?;

        Ok(context.metadata(&path).await.is_ok_and(|x| x.r#type == FileType::File))
    }

    async fn delete(jvm: &Jvm, context: &mut RuntimeContext, this: ClassInstanceRef<Self>) -> Result<bool> {
        tracing::debug!("java.io.File::delete({this:?})");

        let path = jvm.invoke_virtual(&this, "getPath", "()Ljava/lang/String;", ()).await?;
        let path = JavaLangString::to_rust_string(jvm, &path).await?;

        Ok(context.unlink(&path).await.is_ok())
    }

    async fn length(jvm: &Jvm, context: &mut RuntimeContext, this: ClassInstanceRef<Self>) -> Result<i64> {
        tracing::debug!("java.io.File::length({this:?})");

        let path = jvm.invoke_virtual(&this, "getPath", "()Ljava/lang/String;", ()).await?;
        let path = JavaLangString::to_rust_string(jvm, &path).await?;

        // File.length() is 0 when the file does not exist
        Ok(context.metadata(&path).await.map_or(0, |x| x.size as _))
    }
}