// Copyright 2019-2021 Tauri Programme within The Commons Conservancy
// SPDX-License-Identifier: Apache-2.0
// SPDX-License-Identifier: MIT

use crate::{helpers::template, Result};
use anyhow::Context;
use cargo_mobile::{
  android::{
    config::{Config, Metadata},
    target::Target,
  },
  config::app::DEFAULT_ASSET_DIR,
  os,
  target::TargetTrait as _,
  util::{
    self,
    cli::{Report, TextWrapper},
    prefix_path,
  },
};
use handlebars::Handlebars;
use include_dir::{include_dir, Dir};

use std::{ffi::OsStr, fs, path::Path};

const TEMPLATE_DIR: Dir<'_> = include_dir!("templates/mobile/android");

pub fn gen(
  config: &Config,
  metadata: &Metadata,
  (handlebars, mut map): (Handlebars, template::JsonMap),
  wrapper: &TextWrapper,
) -> Result<()> {
  println!("Installing Android toolchains...");
  Target::install_all().with_context(|| "failed to run rustup")?;
  println!("Generating Android Studio project...");
  let dest = config.project_dir();
  let asset_packs = metadata.asset_packs().unwrap_or_default();

  map.insert(
    "root-dir-rel",
    Path::new(&os::replace_path_separator(
      util::relativize_path(
        config.app().root_dir(),
        config.project_dir().join(config.app().name()),
      )
      .into_os_string(),
    )),
  );
  map.insert("root-dir", config.app().root_dir());
  map.insert("targets", Target::all().values().collect::<Vec<_>>());
  map.insert("target-names", Target::all().keys().collect::<Vec<_>>());
  map.insert(
    "arches",
    Target::all()
      .values()
      .map(|target| target.arch)
      .collect::<Vec<_>>(),
  );
  map.insert("android-app-plugins", metadata.app_plugins());
  map.insert(
    "android-project-dependencies",
    metadata.project_dependencies(),
  );
  map.insert("android-app-dependencies", metadata.app_dependencies());
  map.insert(
    "android-app-dependencies-platform",
    metadata.app_dependencies_platform(),
  );
  map.insert(
    "has-code",
    metadata.project_dependencies().is_some()
      || metadata.app_dependencies().is_some()
      || metadata.app_dependencies_platform().is_some(),
  );
  map.insert(
    "asset-packs",
    asset_packs
      .iter()
      .map(|p| p.name.as_str())
      .collect::<Vec<_>>(),
  );
  map.insert("windows", cfg!(windows));

  let domain = config.app().reverse_domain().replace('.', "/");
  let package_path = format!("java/{}/{}", domain, config.app().name());

  map.insert("package-path", &package_path);

  let mut created_dirs = Vec::new();
  template::render_with_generator(
    &handlebars,
    map.inner(),
    &TEMPLATE_DIR,
    &dest,
    &mut |path| {
      let mut iter = path.iter();
      let root = iter.next().unwrap().to_str().unwrap();
      let path_without_root: std::path::PathBuf = iter.collect();
      let path = match (
        root,
        path.extension().and_then(|o| o.to_str()),
        path_without_root.strip_prefix("src/main"),
      ) {
        ("app" | "buildSrc", Some("kt"), Ok(path)) => {
          let parent = path.parent().unwrap();
          let file_name = path.file_name().unwrap();
          let out_dir = dest
            .join(root)
            .join("src/main")
            .join(&package_path)
            .join(parent);
          out_dir.join(file_name)
        }
        _ => dest.join(path),
      };

      let parent = path.parent().unwrap().to_path_buf();
      if !created_dirs.contains(&parent) {
        fs::create_dir_all(&parent)?;
        created_dirs.push(parent);
      }

      let mut options = fs::OpenOptions::new();

      #[cfg(unix)]
      if path.file_name().unwrap() == OsStr::new("gradlew") {
        use std::os::unix::fs::OpenOptionsExt;
        options.mode(0o755);
      }

      options.create_new(true).write(true).open(path)
    },
  )
  .with_context(|| "failed to process template")?;

  if !asset_packs.is_empty() {
    Report::action_request(
      "When running from Android Studio, you must first set your deployment option to \"APK from app bundle\".",
      "Android Studio will not be able to find your asset packs otherwise. The option can be found under \"Run > Edit Configurations > Deploy\"."
    ).print(wrapper);
  }

  let source_dest = dest.join("app");
  for source in metadata.app_sources() {
    let source_src = config.app().root_dir().join(&source);
    let source_file = source_src
      .file_name()
      .ok_or_else(|| anyhow::anyhow!("asset source {} is invalid", source_src.display()))?;
    fs::copy(&source_src, source_dest.join(source_file)).map_err(|cause| {
      anyhow::anyhow!(
        "failed to copy {} to {}: {}",
        source_src.display(),
        source_dest.display(),
        cause
      )
    })?;
  }

  let dest = prefix_path(dest, "app/src/main/");
  fs::create_dir_all(&dest).map_err(|cause| {
    anyhow::anyhow!(
      "failed to create directory at {}: {}",
      dest.display(),
      cause
    )
  })?;

  let asset_dir = dest.join(DEFAULT_ASSET_DIR);
  if !asset_dir.is_dir() {
    fs::create_dir_all(&asset_dir).map_err(|cause| {
      anyhow::anyhow!(
        "failed to create asset dir {path}: {cause}",
        path = asset_dir.display()
      )
    })?;
  }

  Ok(())
}