creeper 1.0.0-alpha.5

use std::{
    collections::{BTreeSet, HashMap},
    fmt::Display,
    marker::PhantomData,
    path::{Path, PathBuf},
    str::FromStr,
    sync::OnceLock,
};

use anyhow::{anyhow, bail};
use inquire::{
    Confirm, Text,
    validator::{StringValidator, Validation},
};
use semver::{Version, VersionReq};
use serde::{Deserialize, Serialize, de::DeserializeOwned};
use tokio::{
    fs::{
        File, copy, create_dir_all, metadata, read_to_string, remove_dir_all, remove_file, rename,
        set_permissions, try_exists, write,
    },
    sync::RwLock,
    task::spawn_blocking,
};
use tracing::{info, trace};

pub async fn mv(src: impl AsRef<Path>, dst: impl AsRef<Path>) -> anyhow::Result<()> {
    if let Some(parent) = dst.as_ref().parent() {
        create_dir_all(parent).await?;
    }
    File::create(&dst).await?;

    let rename = rename(&src, &dst).await;
    match rename {
        Ok(_) => return Ok(()),
        Err(e) if e.kind() == std::io::ErrorKind::CrossesDevices => {}
        e => e?,
    }
    copy(&src, &dst).await?;
    remove_file(&src).await?;
    Ok(())
}

pub async fn set_readonly(path: impl AsRef<Path>) -> anyhow::Result<()> {
    let path = path.as_ref();

    let metadata = metadata(path).await?;

    let mut perm = metadata.permissions();
    perm.set_readonly(true);

    set_permissions(path, perm).await?;

    trace!("set {} to readonly", path.display());

    Ok(())
}

/// Parse the first section of an RFC 822-like format.
///
/// # Note
///
/// TODO: this function does not yet guarantee complete support for the RFC 822 and there may exist behavioral difference in edge cases.
pub fn rfc822_first_section(s: &str) -> anyhow::Result<HashMap<&str, &str>> {
    let mut map = HashMap::new();

    let lines = s.lines().take_while(|l| !l.is_empty());

    for line in lines {
        let (key, value) = line.split_once(": ").ok_or(anyhow!("invalid line"))?;
        map.insert(key, value);
    }

    Ok(map)
}

#[derive(Clone, Serialize, Deserialize)]
pub struct JarManifest {
    pub manifest_version: String,
    pub implementation_version: Option<String>,
    pub main_class: Option<String>,
}

impl FromStr for JarManifest {
    type Err = anyhow::Error;

    fn from_str(s: &str) -> Result<Self, Self::Err> {
        let map = rfc822_first_section(s)?;

        let manifest_version = map
            .get("Manifest-Version")
            .ok_or(anyhow!("missing field Manifest-Version"))?
            .to_string();
        let implementation_version = map.get("Implementation-Version").map(|s| s.to_string());
        let main_class = map.get("Main-Class").map(|s| s.to_string());

        Ok(Self {
            manifest_version,
            implementation_version,
            main_class,
        })
    }
}

/// Prompt the user to confirm the removal of a file or directory, and remove it if confirmed.
pub async fn prompt_remove(path: impl AsRef<Path>) -> anyhow::Result<()> {
    let path = path.as_ref();
    let confirm = Confirm::new(&format!("Remove {}?", path.display())).prompt()?;
    if !confirm {
        bail!("aborted by user");
    }
    info!("removing {}", path.display());
    remove_dir_all(path).await?;
    Ok(())
}

pub struct TomlFile<T>
where
    T: Clone + Serialize + DeserializeOwned,
{
    cache: RwLock<OnceLock<Option<T>>>,
}

impl<T> TomlFile<T>
where
    T: Clone + Serialize + DeserializeOwned,
{
    pub fn new() -> Self {
        Self {
            cache: RwLock::new(OnceLock::new()),
        }
    }

    pub async fn read(&self, path: impl AsRef<Path>) -> anyhow::Result<Option<T>> {
        if let Some(value) = self.cache.read().await.get() {
            return Ok(value.clone());
        }

        let value = if try_exists(&path).await? {
            let toml = read_to_string(&path).await?;
            Some(toml::from_str(&toml)?)
        } else {
            None
        };

        let value = self.cache.write().await.get_or_init(|| value).clone();

        Ok(value)
    }

    pub async fn write(&self, path: impl AsRef<Path>, value: Option<T>) -> anyhow::Result<()> {
        let path = path.as_ref();

        *self.cache.write().await = value.clone().into();

        if let Some(value) = value {
            let toml = toml::to_string(&value)?;

            if let Some(parent) = path.parent() {
                create_dir_all(parent).await?;
            }

            write(path, toml).await?;
        } else {
            if try_exists(path).await? {
                remove_file(path).await?;
            }
        }

        Ok(())
    }
}

pub async fn prompt_valid<T>(message: &str) -> anyhow::Result<T>
where
    T: FromStr + Send + 'static,
    <T as FromStr>::Err: Display,
{
    let message = message.to_string();
    let value = spawn_blocking(move || blocking_prompt_valid::<T>(&message)).await??;
    Ok(value)
}

pub async fn confirm_or_prompt<T>(
    value: T,
    confirm_msg: &str,
    prompt_msg: &str,
) -> anyhow::Result<T>
where
    T: FromStr + Send + 'static,
    <T as FromStr>::Err: Display,
{
    let confirm_msg = confirm_msg.to_string();
    let prompt_msg = prompt_msg.to_string();

    let value =
        spawn_blocking(move || blocking_confirm_or_prompt(value, &confirm_msg, &prompt_msg))
            .await??;

    Ok(value)
}

pub fn blocking_prompt_valid<T>(message: &str) -> anyhow::Result<T>
where
    T: FromStr,
    <T as FromStr>::Err: Display,
{
    struct Validator<T>(PhantomData<T>);

    impl<T> Clone for Validator<T> {
        fn clone(&self) -> Self {
            Self(self.0.clone())
        }
    }

    impl<T> StringValidator for Validator<T>
    where
        T: FromStr,
        <T as FromStr>::Err: Display,
    {
        fn validate(
            &self,
            input: &str,
        ) -> Result<inquire::validator::Validation, inquire::CustomUserError> {
            let valid = match input.parse::<T>() {
                Ok(_) => Validation::Valid,
                Err(e) => Validation::Invalid(e.to_string().into()),
            };
            Ok(valid)
        }
    }

    let valid = Validator::<T>(PhantomData);

    let value = Text::new(message)
        .with_validator(valid)
        .prompt()?
        .parse()
        .map_err(|_| unreachable!())
        .unwrap();

    Ok(value)
}

pub fn blocking_confirm_or_prompt<T>(
    value: T,
    confirm_msg: &str,
    prompt_msg: &str,
) -> anyhow::Result<T>
where
    T: FromStr,
    <T as FromStr>::Err: Display,
{
    let confirm = Confirm::new(confirm_msg).prompt()?;

    if confirm {
        return Ok(value);
    }

    let value = blocking_prompt_valid(prompt_msg)?;

    Ok(value)
}

pub async fn parse_or_prompt<T>(s: &str, desc: &str) -> anyhow::Result<T>
where
    T: FromStr + Send + 'static,
    <T as FromStr>::Err: Display,
{
    let s = s.to_owned();
    let desc = desc.to_owned();

    let value = spawn_blocking(move || blocking_parse_or_prompt(&s, &desc)).await??;

    Ok(value)
}

pub fn blocking_parse_or_prompt<T>(s: &str, desc: &str) -> anyhow::Result<T>
where
    T: FromStr,
    <T as FromStr>::Err: Display,
{
    if let Ok(value) = s.parse() {
        return blocking_confirm_or_prompt(
            value,
            &format!("Use {s} as {desc}?"),
            &format!("Input a new {desc}:"),
        );
    }

    let value = blocking_prompt_valid(&format!("{s} is not valid {desc}, input one instead:"))?;

    Ok(value)
}

pub async fn prompt_save(content: impl AsRef<[u8]>, path: impl AsRef<Path>) -> anyhow::Result<()> {
    let content = content.as_ref();
    let path = path.as_ref();

    let message = format!("Save {} bytes to file?", content.len());

    let confirm =
        spawn_blocking(move || Confirm::new(&message).with_default(false).prompt()).await??;

    if !confirm {
        return Ok(());
    }

    let default = path.display().to_string();

    let path = spawn_blocking(move || {
        Text::new("Enter the path to save to")
            .with_default(&default)
            .prompt()
    })
    .await??;

    let path = PathBuf::from(path);

    if let Some(parent) = path.parent() {
        create_dir_all(parent).await?;
    }

    write(&path, content).await?;

    Ok(())
}

pub async fn symlink_auto(
    original: impl AsRef<Path>,
    link: impl AsRef<Path>,
) -> anyhow::Result<()> {
    #[cfg(unix)]
    {
        use tokio::fs::symlink;

        symlink(original, link).await?;

        Ok(())
    }

    #[cfg(windows)]
    {
        use tokio::fs::{symlink_dir, symlink_file};

        let original = original.as_ref();

        if !try_exists(original).await? {
            bail!(
                "cannot create symlink on windows: original path {} does not exist",
                original.display()
            );
        }

        let meta = metadata(original).await?;

        if meta.is_dir() {
            symlink_dir(original, link).await?;
        } else if meta.is_file() {
            symlink_file(original, link).await?;
        } else {
            panic!();
        }

        Ok(())
    }
}

pub fn rebuild_req(
    versions: BTreeSet<Version>,
    univ: BTreeSet<Version>,
) -> anyhow::Result<VersionReq> {
    if !versions.is_subset(&univ) {
        bail!("versions not subset of universe");
    }

    if versions.is_empty() {
        // empty set
        let req = format!("<1.0.0, >=1.0.0").parse().unwrap();
        return Ok(req);
    }

    let start = versions.first().unwrap();

    let end = univ.range(start..).find(|v| !versions.contains(v));

    let end = match end {
        Some(v) => v,
        None => {
            let end = univ.last().unwrap();
            return Ok(format!(">={start}, <={end}",).parse().unwrap());
        }
    };

    if end < versions.last().unwrap() {
        bail!("versions contains a gap");
    }

    let req = format!(">={start}, <{end}").parse().unwrap();

    Ok(req)
}