use crate::*;
/// Browses for phrase to import/export
#[derive(Debug, Clone)]
pub struct FileBrowser {
    pub cwd:    PathBuf,
    pub dirs:   Vec<(OsString, String)>,
    pub files:  Vec<(OsString, String)>,
    pub filter: String,
    pub index:  usize,
    pub scroll: usize,
    pub size:   Measure<Tui>
}
/// Commands supported by [FileBrowser]
#[derive(Debug, Clone, PartialEq)]
pub enum FileBrowserCommand {
    Begin,
    Cancel,
    Confirm,
    Select(usize),
    Chdir(PathBuf),
    Filter(String),
}
render!(Tui: (self: FileBrowser) => /*Stack::down(|add|{
    let mut i = 0;
    for (_, name) in self.dirs.iter() {
        if i >= self.scroll {
            add(&Tui::bold(i == self.index, name.as_str()))?;
        }
        i += 1;
    }
    for (_, name) in self.files.iter() {
        if i >= self.scroll {
            add(&Tui::bold(i == self.index, name.as_str()))?;
        }
        i += 1;
    }
    add(&format!("{}/{i}", self.index))?;
    Ok(())
})*/"todo");
impl FileBrowser {
    pub fn new (cwd: Option<PathBuf>) -> Usually<Self> {
        let cwd = if let Some(cwd) = cwd { cwd } else { std::env::current_dir()? };
        let mut dirs  = vec![];
        let mut files = vec![];
        for entry in std::fs::read_dir(&cwd)? {
            let entry = entry?;
            let name = entry.file_name();
            let decoded = name.clone().into_string().unwrap_or_else(|_|"<unreadable>".to_string());
            let meta = entry.metadata()?;
            if meta.is_dir() {
                dirs.push((name, format!("📁 {decoded}")));
            } else if meta.is_file() {
                files.push((name, format!("📄 {decoded}")));
            }
        }
        Ok(Self {
            cwd,
            dirs,
            files,
            filter: "".to_string(),
            index:  0,
            scroll: 0,
            size:   Measure::new(),
        })
    }
    pub fn len (&self) -> usize {
        self.dirs.len() + self.files.len()
    }
    pub fn is_dir (&self) -> bool {
        self.index < self.dirs.len()
    }
    pub fn is_file (&self) -> bool {
        self.index >= self.dirs.len()
    }
    pub fn path (&self) -> PathBuf {
        self.cwd.join(if self.is_dir() {
            &self.dirs[self.index].0
        } else if self.is_file() {
            &self.files[self.index - self.dirs.len()].0
        } else {
            unreachable!()
        })
    }
    pub fn chdir (&self) -> Usually<Self> {
        Self::new(Some(self.path()))
    }
}
command!(|self: FileBrowserCommand, state: PoolModel|{
    use PoolMode::*;
    use FileBrowserCommand::*;
    let mode = &mut state.mode;
    match mode {
        Some(Import(index, ref mut browser)) => match self {
            Cancel => { *mode = None; },
            Chdir(cwd) => { *mode = Some(Import(*index, FileBrowser::new(Some(cwd))?)); },
            Select(index) => { browser.index = index; },
            Confirm => if browser.is_file() {
                let index = *index;
                let path  = browser.path();
                *mode = None;
                PhrasePoolCommand::Import(index, path).execute(state)?;
            } else if browser.is_dir() {
                *mode = Some(Import(*index, browser.chdir()?));
            },
            _ => todo!(),
        },
        Some(Export(index, ref mut browser)) => match self {
            Cancel => { *mode = None; },
            Chdir(cwd) => { *mode = Some(Export(*index, FileBrowser::new(Some(cwd))?)); },
            Select(index) => { browser.index = index; },
            _ => unreachable!()
        },
        _ => unreachable!(),
    };
    None
});
input_to_command!(FileBrowserCommand: |state: PoolModel, input: Event|{
    use FileBrowserCommand::*;
    use KeyCode::{Up, Down, Left, Right, Enter, Esc, Backspace, Char};
    if let Some(PoolMode::Import(_index, browser)) = &state.mode {
        match input {
            kpat!(Up)        => Select(browser.index.overflowing_sub(1).0
                                    .min(browser.len().saturating_sub(1))),
            kpat!(Down)      => Select(browser.index.saturating_add(1)
                                    % browser.len()),
            kpat!(Right)     => Chdir(browser.cwd.clone()),
            kpat!(Left)      => Chdir(browser.cwd.clone()),
            kpat!(Enter)     => Confirm,
            kpat!(Char(_))   => { todo!() },
            kpat!(Backspace) => { todo!() },
            kpat!(Esc)       => Cancel,
            _ => return None
        }
    } else if let Some(PoolMode::Export(_index, browser)) = &state.mode {
        match input {
            kpat!(Up)        => Select(browser.index.overflowing_sub(1).0
                                    .min(browser.len())),
            kpat!(Down)      => Select(browser.index.saturating_add(1)
                                    % browser.len()),
            kpat!(Right)     => Chdir(browser.cwd.clone()),
            kpat!(Left)      => Chdir(browser.cwd.clone()),
            kpat!(Enter)     => Confirm,
            kpat!(Char(_))   => { todo!() },
            kpat!(Backspace) => { todo!() },
            kpat!(Esc)       => Cancel,
            _ => return None
        }
    } else {
        unreachable!()
    }
});