use crate::*;
use crate::ratatui::style::Style;

mod column; pub use self::column::*;
mod entry;  pub use self::entry::*;

/// The application state.
pub struct Taggart {
    pub _root:    PathBuf,
    pub entries:  Vec<Entry>,
    pub cursor:   usize,
    pub offset:   usize,
    pub column:   usize,
    pub display:  Measure<TuiOut>,
    /// State of modal dialog of editing field
    pub mode:     Option<Mode>,
    /// Count of changes to items
    pub changes:  usize,
    /// Table columns to display
    pub columns:  Columns<
        fn(&Entry)->Option<Arc<str>>,
        fn(&mut Self, usize, &str),
        fn(&Entry)->Option<Style>,
    >,
}

#[derive(Debug)]
pub enum Mode {
    Help { page: u8 },
    Edit { value: Arc<str>, index: usize, },
    Save { choice: u8, },
    Quit { choice: u8, },
}

impl Taggart {
    pub fn new (root: &impl AsRef<Path>, entries: Vec<Entry>) -> Usually<Self> {
        Ok(Self {
            _root:   root.as_ref().into(),
            cursor:  0,
            offset:  0,
            column:  2,
            display: Measure::new(),
            mode:    None,
            columns: Columns::default(),
            entries,
            changes: 0
        })
    }
    /// Make sure cursor is always in view
    pub(crate) fn clamp (&mut self, min: usize, max: usize) {
        if self.cursor < min {
            self.offset = self.cursor;
        }
        if self.cursor > max {
            self.offset += self.cursor - max;
        }
        if self.offset > self.entries.len().saturating_sub(self.display.h()) {
            self.offset = self.entries.len().saturating_sub(self.display.h())
        }
        if self.cursor >= self.entries.len() {
            self.cursor = self.entries.len().saturating_sub(1)
        }
        if self.column + 1 > self.columns.0.len() {
            self.column = self.columns.0.len().saturating_sub(1)
        }
    }
    /// Count modified entries
    pub(crate) fn count_changes (&mut self) -> usize {
        let mut changes = 0;
        for entry in self.entries.iter() {
            if entry.is_modified() {
                changes += 1;
            }
        }
        self.changes = changes;
        self.changes
    }
    /// Clear all modified tags.
    pub(crate) fn clear_changes (&mut self) {
        for entry in self.entries.iter_mut() {
            if let Metadata::Music {
                modified_tag, ..
            } = &mut *entry.info.write().unwrap() {
                *modified_tag = None;
            }
        }
        self.changes = 0;
    }
}