//! Creating, loading, deleting, moving, copying and pasting files and their elements.

use gpx_engine::api;
use wasm_bindgen::prelude::*;

use crate::convert::*;
use crate::ids::*;
use crate::session::*;
use crate::ts::*;

// File commands

/// Creates a file and selects it. With `route`, it starts with a route. With `lng` and `lat`, it
/// starts with a segment that holds that trackpoint (at `ele`, 0 by default): the one of its route
/// with `route`, of a track otherwise.
#[wasm_bindgen]
pub fn new_file(
    name: &str,
    lng: Option<f64>,
    lat: Option<f64>,
    ele: Option<f64>,
    route: bool,
) -> Outcome {
    run(|e| api::new_file(e, name, lng, lat, ele, route))
}

/// Loads files as a single command (one undo step). The files are in `data`, one after the
/// other, `lengths` being the number of bytes of each one. `names`: the name of each file when
/// its data has none (the name on disk, without extension). The files that cannot be read are
/// skipped, the first one that was read is selected.
#[wasm_bindgen]
pub fn load_files(data: &[u8], lengths: &[u32], names: Vec<String>) -> Outcome {
    let lengths: Vec<usize> = lengths.iter().map(|length| *length as usize).collect();
    run(|e| api::load_files(e, data, &lengths, &names))
}

#[wasm_bindgen]
pub fn duplicate() -> Outcome {
    run(api::duplicate)
}

/// Deletes the selected elements. With `whole_files`, the files holding the selected elements are
/// deleted instead, even if only a track or a waypoint is selected.
#[wasm_bindgen]
pub fn delete(whole_files: bool) -> Outcome {
    run(|e| api::delete(e, whole_files))
}

#[wasm_bindgen]
pub fn delete_all() -> Outcome {
    run(api::delete_all)
}

/// Moves the files to `index` among the other files, in the given order (not undoable).
/// `file_ids_bytes`: concatenated 16-byte UUIDs.
#[wasm_bindgen]
pub fn reorder(file_ids_bytes: &[u8], index: usize) -> Outcome {
    match uuid_list(file_ids_bytes) {
        Some(ids) => run(|e| api::reorder(e, &ids, index)),
        None => fail("the file ids are not a list of UUIDs"),
    }
}

// Clipboard

/// Puts the selected elements in the clipboard. Nothing happens when nothing is selected.
#[wasm_bindgen]
pub fn copy() -> Outcome {
    run(api::copy)
}

/// Like `copy`, but the elements are moved when they are pasted.
#[wasm_bindgen]
pub fn cut() -> Outcome {
    run(api::cut)
}

/// Pastes the clipboard according to the selection (see `can_paste`). What is pasted is always
/// the elements as they were when they were copied or cut, even if they were changed or deleted
/// since. It can be pasted several times: what was copied is copied again, what was cut is moved
/// the first time (and the clipboard is not cut after that), then it is copied.
#[wasm_bindgen]
pub fn paste() -> Outcome {
    run(api::paste)
}

/// Whether the clipboard can be pasted with the current selection.
#[wasm_bindgen]
pub fn can_paste() -> bool {
    with_engine(api::can_paste).unwrap_or(false)
}

/// Moves elements (given as a `Selection`) to a place of the file tree, keeping their ids, like
/// dragging and dropping them does. The moved elements are selected.
///
/// Files can only go among the files; tracks among the files (each becomes a file) or the tracks
/// of a file; segments among the files (each becomes a file), the tracks of a file (each becomes
/// a track) or the segments of a track; waypoints, or all the waypoints of a file, among the
/// waypoints of a file.
#[wasm_bindgen]
pub fn move_elements(what: Selection, to: MoveTarget) -> Outcome {
    // a negative index is the start, an infinite one is the end
    match from_js::<api::Selection>(&what).zip(from_js::<api::MoveTarget>(&to)) {
        Some((what, to)) => run(|e| api::move_elements(e, what, to)),
        None => fail("the elements or the target are not valid"),
    }
}