#![cfg(unix)]

use insta::assert_snapshot;
use zellij_integration_tests::{
    claim_first_terminal_and_wait_for_prompt, keys, normalized, start_zellij, FakePtyHandle,
    TestSession,
};

const LAST_LINE: &str = "line40";

fn fill_pane_past_viewport(zellij: &TestSession) -> FakePtyHandle {
    let terminal = claim_first_terminal_and_wait_for_prompt(zellij);
    for line in 1..=40 {
        terminal.output(format!("line{:02}\r\n", line).as_bytes());
    }
    zellij.wait_until("pane filled past its viewport", |grid_snapshot| {
        grid_snapshot.contains(LAST_LINE)
    });
    terminal
}

#[test]
fn page_scroll_up() {
    let mut zellij = start_zellij();
    fill_pane_past_viewport(&zellij);

    zellij.send_stdin(&keys::ctrl('s'));
    zellij.send_stdin(&keys::ctrl('b'));

    let grid_snapshot = zellij.wait_until("scrolled up by a page", |grid_snapshot| {
        grid_snapshot.contains("PgDn|PgUp")
            && !grid_snapshot.contains(LAST_LINE)
            && grid_snapshot.contains("SCROLL 19/")
    });
    assert_snapshot!(normalized(&grid_snapshot));
    zellij.quit();
}

#[test]
fn page_scroll_down() {
    let mut zellij = start_zellij();
    fill_pane_past_viewport(&zellij);

    zellij.send_stdin(&keys::ctrl('s'));
    zellij.send_stdin(&keys::ctrl('b'));
    zellij.wait_until("scrolled up by a page", |grid_snapshot| {
        grid_snapshot.contains("PgDn|PgUp") && !grid_snapshot.contains(LAST_LINE)
    });

    zellij.send_stdin(&keys::ctrl('f'));

    let grid_snapshot =
        zellij.wait_until("scrolled back down toward the bottom", |grid_snapshot| {
            grid_snapshot.contains("line39")
                && grid_snapshot.contains("PgDn|PgUp")
                && grid_snapshot.contains("SCROLL 0/")
        });
    assert_snapshot!(normalized(&grid_snapshot));
    zellij.quit();
}

#[test]
fn half_page_scroll_up() {
    let mut zellij = start_zellij();
    fill_pane_past_viewport(&zellij);

    zellij.send_stdin(&keys::ctrl('s'));
    zellij.send_stdin(&keys::key('u'));

    let grid_snapshot = zellij.wait_until("scrolled up by half a page", |grid_snapshot| {
        grid_snapshot.contains("PgDn|PgUp")
            && !grid_snapshot.contains(LAST_LINE)
            && grid_snapshot.contains("SCROLL 10/")
    });
    assert_snapshot!(normalized(&grid_snapshot));
    zellij.quit();
}

#[test]
fn half_page_scroll_down() {
    let mut zellij = start_zellij();
    fill_pane_past_viewport(&zellij);

    zellij.send_stdin(&keys::ctrl('s'));
    zellij.send_stdin(&keys::key('u'));
    zellij.wait_until("scrolled up by half a page", |grid_snapshot| {
        grid_snapshot.contains("PgDn|PgUp") && !grid_snapshot.contains(LAST_LINE)
    });

    zellij.send_stdin(&keys::key('d'));

    let grid_snapshot =
        zellij.wait_until("scrolled back down toward the bottom", |grid_snapshot| {
            grid_snapshot.contains("line39")
                && grid_snapshot.contains("PgDn|PgUp")
                && grid_snapshot.contains("SCROLL 0/")
        });
    assert_snapshot!(normalized(&grid_snapshot));
    zellij.quit();
}

#[test]
fn scroll_down_one_line() {
    let mut zellij = start_zellij();
    fill_pane_past_viewport(&zellij);

    zellij.send_stdin(&keys::ctrl('s'));
    zellij.send_stdin(&keys::key('k'));
    zellij.send_stdin(&keys::key('k'));
    zellij.wait_until("scrolled up two lines", |grid_snapshot| {
        grid_snapshot.contains("SCROLL 2/")
    });

    zellij.send_stdin(&keys::key('j'));

    let grid_snapshot = zellij.wait_until("scrolled back down one line", |grid_snapshot| {
        grid_snapshot.contains("SCROLL 1/") && grid_snapshot.contains("PgDn|PgUp")
    });
    assert_snapshot!(normalized(&grid_snapshot));
    zellij.quit();
}

#[test]
fn scroll_to_bottom() {
    let mut zellij = start_zellij();
    fill_pane_past_viewport(&zellij);

    zellij.send_stdin(&keys::ctrl('s'));
    zellij.send_stdin(&keys::ctrl('b'));
    zellij.wait_until("scrolled up by a page", |grid_snapshot| {
        grid_snapshot.contains("PgDn|PgUp") && !grid_snapshot.contains(LAST_LINE)
    });

    zellij.send_stdin(&keys::ctrl('c'));

    let grid_snapshot =
        zellij.wait_until("returned to the bottom in normal mode", |grid_snapshot| {
            grid_snapshot.status_bar_appears()
                && grid_snapshot.contains(LAST_LINE)
                && grid_snapshot.contains("SCROLL 0/")
        });
    assert_snapshot!(normalized(&grid_snapshot));
    zellij.quit();
}