use crossterm::event::{KeyCode, KeyEvent};
use std::sync::atomic::Ordering;

use super::{InputContext, InputResult};
use crate::commands::AppCommand;
use crate::state::{ConfirmAction, Modal, OptionsFocus};

pub(super) fn handle_options_page(ctx: &mut InputContext, key: KeyEvent) -> InputResult {
    match key.code {
        KeyCode::Char('q') => {
            ctx.dispatch(AppCommand::OpenModal(Modal::Confirm {
                action: ConfirmAction::Quit,
                selected: false,
            }));
        }
        KeyCode::Down | KeyCode::Tab => ctx.dispatch(AppCommand::OptionsNextFocus),
        KeyCode::Up | KeyCode::BackTab => ctx.dispatch(AppCommand::OptionsPrevFocus),
        KeyCode::Left | KeyCode::Right => {
            match ctx.app.options.focus {
                OptionsFocus::ColorScheme => {
                    let new_scheme = if key.code == KeyCode::Left {
                        ctx.app.ui.color_scheme.prev()
                    } else {
                        ctx.app.ui.color_scheme.next()
                    };
                    ctx.dispatch(AppCommand::SetColorScheme(new_scheme));
                }
                OptionsFocus::HueRotation => {
                    let delta = if key.code == KeyCode::Left { -5.0 } else { 5.0 };
                    let new_rotation = (ctx.app.ui.hue_rotation + delta).rem_euclid(360.0);
                    ctx.dispatch(AppCommand::SetHueRotation(new_rotation));
                }
                OptionsFocus::RefreshRate => ctx.dispatch(AppCommand::ToggleRefreshRate),
                OptionsFocus::RuntimeHighlight => {
                    ctx.dispatch(AppCommand::ToggleRuntimeHighlight);
                }
                OptionsFocus::ShowScope => {
                    ctx.dispatch(AppCommand::ToggleScope);
                }
                OptionsFocus::ShowSpectrum => {
                    ctx.dispatch(AppCommand::ToggleSpectrum);
                }
                OptionsFocus::ShowCompletion => {
                    ctx.dispatch(AppCommand::ToggleCompletion);
                }
                OptionsFocus::LinkEnabled => ctx.link.set_enabled(!ctx.link.is_enabled()),
                OptionsFocus::StartStopSync => ctx
                    .link
                    .set_start_stop_sync_enabled(!ctx.link.is_start_stop_sync_enabled()),
                OptionsFocus::Quantum => {
                    let delta = if key.code == KeyCode::Left { -1.0 } else { 1.0 };
                    ctx.link.set_quantum(ctx.link.quantum() + delta);
                }
                OptionsFocus::MidiOutput0
                | OptionsFocus::MidiOutput1
                | OptionsFocus::MidiOutput2
                | OptionsFocus::MidiOutput3 => {
                    let slot = match ctx.app.options.focus {
                        OptionsFocus::MidiOutput0 => 0,
                        OptionsFocus::MidiOutput1 => 1,
                        OptionsFocus::MidiOutput2 => 2,
                        OptionsFocus::MidiOutput3 => 3,
                        _ => 0,
                    };
                    let all_devices = crate::midi::list_midi_outputs();
                    let available: Vec<(usize, &crate::midi::MidiDeviceInfo)> = all_devices
                        .iter()
                        .enumerate()
                        .filter(|(idx, _)| {
                            ctx.app.midi.selected_outputs[slot] == Some(*idx)
                                || !ctx
                                    .app
                                    .midi
                                    .selected_outputs
                                    .iter()
                                    .enumerate()
                                    .any(|(s, sel)| s != slot && *sel == Some(*idx))
                        })
                        .collect();
                    let total_options = available.len() + 1;
                    let current_pos = ctx.app.midi.selected_outputs[slot]
                        .and_then(|idx| available.iter().position(|(i, _)| *i == idx))
                        .map(|p| p + 1)
                        .unwrap_or(0);
                    let new_pos = if key.code == KeyCode::Left {
                        if current_pos == 0 {
                            total_options - 1
                        } else {
                            current_pos - 1
                        }
                    } else {
                        (current_pos + 1) % total_options
                    };
                    if new_pos == 0 {
                        ctx.app.midi.disconnect_output(slot);
                        ctx.dispatch(AppCommand::SetStatus(format!(
                            "MIDI output {slot}: disconnected"
                        )));
                    } else {
                        let (device_idx, device) = available[new_pos - 1];
                        if ctx.app.midi.connect_output(slot, device_idx).is_ok() {
                            ctx.dispatch(AppCommand::SetStatus(format!(
                                "MIDI output {}: {}",
                                slot, device.name
                            )));
                        }
                    }
                }
                OptionsFocus::MidiInput0
                | OptionsFocus::MidiInput1
                | OptionsFocus::MidiInput2
                | OptionsFocus::MidiInput3 => {
                    let slot = match ctx.app.options.focus {
                        OptionsFocus::MidiInput0 => 0,
                        OptionsFocus::MidiInput1 => 1,
                        OptionsFocus::MidiInput2 => 2,
                        OptionsFocus::MidiInput3 => 3,
                        _ => 0,
                    };
                    let all_devices = crate::midi::list_midi_inputs();
                    let available: Vec<(usize, &crate::midi::MidiDeviceInfo)> = all_devices
                        .iter()
                        .enumerate()
                        .filter(|(idx, _)| {
                            ctx.app.midi.selected_inputs[slot] == Some(*idx)
                                || !ctx
                                    .app
                                    .midi
                                    .selected_inputs
                                    .iter()
                                    .enumerate()
                                    .any(|(s, sel)| s != slot && *sel == Some(*idx))
                        })
                        .collect();
                    let total_options = available.len() + 1;
                    let current_pos = ctx.app.midi.selected_inputs[slot]
                        .and_then(|idx| available.iter().position(|(i, _)| *i == idx))
                        .map(|p| p + 1)
                        .unwrap_or(0);
                    let new_pos = if key.code == KeyCode::Left {
                        if current_pos == 0 {
                            total_options - 1
                        } else {
                            current_pos - 1
                        }
                    } else {
                        (current_pos + 1) % total_options
                    };
                    if new_pos == 0 {
                        ctx.app.midi.disconnect_input(slot);
                        ctx.dispatch(AppCommand::SetStatus(format!(
                            "MIDI input {slot}: disconnected"
                        )));
                    } else {
                        let (device_idx, device) = available[new_pos - 1];
                        if ctx.app.midi.connect_input(slot, device_idx).is_ok() {
                            ctx.dispatch(AppCommand::SetStatus(format!(
                                "MIDI input {}: {}",
                                slot, device.name
                            )));
                        }
                    }
                }
            }
            ctx.app.save_settings(ctx.link);
        }
        KeyCode::Char(' ') => {
            ctx.dispatch(AppCommand::TogglePlaying);
            ctx.playing
                .store(ctx.app.playback.playing, Ordering::Relaxed);
        }
        KeyCode::Char('?') => {
            ctx.dispatch(AppCommand::OpenModal(Modal::KeybindingsHelp { scroll: 0 }));
        }
        _ => {}
    }
    InputResult::Continue
}