use std::sync::Arc;

use client::TelemetrySettings;
use editor_mode_setting::{EditorMode, EditorModeSetting};
use fs::Fs;
use gpui::{App, IntoElement};
use settings::{BaseKeymap, Settings, update_settings_file};
use theme::{
    Appearance, SystemAppearance, ThemeMode, ThemeName, ThemeRegistry, ThemeSelection,
    ThemeSettings,
};
use ui::{
    ParentElement as _, StatefulInteractiveElement, SwitchField, ToggleButtonGroup,
    ToggleButtonSimple, ToggleButtonWithIcon, prelude::*, rems_from_px,
};

use crate::theme_preview::{ThemePreviewStyle, ThemePreviewTile};

const LIGHT_THEMES: [&str; 3] = ["One Light", "Ayu Light", "Gruvbox Light"];
const DARK_THEMES: [&str; 3] = ["One Dark", "Ayu Dark", "Gruvbox Dark"];
const FAMILY_NAMES: [SharedString; 3] = [
    SharedString::new_static("One"),
    SharedString::new_static("Ayu"),
    SharedString::new_static("Gruvbox"),
];

fn get_theme_family_themes(theme_name: &str) -> Option<(&'static str, &'static str)> {
    for i in 0..LIGHT_THEMES.len() {
        if LIGHT_THEMES[i] == theme_name || DARK_THEMES[i] == theme_name {
            return Some((LIGHT_THEMES[i], DARK_THEMES[i]));
        }
    }
    None
}

fn render_theme_section(tab_index: &mut isize, cx: &mut App) -> impl IntoElement {
    let theme_selection = ThemeSettings::get_global(cx).theme_selection.clone();
    let system_appearance = theme::SystemAppearance::global(cx);
    let theme_selection = theme_selection.unwrap_or_else(|| ThemeSelection::Dynamic {
        mode: match *system_appearance {
            Appearance::Light => ThemeMode::Light,
            Appearance::Dark => ThemeMode::Dark,
        },
        light: ThemeName("One Light".into()),
        dark: ThemeName("One Dark".into()),
    });

    let theme_mode = theme_selection
        .mode()
        .unwrap_or_else(|| match *system_appearance {
            Appearance::Light => ThemeMode::Light,
            Appearance::Dark => ThemeMode::Dark,
        });

    return v_flex()
        .gap_2()
        .child(
            h_flex().justify_between().child(Label::new("Theme")).child(
                ToggleButtonGroup::single_row(
                    "theme-selector-onboarding-dark-light",
                    [ThemeMode::Light, ThemeMode::Dark, ThemeMode::System].map(|mode| {
                        const MODE_NAMES: [SharedString; 3] = [
                            SharedString::new_static("Light"),
                            SharedString::new_static("Dark"),
                            SharedString::new_static("System"),
                        ];
                        ToggleButtonSimple::new(
                            MODE_NAMES[mode as usize].clone(),
                            move |_, _, cx| {
                                write_mode_change(mode, cx);
                            },
                        )
                    }),
                )
                .tab_index(tab_index)
                .selected_index(theme_mode as usize)
                .style(ui::ToggleButtonGroupStyle::Outlined)
                .width(rems_from_px(3. * 64.)),
            ),
        )
        .child(
            h_flex()
                .gap_4()
                .justify_between()
                .children(render_theme_previews(tab_index, &theme_selection, cx)),
        );

    fn render_theme_previews(
        tab_index: &mut isize,
        theme_selection: &ThemeSelection,
        cx: &mut App,
    ) -> [impl IntoElement; 3] {
        let system_appearance = SystemAppearance::global(cx);
        let theme_registry = ThemeRegistry::global(cx);

        let theme_seed = 0xBEEF as f32;
        let theme_mode = theme_selection
            .mode()
            .unwrap_or_else(|| match *system_appearance {
                Appearance::Light => ThemeMode::Light,
                Appearance::Dark => ThemeMode::Dark,
            });
        let appearance = match theme_mode {
            ThemeMode::Light => Appearance::Light,
            ThemeMode::Dark => Appearance::Dark,
            ThemeMode::System => *system_appearance,
        };
        let current_theme_name = theme_selection.theme(appearance);

        let theme_names = match appearance {
            Appearance::Light => LIGHT_THEMES,
            Appearance::Dark => DARK_THEMES,
        };

        let themes = theme_names.map(|theme| theme_registry.get(theme).unwrap());

        [0, 1, 2].map(|index| {
            let theme = &themes[index];
            let is_selected = theme.name == current_theme_name;
            let name = theme.name.clone();
            let colors = cx.theme().colors();

            v_flex()
                .w_full()
                .items_center()
                .gap_1()
                .child(
                    h_flex()
                        .id(name)
                        .relative()
                        .w_full()
                        .border_2()
                        .border_color(colors.border_transparent)
                        .rounded(ThemePreviewTile::ROOT_RADIUS)
                        .map(|this| {
                            if is_selected {
                                this.border_color(colors.border_selected)
                            } else {
                                this.opacity(0.8).hover(|s| s.border_color(colors.border))
                            }
                        })
                        .tab_index({
                            *tab_index += 1;
                            *tab_index - 1
                        })
                        .focus(|mut style| {
                            style.border_color = Some(colors.border_focused);
                            style
                        })
                        .on_click({
                            let theme_name = theme.name.clone();
                            move |_, _, cx| {
                                write_theme_change(theme_name.clone(), theme_mode, cx);
                            }
                        })
                        .map(|this| {
                            if theme_mode == ThemeMode::System {
                                let (light, dark) = (
                                    theme_registry.get(LIGHT_THEMES[index]).unwrap(),
                                    theme_registry.get(DARK_THEMES[index]).unwrap(),
                                );
                                this.child(
                                    ThemePreviewTile::new(light, theme_seed)
                                        .style(ThemePreviewStyle::SideBySide(dark)),
                                )
                            } else {
                                this.child(
                                    ThemePreviewTile::new(theme.clone(), theme_seed)
                                        .style(ThemePreviewStyle::Bordered),
                                )
                            }
                        }),
                )
                .child(
                    Label::new(FAMILY_NAMES[index].clone())
                        .color(Color::Muted)
                        .size(LabelSize::Small),
                )
        })
    }

    fn write_mode_change(mode: ThemeMode, cx: &mut App) {
        let fs = <dyn Fs>::global(cx);
        update_settings_file::<ThemeSettings>(fs, cx, move |settings, _cx| {
            settings.set_mode(mode);
        });
    }

    fn write_theme_change(theme: impl Into<Arc<str>>, theme_mode: ThemeMode, cx: &mut App) {
        let fs = <dyn Fs>::global(cx);
        let theme = theme.into();
        update_settings_file::<ThemeSettings>(fs, cx, move |settings, cx| {
            if theme_mode == ThemeMode::System {
                let (light_theme, dark_theme) =
                    get_theme_family_themes(&theme).unwrap_or((theme.as_ref(), theme.as_ref()));

                settings.theme = Some(ThemeSelection::Dynamic {
                    mode: ThemeMode::System,
                    light: ThemeName(light_theme.into()),
                    dark: ThemeName(dark_theme.into()),
                });
            } else {
                let appearance = *SystemAppearance::global(cx);
                settings.set_theme(theme, appearance);
            }
        });
    }
}

fn render_telemetry_section(tab_index: &mut isize, cx: &App) -> impl IntoElement {
    let fs = <dyn Fs>::global(cx);

    v_flex()
        .pt_6()
        .gap_4()
        .border_t_1()
        .border_color(cx.theme().colors().border_variant.opacity(0.5))
        .child(Label::new("Telemetry").size(LabelSize::Large))
        .child(SwitchField::new(
            "onboarding-telemetry-metrics",
            "Help Improve Zed",
            Some("Anonymous usage data helps us build the right features and improve your experience.".into()),
            if TelemetrySettings::get_global(cx).metrics {
                ui::ToggleState::Selected
            } else {
                ui::ToggleState::Unselected
            },
            {
            let fs = fs.clone();
            move |selection, _, cx| {
                let enabled = match selection {
                    ToggleState::Selected => true,
                    ToggleState::Unselected => false,
                    ToggleState::Indeterminate => { return; },
                };

                update_settings_file::<TelemetrySettings>(
                    fs.clone(),
                    cx,
                    move |setting, _| setting.metrics = Some(enabled),
                );
            }},
        ).tab_index({
            *tab_index += 1;
            *tab_index
        }))
        .child(SwitchField::new(
            "onboarding-telemetry-crash-reports",
            "Help Fix Zed",
            Some("Send crash reports so we can fix critical issues fast.".into()),
            if TelemetrySettings::get_global(cx).diagnostics {
                ui::ToggleState::Selected
            } else {
                ui::ToggleState::Unselected
            },
            {
                let fs = fs.clone();
                move |selection, _, cx| {
                    let enabled = match selection {
                        ToggleState::Selected => true,
                        ToggleState::Unselected => false,
                        ToggleState::Indeterminate => { return; },
                    };

                    update_settings_file::<TelemetrySettings>(
                        fs.clone(),
                        cx,
                        move |setting, _| setting.diagnostics = Some(enabled),
                    );
                }
            }
        ).tab_index({
                    *tab_index += 1;
                    *tab_index
                }))
}

fn render_base_keymap_section(tab_index: &mut isize, cx: &mut App) -> impl IntoElement {
    let base_keymap = match BaseKeymap::get_global(cx) {
        BaseKeymap::VSCode => Some(0),
        BaseKeymap::JetBrains => Some(1),
        BaseKeymap::SublimeText => Some(2),
        BaseKeymap::Atom => Some(3),
        BaseKeymap::Emacs => Some(4),
        BaseKeymap::Cursor => Some(5),
        BaseKeymap::TextMate | BaseKeymap::None => None,
    };

    return v_flex().gap_2().child(Label::new("Base Keymap")).child(
        ToggleButtonGroup::two_rows(
            "base_keymap_selection",
            [
                ToggleButtonWithIcon::new("VS Code", IconName::EditorVsCode, |_, _, cx| {
                    write_keymap_base(BaseKeymap::VSCode, cx);
                }),
                ToggleButtonWithIcon::new("Jetbrains", IconName::EditorJetBrains, |_, _, cx| {
                    write_keymap_base(BaseKeymap::JetBrains, cx);
                }),
                ToggleButtonWithIcon::new("Sublime Text", IconName::EditorSublime, |_, _, cx| {
                    write_keymap_base(BaseKeymap::SublimeText, cx);
                }),
            ],
            [
                ToggleButtonWithIcon::new("Atom", IconName::EditorAtom, |_, _, cx| {
                    write_keymap_base(BaseKeymap::Atom, cx);
                }),
                ToggleButtonWithIcon::new("Emacs", IconName::EditorEmacs, |_, _, cx| {
                    write_keymap_base(BaseKeymap::Emacs, cx);
                }),
                ToggleButtonWithIcon::new("Cursor", IconName::EditorCursor, |_, _, cx| {
                    write_keymap_base(BaseKeymap::Cursor, cx);
                }),
            ],
        )
        .when_some(base_keymap, |this, base_keymap| {
            this.selected_index(base_keymap)
        })
        .full_width()
        .tab_index(tab_index)
        .size(ui::ToggleButtonGroupSize::Medium)
        .style(ui::ToggleButtonGroupStyle::Outlined),
    );

    fn write_keymap_base(keymap_base: BaseKeymap, cx: &App) {
        let fs = <dyn Fs>::global(cx);

        update_settings_file::<BaseKeymap>(fs, cx, move |setting, _| {
            *setting = Some(keymap_base);
        });
    }
}

fn render_vim_mode_switch(tab_index: &mut isize, cx: &mut App) -> impl IntoElement {
    let editor_mode = EditorModeSetting::get_global(cx).0;
    let toggle_state = if editor_mode.is_modal() {
        ui::ToggleState::Selected
    } else {
        ui::ToggleState::Unselected
    };

    SwitchField::new(
        "onboarding-vim-mode",
        "Vim Mode",
        Some("Coming from Neovim? Use our first-class implementation of Vim Mode.".into()),
        toggle_state,
        {
            let fs = <dyn Fs>::global(cx);
            move |&selection, _, cx| {
                update_settings_file::<EditorModeSetting>(fs.clone(), cx, move |setting, _| {
                    *setting = match selection {
                        ToggleState::Selected => Some(EditorMode::vim()),
                        ToggleState::Unselected => Some(EditorMode::Default),
                        ToggleState::Indeterminate => None,
                    }
                });
            }
        },
    )
    .tab_index({
        *tab_index += 1;
        *tab_index - 1
    })
}

pub(crate) fn render_basics_page(cx: &mut App) -> impl IntoElement {
    let mut tab_index = 0;
    v_flex()
        .gap_6()
        .child(render_theme_section(&mut tab_index, cx))
        .child(render_base_keymap_section(&mut tab_index, cx))
        .child(render_vim_mode_switch(&mut tab_index, cx))
        .child(render_telemetry_section(&mut tab_index, cx))
}