use crate::branch_picker::{self, BranchList};
use crate::git_panel::{GitPanel, commit_message_editor};
use git::repository::CommitOptions;
use git::{Amend, Commit, GenerateCommitMessage};
use panel::{panel_button, panel_editor_style, panel_filled_button};
use ui::{
    ContextMenu, KeybindingHint, PopoverMenu, PopoverMenuHandle, SplitButton, Tooltip, prelude::*,
};

use editor::{Editor, EditorElement};
use gpui::*;
use util::ResultExt;
use workspace::{
    ModalView, Workspace,
    dock::{Dock, PanelHandle},
};

// nate: It is a pain to get editors to size correctly and not overflow.
//
// this can get replaced with a simple flex layout with more time/a more thoughtful approach.
#[derive(Debug, Clone, Copy)]
pub struct ModalContainerProperties {
    pub modal_width: f32,
    pub editor_height: f32,
    pub footer_height: f32,
    pub container_padding: f32,
    pub modal_border_radius: f32,
}

impl ModalContainerProperties {
    pub fn new(window: &Window, preferred_char_width: usize) -> Self {
        let container_padding = 5.0;

        // Calculate width based on character width
        let mut modal_width = 460.0;
        let style = window.text_style().clone();
        let font_id = window.text_system().resolve_font(&style.font());
        let font_size = style.font_size.to_pixels(window.rem_size());

        if let Ok(em_width) = window.text_system().em_width(font_id, font_size) {
            modal_width = preferred_char_width as f32 * em_width.0 + (container_padding * 2.0);
        }

        Self {
            modal_width,
            editor_height: 300.0,
            footer_height: 24.0,
            container_padding,
            modal_border_radius: 12.0,
        }
    }

    pub fn editor_border_radius(&self) -> Pixels {
        px(self.modal_border_radius - self.container_padding / 2.0)
    }
}

pub struct CommitModal {
    git_panel: Entity<GitPanel>,
    commit_editor: Entity<Editor>,
    restore_dock: RestoreDock,
    properties: ModalContainerProperties,
    branch_list_handle: PopoverMenuHandle<BranchList>,
    commit_menu_handle: PopoverMenuHandle<ContextMenu>,
}

impl Focusable for CommitModal {
    fn focus_handle(&self, cx: &App) -> gpui::FocusHandle {
        self.commit_editor.focus_handle(cx)
    }
}

impl EventEmitter<DismissEvent> for CommitModal {}
impl ModalView for CommitModal {
    fn on_before_dismiss(
        &mut self,
        window: &mut Window,
        cx: &mut Context<Self>,
    ) -> workspace::DismissDecision {
        self.git_panel.update(cx, |git_panel, cx| {
            git_panel.set_modal_open(false, cx);
        });
        self.restore_dock
            .dock
            .update(cx, |dock, cx| {
                if let Some(active_index) = self.restore_dock.active_index {
                    dock.activate_panel(active_index, window, cx)
                }
                dock.set_open(self.restore_dock.is_open, window, cx)
            })
            .log_err();
        workspace::DismissDecision::Dismiss(true)
    }
}

struct RestoreDock {
    dock: WeakEntity<Dock>,
    is_open: bool,
    active_index: Option<usize>,
}

pub enum ForceMode {
    Amend,
    Commit,
}

impl CommitModal {
    pub fn register(workspace: &mut Workspace) {
        workspace.register_action(|workspace, _: &Commit, window, cx| {
            CommitModal::toggle(workspace, Some(ForceMode::Commit), window, cx);
        });
        workspace.register_action(|workspace, _: &Amend, window, cx| {
            CommitModal::toggle(workspace, Some(ForceMode::Amend), window, cx);
        });
    }

    pub fn toggle(
        workspace: &mut Workspace,
        force_mode: Option<ForceMode>,
        window: &mut Window,
        cx: &mut Context<Workspace>,
    ) {
        let Some(git_panel) = workspace.panel::<GitPanel>(cx) else {
            return;
        };

        git_panel.update(cx, |git_panel, cx| {
            if let Some(force_mode) = force_mode {
                match force_mode {
                    ForceMode::Amend => {
                        if git_panel
                            .active_repository
                            .as_ref()
                            .and_then(|repo| repo.read(cx).head_commit.as_ref())
                            .is_some()
                        {
                            if !git_panel.amend_pending() {
                                git_panel.set_amend_pending(true, cx);
                                git_panel.load_last_commit_message_if_empty(cx);
                            }
                        }
                    }
                    ForceMode::Commit => {
                        if git_panel.amend_pending() {
                            git_panel.set_amend_pending(false, cx);
                        }
                    }
                }
            }
            git_panel.set_modal_open(true, cx);
        });

        let dock = workspace.dock_at_position(git_panel.position(window, cx));
        let is_open = dock.read(cx).is_open();
        let active_index = dock.read(cx).active_panel_index();
        let dock = dock.downgrade();
        let restore_dock_position = RestoreDock {
            dock,
            is_open,
            active_index,
        };

        workspace.open_panel::<GitPanel>(window, cx);
        workspace.toggle_modal(window, cx, move |window, cx| {
            CommitModal::new(git_panel, restore_dock_position, window, cx)
        })
    }

    fn new(
        git_panel: Entity<GitPanel>,
        restore_dock: RestoreDock,
        window: &mut Window,
        cx: &mut Context<Self>,
    ) -> Self {
        let panel = git_panel.read(cx);
        let suggested_commit_message = panel.suggest_commit_message(cx);

        let commit_editor = git_panel.update(cx, |git_panel, cx| {
            git_panel.set_modal_open(true, cx);
            let buffer = git_panel.commit_message_buffer(cx).clone();
            let panel_editor = git_panel.commit_editor.clone();
            let project = git_panel.project.clone();

            cx.new(|cx| {
                let mut editor =
                    commit_message_editor(buffer, None, project.clone(), false, window, cx);
                editor.sync_selections(panel_editor, cx).detach();

                editor
            })
        });

        let commit_message = commit_editor.read(cx).text(cx);

        if let Some(suggested_commit_message) = suggested_commit_message {
            if commit_message.is_empty() {
                commit_editor.update(cx, |editor, cx| {
                    editor.set_placeholder_text(suggested_commit_message, cx);
                });
            }
        }

        let focus_handle = commit_editor.focus_handle(cx);

        cx.on_focus_out(&focus_handle, window, |this, _, window, cx| {
            if !this.branch_list_handle.is_focused(window, cx)
                && !this.commit_menu_handle.is_focused(window, cx)
            {
                cx.emit(DismissEvent);
            }
        })
        .detach();

        let properties = ModalContainerProperties::new(window, 50);

        Self {
            git_panel,
            commit_editor,
            restore_dock,
            properties,
            branch_list_handle: PopoverMenuHandle::default(),
            commit_menu_handle: PopoverMenuHandle::default(),
        }
    }

    fn commit_editor_element(&self, window: &mut Window, cx: &mut Context<Self>) -> EditorElement {
        let editor_style = panel_editor_style(true, window, cx);
        EditorElement::new(&self.commit_editor, editor_style)
    }

    pub fn render_commit_editor(
        &self,
        window: &mut Window,
        cx: &mut Context<Self>,
    ) -> impl IntoElement {
        let properties = self.properties;
        let padding_t = 3.0;
        let padding_b = 6.0;
        // magic number for editor not to overflow the container??
        let extra_space_hack = 1.5 * window.line_height();

        v_flex()
            .h(px(properties.editor_height + padding_b + padding_t) + extra_space_hack)
            .w_full()
            .flex_none()
            .rounded(properties.editor_border_radius())
            .overflow_hidden()
            .px_1p5()
            .pt(px(padding_t))
            .pb(px(padding_b))
            .child(
                div()
                    .h(px(properties.editor_height))
                    .w_full()
                    .child(self.commit_editor_element(window, cx)),
            )
    }

    fn render_git_commit_menu(
        &self,
        id: impl Into<ElementId>,
        keybinding_target: Option<FocusHandle>,
    ) -> impl IntoElement {
        PopoverMenu::new(id.into())
            .trigger(
                ui::ButtonLike::new_rounded_right("commit-split-button-right")
                    .layer(ui::ElevationIndex::ModalSurface)
                    .size(ui::ButtonSize::None)
                    .child(
                        div()
                            .px_1()
                            .child(Icon::new(IconName::ChevronDownSmall).size(IconSize::XSmall)),
                    ),
            )
            .menu(move |window, cx| {
                Some(ContextMenu::build(window, cx, |context_menu, _, _| {
                    context_menu
                        .when_some(keybinding_target.clone(), |el, keybinding_target| {
                            el.context(keybinding_target.clone())
                        })
                        .action("Amend", Amend.boxed_clone())
                }))
            })
            .with_handle(self.commit_menu_handle.clone())
            .anchor(Corner::TopRight)
    }

    pub fn render_footer(&self, window: &mut Window, cx: &mut Context<Self>) -> impl IntoElement {
        let (
            can_commit,
            tooltip,
            commit_label,
            co_authors,
            generate_commit_message,
            active_repo,
            is_amend_pending,
            has_previous_commit,
        ) = self.git_panel.update(cx, |git_panel, cx| {
            let (can_commit, tooltip) = git_panel.configure_commit_button(cx);
            let title = git_panel.commit_button_title();
            let co_authors = git_panel.render_co_authors(cx);
            let generate_commit_message = git_panel.render_generate_commit_message_button(cx);
            let active_repo = git_panel.active_repository.clone();
            let is_amend_pending = git_panel.amend_pending();
            let has_previous_commit = active_repo
                .as_ref()
                .and_then(|repo| repo.read(cx).head_commit.as_ref())
                .is_some();
            (
                can_commit,
                tooltip,
                title,
                co_authors,
                generate_commit_message,
                active_repo,
                is_amend_pending,
                has_previous_commit,
            )
        });

        let branch = active_repo
            .as_ref()
            .and_then(|repo| repo.read(cx).branch.as_ref())
            .map(|b| b.name().to_owned())
            .unwrap_or_else(|| "<no branch>".to_owned());

        let branch_picker_button = panel_button(branch)
            .icon(IconName::GitBranch)
            .icon_size(IconSize::Small)
            .icon_color(Color::Placeholder)
            .color(Color::Muted)
            .icon_position(IconPosition::Start)
            .tooltip(Tooltip::for_action_title(
                "Switch Branch",
                &zed_actions::git::Branch,
            ))
            .on_click(cx.listener(|_, _, window, cx| {
                window.dispatch_action(zed_actions::git::Branch.boxed_clone(), cx);
            }))
            .style(ButtonStyle::Transparent);

        let branch_picker = PopoverMenu::new("popover-button")
            .menu(move |window, cx| Some(branch_picker::popover(active_repo.clone(), window, cx)))
            .with_handle(self.branch_list_handle.clone())
            .trigger_with_tooltip(
                branch_picker_button,
                Tooltip::for_action_title("Switch Branch", &zed_actions::git::Branch),
            )
            .anchor(Corner::BottomLeft)
            .offset(gpui::Point {
                x: px(0.0),
                y: px(-2.0),
            });
        let focus_handle = self.focus_handle(cx);

        let close_kb_hint =
            if let Some(close_kb) = ui::KeyBinding::for_action(&menu::Cancel, window, cx) {
                Some(
                    KeybindingHint::new(close_kb, cx.theme().colors().editor_background)
                        .suffix("Cancel"),
                )
            } else {
                None
            };

        h_flex()
            .group("commit_editor_footer")
            .flex_none()
            .w_full()
            .items_center()
            .justify_between()
            .w_full()
            .h(px(self.properties.footer_height))
            .gap_1()
            .child(
                h_flex()
                    .gap_1()
                    .flex_shrink()
                    .overflow_x_hidden()
                    .child(
                        h_flex()
                            .flex_shrink()
                            .overflow_x_hidden()
                            .child(branch_picker),
                    )
                    .children(generate_commit_message)
                    .children(co_authors),
            )
            .child(div().flex_1())
            .child(
                h_flex()
                    .items_center()
                    .justify_end()
                    .flex_none()
                    .px_1()
                    .gap_4()
                    .children(close_kb_hint)
                    .when(is_amend_pending, |this| {
                        let focus_handle = focus_handle.clone();
                        this.child(
                            panel_filled_button(commit_label)
                                .tooltip(move |window, cx| {
                                    if can_commit {
                                        Tooltip::for_action_in(
                                            tooltip,
                                            &Amend,
                                            &focus_handle,
                                            window,
                                            cx,
                                        )
                                    } else {
                                        Tooltip::simple(tooltip, cx)
                                    }
                                })
                                .disabled(!can_commit)
                                .on_click(cx.listener(move |this, _: &ClickEvent, window, cx| {
                                    telemetry::event!("Git Amended", source = "Git Modal");
                                    this.git_panel.update(cx, |git_panel, cx| {
                                        git_panel.set_amend_pending(false, cx);
                                        git_panel.commit_changes(
                                            CommitOptions { amend: true },
                                            window,
                                            cx,
                                        );
                                    });
                                    cx.emit(DismissEvent);
                                })),
                        )
                    })
                    .when(!is_amend_pending, |this| {
                        this.when(has_previous_commit, |this| {
                            this.child(SplitButton::new(
                                ui::ButtonLike::new_rounded_left(ElementId::Name(
                                    format!("split-button-left-{}", commit_label).into(),
                                ))
                                .layer(ui::ElevationIndex::ModalSurface)
                                .size(ui::ButtonSize::Compact)
                                .child(
                                    div()
                                        .child(Label::new(commit_label).size(LabelSize::Small))
                                        .mr_0p5(),
                                )
                                .on_click(cx.listener(move |this, _: &ClickEvent, window, cx| {
                                    telemetry::event!("Git Committed", source = "Git Modal");
                                    this.git_panel.update(cx, |git_panel, cx| {
                                        git_panel.commit_changes(
                                            CommitOptions { amend: false },
                                            window,
                                            cx,
                                        )
                                    });
                                    cx.emit(DismissEvent);
                                }))
                                .disabled(!can_commit)
                                .tooltip({
                                    let focus_handle = focus_handle.clone();
                                    move |window, cx| {
                                        if can_commit {
                                            Tooltip::with_meta_in(
                                                tooltip,
                                                Some(&git::Commit),
                                                "git commit",
                                                &focus_handle.clone(),
                                                window,
                                                cx,
                                            )
                                        } else {
                                            Tooltip::simple(tooltip, cx)
                                        }
                                    }
                                }),
                                self.render_git_commit_menu(
                                    ElementId::Name(
                                        format!("split-button-right-{}", commit_label).into(),
                                    ),
                                    Some(focus_handle.clone()),
                                )
                                .into_any_element(),
                            ))
                        })
                        .when(!has_previous_commit, |this| {
                            this.child(
                                panel_filled_button(commit_label)
                                    .tooltip(move |window, cx| {
                                        if can_commit {
                                            Tooltip::with_meta_in(
                                                tooltip,
                                                Some(&git::Commit),
                                                "git commit",
                                                &focus_handle,
                                                window,
                                                cx,
                                            )
                                        } else {
                                            Tooltip::simple(tooltip, cx)
                                        }
                                    })
                                    .disabled(!can_commit)
                                    .on_click(cx.listener(
                                        move |this, _: &ClickEvent, window, cx| {
                                            telemetry::event!(
                                                "Git Committed",
                                                source = "Git Modal"
                                            );
                                            this.git_panel.update(cx, |git_panel, cx| {
                                                git_panel.commit_changes(
                                                    CommitOptions { amend: false },
                                                    window,
                                                    cx,
                                                )
                                            });
                                            cx.emit(DismissEvent);
                                        },
                                    )),
                            )
                        })
                    }),
            )
    }

    fn dismiss(&mut self, _: &menu::Cancel, _: &mut Window, cx: &mut Context<Self>) {
        if self.git_panel.read(cx).amend_pending() {
            self.git_panel
                .update(cx, |git_panel, cx| git_panel.set_amend_pending(false, cx));
        } else {
            cx.emit(DismissEvent);
        }
    }

    fn commit(&mut self, _: &git::Commit, window: &mut Window, cx: &mut Context<Self>) {
        if self.git_panel.read(cx).amend_pending() {
            return;
        }
        telemetry::event!("Git Committed", source = "Git Modal");
        self.git_panel.update(cx, |git_panel, cx| {
            git_panel.commit_changes(CommitOptions { amend: false }, window, cx)
        });
        cx.emit(DismissEvent);
    }

    fn amend(&mut self, _: &git::Amend, window: &mut Window, cx: &mut Context<Self>) {
        if self
            .git_panel
            .read(cx)
            .active_repository
            .as_ref()
            .and_then(|repo| repo.read(cx).head_commit.as_ref())
            .is_none()
        {
            return;
        }
        if !self.git_panel.read(cx).amend_pending() {
            self.git_panel.update(cx, |git_panel, cx| {
                git_panel.set_amend_pending(true, cx);
                git_panel.load_last_commit_message_if_empty(cx);
            });
        } else {
            telemetry::event!("Git Amended", source = "Git Modal");
            self.git_panel.update(cx, |git_panel, cx| {
                git_panel.set_amend_pending(false, cx);
                git_panel.commit_changes(CommitOptions { amend: true }, window, cx);
            });
            cx.emit(DismissEvent);
        }
    }

    fn toggle_branch_selector(&mut self, window: &mut Window, cx: &mut Context<Self>) {
        if self.branch_list_handle.is_focused(window, cx) {
            self.focus_handle(cx).focus(window)
        } else {
            self.branch_list_handle.toggle(window, cx);
        }
    }
}

impl Render for CommitModal {
    fn render(&mut self, window: &mut Window, cx: &mut Context<Self>) -> impl IntoElement {
        let properties = self.properties;
        let width = px(properties.modal_width);
        let container_padding = px(properties.container_padding);
        let border_radius = properties.modal_border_radius;
        let editor_focus_handle = self.commit_editor.focus_handle(cx);

        v_flex()
            .id("commit-modal")
            .key_context("GitCommit")
            .on_action(cx.listener(Self::dismiss))
            .on_action(cx.listener(Self::commit))
            .on_action(cx.listener(Self::amend))
            .on_action(cx.listener(|this, _: &GenerateCommitMessage, _, cx| {
                this.git_panel.update(cx, |panel, cx| {
                    panel.generate_commit_message(cx);
                })
            }))
            .on_action(
                cx.listener(|this, _: &zed_actions::git::Branch, window, cx| {
                    this.toggle_branch_selector(window, cx);
                }),
            )
            .on_action(
                cx.listener(|this, _: &zed_actions::git::CheckoutBranch, window, cx| {
                    this.toggle_branch_selector(window, cx);
                }),
            )
            .on_action(
                cx.listener(|this, _: &zed_actions::git::Switch, window, cx| {
                    this.toggle_branch_selector(window, cx);
                }),
            )
            .elevation_3(cx)
            .overflow_hidden()
            .flex_none()
            .relative()
            .bg(cx.theme().colors().elevated_surface_background)
            .rounded(px(border_radius))
            .border_1()
            .border_color(cx.theme().colors().border)
            .w(width)
            .p(container_padding)
            .child(
                v_flex()
                    .id("editor-container")
                    .justify_between()
                    .p_2()
                    .size_full()
                    .gap_2()
                    .rounded(properties.editor_border_radius())
                    .overflow_hidden()
                    .cursor_text()
                    .bg(cx.theme().colors().editor_background)
                    .border_1()
                    .border_color(cx.theme().colors().border_variant)
                    .on_click(cx.listener(move |_, _: &ClickEvent, window, _cx| {
                        window.focus(&editor_focus_handle);
                    }))
                    .child(
                        div()
                            .flex_1()
                            .size_full()
                            .child(self.render_commit_editor(window, cx)),
                    )
                    .child(self.render_footer(window, cx)),
            )
    }
}