use std::sync::Arc;

use ::settings::Settings;
use editor::{tasks::task_context, Editor};
use gpui::{AppContext, ViewContext, WindowContext};
use language::Language;
use modal::TasksModal;
use project::WorktreeId;
use workspace::tasks::schedule_task;
use workspace::{tasks::schedule_resolved_task, Workspace};

mod modal;
mod settings;

pub use modal::Spawn;

pub fn init(cx: &mut AppContext) {
    settings::TaskSettings::register(cx);
    cx.observe_new_views(
        |workspace: &mut Workspace, _: &mut ViewContext<Workspace>| {
            workspace
                .register_action(spawn_task_or_modal)
                .register_action(move |workspace, action: &modal::Rerun, cx| {
                    if let Some((task_source_kind, mut last_scheduled_task)) =
                        workspace.project().update(cx, |project, cx| {
                            project.task_inventory().read(cx).last_scheduled_task()
                        })
                    {
                        if action.reevaluate_context {
                            let mut original_task = last_scheduled_task.original_task().clone();
                            if let Some(allow_concurrent_runs) = action.allow_concurrent_runs {
                                original_task.allow_concurrent_runs = allow_concurrent_runs;
                            }
                            if let Some(use_new_terminal) = action.use_new_terminal {
                                original_task.use_new_terminal = use_new_terminal;
                            }
                            let task_context = task_context(workspace, cx);
                            schedule_task(
                                workspace,
                                task_source_kind,
                                &original_task,
                                &task_context,
                                false,
                                cx,
                            )
                        } else {
                            if let Some(resolved) = last_scheduled_task.resolved.as_mut() {
                                if let Some(allow_concurrent_runs) = action.allow_concurrent_runs {
                                    resolved.allow_concurrent_runs = allow_concurrent_runs;
                                }
                                if let Some(use_new_terminal) = action.use_new_terminal {
                                    resolved.use_new_terminal = use_new_terminal;
                                }
                            }

                            schedule_resolved_task(
                                workspace,
                                task_source_kind,
                                last_scheduled_task,
                                false,
                                cx,
                            );
                        }
                    } else {
                        toggle_modal(workspace, cx);
                    };
                });
        },
    )
    .detach();
}

fn spawn_task_or_modal(workspace: &mut Workspace, action: &Spawn, cx: &mut ViewContext<Workspace>) {
    match &action.task_name {
        Some(name) => spawn_task_with_name(name.clone(), cx),
        None => toggle_modal(workspace, cx),
    }
}

fn toggle_modal(workspace: &mut Workspace, cx: &mut ViewContext<'_, Workspace>) {
    let inventory = workspace.project().read(cx).task_inventory().clone();
    let workspace_handle = workspace.weak_handle();
    let task_context = task_context(workspace, cx);
    workspace.toggle_modal(cx, |cx| {
        TasksModal::new(inventory, task_context, workspace_handle, cx)
    })
}

fn spawn_task_with_name(name: String, cx: &mut ViewContext<Workspace>) {
    cx.spawn(|workspace, mut cx| async move {
        let did_spawn = workspace
            .update(&mut cx, |workspace, cx| {
                let (worktree, language) = active_item_selection_properties(workspace, cx);
                let tasks = workspace.project().update(cx, |project, cx| {
                    project
                        .task_inventory()
                        .update(cx, |inventory, _| inventory.list_tasks(language, worktree))
                });
                let (task_source_kind, target_task) =
                    tasks.into_iter().find(|(_, task)| task.label == name)?;
                let task_context = task_context(workspace, cx);
                schedule_task(
                    workspace,
                    task_source_kind,
                    &target_task,
                    &task_context,
                    false,
                    cx,
                );
                Some(())
            })
            .ok()
            .flatten()
            .is_some();
        if !did_spawn {
            workspace
                .update(&mut cx, |workspace, cx| {
                    spawn_task_or_modal(workspace, &Spawn::default(), cx);
                })
                .ok();
        }
    })
    .detach();
}

fn active_item_selection_properties(
    workspace: &Workspace,
    cx: &mut WindowContext,
) -> (Option<WorktreeId>, Option<Arc<Language>>) {
    let active_item = workspace.active_item(cx);
    let worktree_id = active_item
        .as_ref()
        .and_then(|item| item.project_path(cx))
        .map(|path| path.worktree_id);
    let language = active_item
        .and_then(|active_item| active_item.act_as::<Editor>(cx))
        .and_then(|editor| {
            editor.update(cx, |editor, cx| {
                let selection = editor.selections.newest::<usize>(cx);
                let (buffer, buffer_position, _) = editor
                    .buffer()
                    .read(cx)
                    .point_to_buffer_offset(selection.start, cx)?;
                buffer.read(cx).language_at(buffer_position)
            })
        });
    (worktree_id, language)
}

#[cfg(test)]
mod tests {
    use std::sync::Arc;

    use editor::Editor;
    use gpui::{Entity, TestAppContext};
    use language::{BasicContextProvider, Language, LanguageConfig};
    use project::{FakeFs, Project};
    use serde_json::json;
    use task::{TaskContext, TaskVariables, VariableName};
    use ui::VisualContext;
    use workspace::{AppState, Workspace};

    use crate::task_context;

    #[gpui::test]
    async fn test_default_language_context(cx: &mut TestAppContext) {
        init_test(cx);
        let fs = FakeFs::new(cx.executor());
        fs.insert_tree(
            "/dir",
            json!({
                ".zed": {
                    "tasks.json": r#"[
                            {
                                "label": "example task",
                                "command": "echo",
                                "args": ["4"]
                            },
                            {
                                "label": "another one",
                                "command": "echo",
                                "args": ["55"]
                            },
                        ]"#,
                },
                "a.ts": "function this_is_a_test() { }",
                "rust": {
                                    "b.rs": "use std; fn this_is_a_rust_file() { }",
                }

            }),
        )
        .await;

        let rust_language = Arc::new(
            Language::new(
                LanguageConfig::default(),
                Some(tree_sitter_rust::language()),
            )
            .with_outline_query(
                r#"(function_item
            "fn" @context
            name: (_) @name) @item"#,
            )
            .unwrap()
            .with_context_provider(Some(Arc::new(BasicContextProvider))),
        );

        let typescript_language = Arc::new(
            Language::new(
                LanguageConfig::default(),
                Some(tree_sitter_typescript::language_typescript()),
            )
            .with_outline_query(
                r#"(function_declaration
                    "async"? @context
                    "function" @context
                    name: (_) @name
                    parameters: (formal_parameters
                      "(" @context
                      ")" @context)) @item"#,
            )
            .unwrap()
            .with_context_provider(Some(Arc::new(BasicContextProvider))),
        );
        let project = Project::test(fs, ["/dir".as_ref()], cx).await;
        let worktree_id = project.update(cx, |project, cx| {
            project.worktrees().next().unwrap().read(cx).id()
        });
        let (workspace, cx) = cx.add_window_view(|cx| Workspace::test_new(project.clone(), cx));

        let buffer1 = workspace
            .update(cx, |this, cx| {
                this.project()
                    .update(cx, |this, cx| this.open_buffer((worktree_id, "a.ts"), cx))
            })
            .await
            .unwrap();
        buffer1.update(cx, |this, cx| {
            this.set_language(Some(typescript_language), cx)
        });
        let editor1 = cx.new_view(|cx| Editor::for_buffer(buffer1, Some(project.clone()), cx));
        let buffer2 = workspace
            .update(cx, |this, cx| {
                this.project().update(cx, |this, cx| {
                    this.open_buffer((worktree_id, "rust/b.rs"), cx)
                })
            })
            .await
            .unwrap();
        buffer2.update(cx, |this, cx| this.set_language(Some(rust_language), cx));
        let editor2 = cx.new_view(|cx| Editor::for_buffer(buffer2, Some(project), cx));
        workspace.update(cx, |this, cx| {
            this.add_item_to_center(Box::new(editor1.clone()), cx);
            this.add_item_to_center(Box::new(editor2.clone()), cx);
            assert_eq!(this.active_item(cx).unwrap().item_id(), editor2.entity_id());
            assert_eq!(
                task_context(this, cx),
                TaskContext {
                    cwd: Some("/dir".into()),
                    task_variables: TaskVariables::from_iter([
                        (VariableName::File, "/dir/rust/b.rs".into()),
                        (VariableName::WorktreeRoot, "/dir".into()),
                        (VariableName::Row, "1".into()),
                        (VariableName::Column, "1".into()),
                    ])
                }
            );
            // And now, let's select an identifier.
            editor2.update(cx, |this, cx| {
                this.change_selections(None, cx, |selections| selections.select_ranges([14..18]))
            });
            assert_eq!(
                task_context(this, cx),
                TaskContext {
                    cwd: Some("/dir".into()),
                    task_variables: TaskVariables::from_iter([
                        (VariableName::File, "/dir/rust/b.rs".into()),
                        (VariableName::WorktreeRoot, "/dir".into()),
                        (VariableName::Row, "1".into()),
                        (VariableName::Column, "15".into()),
                        (VariableName::SelectedText, "is_i".into()),
                        (VariableName::Symbol, "this_is_a_rust_file".into()),
                    ])
                }
            );

            // Now, let's switch the active item to .ts file.
            this.activate_item(&editor1, cx);
            assert_eq!(
                task_context(this, cx),
                TaskContext {
                    cwd: Some("/dir".into()),
                    task_variables: TaskVariables::from_iter([
                        (VariableName::File, "/dir/a.ts".into()),
                        (VariableName::WorktreeRoot, "/dir".into()),
                        (VariableName::Row, "1".into()),
                        (VariableName::Column, "1".into()),
                        (VariableName::Symbol, "this_is_a_test".into()),
                    ])
                }
            );
        });
    }

    pub(crate) fn init_test(cx: &mut TestAppContext) -> Arc<AppState> {
        cx.update(|cx| {
            let state = AppState::test(cx);
            file_icons::init((), cx);
            language::init(cx);
            crate::init(cx);
            editor::init(cx);
            workspace::init_settings(cx);
            Project::init_settings(cx);
            state
        })
    }
}