use std::{ops::Range, path::PathBuf, sync::Arc};

use crate::{Buffer, LanguageToolchainStore, Location, Runnable};

use anyhow::Result;
use collections::HashMap;
use fs::Fs;
use gpui::{App, Entity, Task};
use lsp::LanguageServerName;
use task::{TaskTemplates, TaskVariables};
use text::BufferId;

pub struct RunnableRange {
    pub buffer_id: BufferId,
    pub run_range: Range<usize>,
    pub full_range: Range<usize>,
    pub runnable: Runnable,
    pub extra_captures: HashMap<String, String>,
}

/// Language Contexts are used by Zed tasks to extract information about the source file where the tasks are supposed to be scheduled from.
/// Multiple context providers may be used together: by default, Zed provides a base [`BasicContextProvider`] context that fills all non-custom [`VariableName`] variants.
///
/// The context will be used to fill data for the tasks, and filter out the ones that do not have the variables required.
pub trait ContextProvider: Send + Sync {
    /// Builds a specific context to be placed on top of the basic one (replacing all conflicting entries) and to be used for task resolving later.
    fn build_context(
        &self,
        _variables: &TaskVariables,
        _location: ContextLocation<'_>,
        _project_env: Option<HashMap<String, String>>,
        _toolchains: Arc<dyn LanguageToolchainStore>,
        _cx: &mut App,
    ) -> Task<Result<TaskVariables>> {
        let _ = _location;
        Task::ready(Ok(TaskVariables::default()))
    }

    /// Provides all tasks, associated with the current language.
    fn associated_tasks(&self, _: Option<Entity<Buffer>>, _: &App) -> Task<Option<TaskTemplates>> {
        Task::ready(None)
    }

    /// A language server name, that can return tasks using LSP (ext) for this language.
    fn lsp_task_source(&self) -> Option<LanguageServerName> {
        None
    }
}

/// Metadata about the place in the project we gather the context for.
pub struct ContextLocation<'a> {
    pub fs: Option<Arc<dyn Fs>>,
    pub worktree_root: Option<PathBuf>,
    pub file_location: &'a Location,
}
