use crate::schema::json_schema_for;
use anyhow::{Result, anyhow};
use assistant_tool::{ActionLog, Tool, ToolResult};
use gpui::{AnyWindowHandle, App, Entity, Task};
use language_model::{LanguageModel, LanguageModelRequest, LanguageModelToolSchemaFormat};
use project::{Project, WorktreeSettings};
use schemars::JsonSchema;
use serde::{Deserialize, Serialize};
use settings::Settings;
use std::{fmt::Write, path::Path, sync::Arc};
use ui::IconName;
use util::markdown::MarkdownInlineCode;

#[derive(Debug, Serialize, Deserialize, JsonSchema)]
pub struct ListDirectoryToolInput {
    /// The fully-qualified path of the directory to list in the project.
    ///
    /// This path should never be absolute, and the first component
    /// of the path should always be a root directory in a project.
    ///
    /// <example>
    /// If the project has the following root directories:
    ///
    /// - directory1
    /// - directory2
    ///
    /// You can list the contents of `directory1` by using the path `directory1`.
    /// </example>
    ///
    /// <example>
    /// If the project has the following root directories:
    ///
    /// - foo
    /// - bar
    ///
    /// If you wanna list contents in the directory `foo/baz`, you should use the path `foo/baz`.
    /// </example>
    pub path: String,
}

pub struct ListDirectoryTool;

impl Tool for ListDirectoryTool {
    fn name(&self) -> String {
        "list_directory".into()
    }

    fn needs_confirmation(&self, _: &serde_json::Value, _: &App) -> bool {
        false
    }

    fn may_perform_edits(&self) -> bool {
        false
    }

    fn description(&self) -> String {
        include_str!("./list_directory_tool/description.md").into()
    }

    fn icon(&self) -> IconName {
        IconName::Folder
    }

    fn input_schema(&self, format: LanguageModelToolSchemaFormat) -> Result<serde_json::Value> {
        json_schema_for::<ListDirectoryToolInput>(format)
    }

    fn ui_text(&self, input: &serde_json::Value) -> String {
        match serde_json::from_value::<ListDirectoryToolInput>(input.clone()) {
            Ok(input) => {
                let path = MarkdownInlineCode(&input.path);
                format!("List the {path} directory's contents")
            }
            Err(_) => "List directory".to_string(),
        }
    }

    fn run(
        self: Arc<Self>,
        input: serde_json::Value,
        _request: Arc<LanguageModelRequest>,
        project: Entity<Project>,
        _action_log: Entity<ActionLog>,
        _model: Arc<dyn LanguageModel>,
        _window: Option<AnyWindowHandle>,
        cx: &mut App,
    ) -> ToolResult {
        let input = match serde_json::from_value::<ListDirectoryToolInput>(input) {
            Ok(input) => input,
            Err(err) => return Task::ready(Err(anyhow!(err))).into(),
        };

        // Sometimes models will return these even though we tell it to give a path and not a glob.
        // When this happens, just list the root worktree directories.
        if matches!(input.path.as_str(), "." | "" | "./" | "*") {
            let output = project
                .read(cx)
                .worktrees(cx)
                .filter_map(|worktree| {
                    worktree.read(cx).root_entry().and_then(|entry| {
                        if entry.is_dir() {
                            entry.path.to_str()
                        } else {
                            None
                        }
                    })
                })
                .collect::<Vec<_>>()
                .join("\n");

            return Task::ready(Ok(output.into())).into();
        }

        let Some(project_path) = project.read(cx).find_project_path(&input.path, cx) else {
            return Task::ready(Err(anyhow!("Path {} not found in project", input.path))).into();
        };
        let Some(worktree) = project
            .read(cx)
            .worktree_for_id(project_path.worktree_id, cx)
        else {
            return Task::ready(Err(anyhow!("Worktree not found"))).into();
        };

        // Check if the directory whose contents we're listing is itself excluded or private
        let global_settings = WorktreeSettings::get_global(cx);
        if global_settings.is_path_excluded(&project_path.path) {
            return Task::ready(Err(anyhow!(
                "Cannot list directory because its path matches the user's global `file_scan_exclusions` setting: {}",
                &input.path
            )))
            .into();
        }

        if global_settings.is_path_private(&project_path.path) {
            return Task::ready(Err(anyhow!(
                "Cannot list directory because its path matches the user's global `private_files` setting: {}",
                &input.path
            )))
            .into();
        }

        let worktree_settings = WorktreeSettings::get(Some((&project_path).into()), cx);
        if worktree_settings.is_path_excluded(&project_path.path) {
            return Task::ready(Err(anyhow!(
                "Cannot list directory because its path matches the user's worktree`file_scan_exclusions` setting: {}",
                &input.path
            )))
            .into();
        }

        if worktree_settings.is_path_private(&project_path.path) {
            return Task::ready(Err(anyhow!(
                "Cannot list directory because its path matches the user's worktree `private_paths` setting: {}",
                &input.path
            )))
            .into();
        }

        let worktree_snapshot = worktree.read(cx).snapshot();
        let worktree_root_name = worktree.read(cx).root_name().to_string();

        let Some(entry) = worktree_snapshot.entry_for_path(&project_path.path) else {
            return Task::ready(Err(anyhow!("Path not found: {}", input.path))).into();
        };

        if !entry.is_dir() {
            return Task::ready(Err(anyhow!("{} is not a directory.", input.path))).into();
        }
        let worktree_snapshot = worktree.read(cx).snapshot();

        let mut folders = Vec::new();
        let mut files = Vec::new();

        for entry in worktree_snapshot.child_entries(&project_path.path) {
            // Skip private and excluded files and directories
            if global_settings.is_path_private(&entry.path)
                || global_settings.is_path_excluded(&entry.path)
            {
                continue;
            }

            if project
                .read(cx)
                .find_project_path(&entry.path, cx)
                .map(|project_path| {
                    let worktree_settings = WorktreeSettings::get(Some((&project_path).into()), cx);

                    worktree_settings.is_path_excluded(&project_path.path)
                        || worktree_settings.is_path_private(&project_path.path)
                })
                .unwrap_or(false)
            {
                continue;
            }

            let full_path = Path::new(&worktree_root_name)
                .join(&entry.path)
                .display()
                .to_string();
            if entry.is_dir() {
                folders.push(full_path);
            } else {
                files.push(full_path);
            }
        }

        let mut output = String::new();

        if !folders.is_empty() {
            writeln!(output, "# Folders:\n{}", folders.join("\n")).unwrap();
        }

        if !files.is_empty() {
            writeln!(output, "\n# Files:\n{}", files.join("\n")).unwrap();
        }

        if output.is_empty() {
            writeln!(output, "{} is empty.", input.path).unwrap();
        }

        Task::ready(Ok(output.into())).into()
    }
}

#[cfg(test)]
mod tests {
    use super::*;
    use assistant_tool::Tool;
    use gpui::{AppContext, TestAppContext, UpdateGlobal};
    use indoc::indoc;
    use language_model::fake_provider::FakeLanguageModel;
    use project::{FakeFs, Project, WorktreeSettings};
    use serde_json::json;
    use settings::SettingsStore;
    use util::path;

    fn platform_paths(path_str: &str) -> String {
        if cfg!(target_os = "windows") {
            path_str.replace("/", "\\")
        } else {
            path_str.to_string()
        }
    }

    fn init_test(cx: &mut TestAppContext) {
        cx.update(|cx| {
            let settings_store = SettingsStore::test(cx);
            cx.set_global(settings_store);
            language::init(cx);
            Project::init_settings(cx);
        });
    }

    #[gpui::test]
    async fn test_list_directory_separates_files_and_dirs(cx: &mut TestAppContext) {
        init_test(cx);

        let fs = FakeFs::new(cx.executor());
        fs.insert_tree(
            path!("/project"),
            json!({
                "src": {
                    "main.rs": "fn main() {}",
                    "lib.rs": "pub fn hello() {}",
                    "models": {
                        "user.rs": "struct User {}",
                        "post.rs": "struct Post {}"
                    },
                    "utils": {
                        "helper.rs": "pub fn help() {}"
                    }
                },
                "tests": {
                    "integration_test.rs": "#[test] fn test() {}"
                },
                "README.md": "# Project",
                "Cargo.toml": "[package]"
            }),
        )
        .await;

        let project = Project::test(fs.clone(), [path!("/project").as_ref()], cx).await;
        let action_log = cx.new(|_| ActionLog::new(project.clone()));
        let model = Arc::new(FakeLanguageModel::default());
        let tool = Arc::new(ListDirectoryTool);

        // Test listing root directory
        let input = json!({
            "path": "project"
        });

        let result = cx
            .update(|cx| {
                tool.clone().run(
                    input,
                    Arc::default(),
                    project.clone(),
                    action_log.clone(),
                    model.clone(),
                    None,
                    cx,
                )
            })
            .output
            .await
            .unwrap();

        let content = result.content.as_str().unwrap();
        assert_eq!(
            content,
            platform_paths(indoc! {"
                # Folders:
                project/src
                project/tests

                # Files:
                project/Cargo.toml
                project/README.md
            "})
        );

        // Test listing src directory
        let input = json!({
            "path": "project/src"
        });

        let result = cx
            .update(|cx| {
                tool.clone().run(
                    input,
                    Arc::default(),
                    project.clone(),
                    action_log.clone(),
                    model.clone(),
                    None,
                    cx,
                )
            })
            .output
            .await
            .unwrap();

        let content = result.content.as_str().unwrap();
        assert_eq!(
            content,
            platform_paths(indoc! {"
                # Folders:
                project/src/models
                project/src/utils

                # Files:
                project/src/lib.rs
                project/src/main.rs
            "})
        );

        // Test listing directory with only files
        let input = json!({
            "path": "project/tests"
        });

        let result = cx
            .update(|cx| {
                tool.clone().run(
                    input,
                    Arc::default(),
                    project.clone(),
                    action_log.clone(),
                    model.clone(),
                    None,
                    cx,
                )
            })
            .output
            .await
            .unwrap();

        let content = result.content.as_str().unwrap();
        assert!(!content.contains("# Folders:"));
        assert!(content.contains("# Files:"));
        assert!(content.contains(&platform_paths("project/tests/integration_test.rs")));
    }

    #[gpui::test]
    async fn test_list_directory_empty_directory(cx: &mut TestAppContext) {
        init_test(cx);

        let fs = FakeFs::new(cx.executor());
        fs.insert_tree(
            path!("/project"),
            json!({
                "empty_dir": {}
            }),
        )
        .await;

        let project = Project::test(fs.clone(), [path!("/project").as_ref()], cx).await;
        let action_log = cx.new(|_| ActionLog::new(project.clone()));
        let model = Arc::new(FakeLanguageModel::default());
        let tool = Arc::new(ListDirectoryTool);

        let input = json!({
            "path": "project/empty_dir"
        });

        let result = cx
            .update(|cx| tool.run(input, Arc::default(), project, action_log, model, None, cx))
            .output
            .await
            .unwrap();

        let content = result.content.as_str().unwrap();
        assert_eq!(content, "project/empty_dir is empty.\n");
    }

    #[gpui::test]
    async fn test_list_directory_error_cases(cx: &mut TestAppContext) {
        init_test(cx);

        let fs = FakeFs::new(cx.executor());
        fs.insert_tree(
            path!("/project"),
            json!({
                "file.txt": "content"
            }),
        )
        .await;

        let project = Project::test(fs.clone(), [path!("/project").as_ref()], cx).await;
        let action_log = cx.new(|_| ActionLog::new(project.clone()));
        let model = Arc::new(FakeLanguageModel::default());
        let tool = Arc::new(ListDirectoryTool);

        // Test non-existent path
        let input = json!({
            "path": "project/nonexistent"
        });

        let result = cx
            .update(|cx| {
                tool.clone().run(
                    input,
                    Arc::default(),
                    project.clone(),
                    action_log.clone(),
                    model.clone(),
                    None,
                    cx,
                )
            })
            .output
            .await;

        assert!(result.is_err());
        assert!(result.unwrap_err().to_string().contains("Path not found"));

        // Test trying to list a file instead of directory
        let input = json!({
            "path": "project/file.txt"
        });

        let result = cx
            .update(|cx| tool.run(input, Arc::default(), project, action_log, model, None, cx))
            .output
            .await;

        assert!(result.is_err());
        assert!(
            result
                .unwrap_err()
                .to_string()
                .contains("is not a directory")
        );
    }

    #[gpui::test]
    async fn test_list_directory_security(cx: &mut TestAppContext) {
        init_test(cx);

        let fs = FakeFs::new(cx.executor());
        fs.insert_tree(
            path!("/project"),
            json!({
                "normal_dir": {
                    "file1.txt": "content",
                    "file2.txt": "content"
                },
                ".mysecrets": "SECRET_KEY=abc123",
                ".secretdir": {
                    "config": "special configuration",
                    "secret.txt": "secret content"
                },
                ".mymetadata": "custom metadata",
                "visible_dir": {
                    "normal.txt": "normal content",
                    "special.privatekey": "private key content",
                    "data.mysensitive": "sensitive data",
                    ".hidden_subdir": {
                        "hidden_file.txt": "hidden content"
                    }
                }
            }),
        )
        .await;

        // Configure settings explicitly
        cx.update(|cx| {
            SettingsStore::update_global(cx, |store, cx| {
                store.update_user_settings::<WorktreeSettings>(cx, |settings| {
                    settings.file_scan_exclusions = Some(vec![
                        "**/.secretdir".to_string(),
                        "**/.mymetadata".to_string(),
                        "**/.hidden_subdir".to_string(),
                    ]);
                    settings.private_files = Some(vec![
                        "**/.mysecrets".to_string(),
                        "**/*.privatekey".to_string(),
                        "**/*.mysensitive".to_string(),
                    ]);
                });
            });
        });

        let project = Project::test(fs.clone(), [path!("/project").as_ref()], cx).await;
        let action_log = cx.new(|_| ActionLog::new(project.clone()));
        let model = Arc::new(FakeLanguageModel::default());
        let tool = Arc::new(ListDirectoryTool);

        // Listing root directory should exclude private and excluded files
        let input = json!({
            "path": "project"
        });

        let result = cx
            .update(|cx| {
                tool.clone().run(
                    input,
                    Arc::default(),
                    project.clone(),
                    action_log.clone(),
                    model.clone(),
                    None,
                    cx,
                )
            })
            .output
            .await
            .unwrap();

        let content = result.content.as_str().unwrap();

        // Should include normal directories
        assert!(content.contains("normal_dir"), "Should list normal_dir");
        assert!(content.contains("visible_dir"), "Should list visible_dir");

        // Should NOT include excluded or private files
        assert!(
            !content.contains(".secretdir"),
            "Should not list .secretdir (file_scan_exclusions)"
        );
        assert!(
            !content.contains(".mymetadata"),
            "Should not list .mymetadata (file_scan_exclusions)"
        );
        assert!(
            !content.contains(".mysecrets"),
            "Should not list .mysecrets (private_files)"
        );

        // Trying to list an excluded directory should fail
        let input = json!({
            "path": "project/.secretdir"
        });

        let result = cx
            .update(|cx| {
                tool.clone().run(
                    input,
                    Arc::default(),
                    project.clone(),
                    action_log.clone(),
                    model.clone(),
                    None,
                    cx,
                )
            })
            .output
            .await;

        assert!(
            result.is_err(),
            "Should not be able to list excluded directory"
        );
        assert!(
            result
                .unwrap_err()
                .to_string()
                .contains("file_scan_exclusions"),
            "Error should mention file_scan_exclusions"
        );

        // Listing a directory should exclude private files within it
        let input = json!({
            "path": "project/visible_dir"
        });

        let result = cx
            .update(|cx| {
                tool.clone().run(
                    input,
                    Arc::default(),
                    project.clone(),
                    action_log.clone(),
                    model.clone(),
                    None,
                    cx,
                )
            })
            .output
            .await
            .unwrap();

        let content = result.content.as_str().unwrap();

        // Should include normal files
        assert!(content.contains("normal.txt"), "Should list normal.txt");

        // Should NOT include private files
        assert!(
            !content.contains("privatekey"),
            "Should not list .privatekey files (private_files)"
        );
        assert!(
            !content.contains("mysensitive"),
            "Should not list .mysensitive files (private_files)"
        );

        // Should NOT include subdirectories that match exclusions
        assert!(
            !content.contains(".hidden_subdir"),
            "Should not list .hidden_subdir (file_scan_exclusions)"
        );
    }

    #[gpui::test]
    async fn test_list_directory_with_multiple_worktree_settings(cx: &mut TestAppContext) {
        init_test(cx);

        let fs = FakeFs::new(cx.executor());

        // Create first worktree with its own private files
        fs.insert_tree(
            path!("/worktree1"),
            json!({
                ".zed": {
                    "settings.json": r#"{
                        "file_scan_exclusions": ["**/fixture.*"],
                        "private_files": ["**/secret.rs", "**/config.toml"]
                    }"#
                },
                "src": {
                    "main.rs": "fn main() { println!(\"Hello from worktree1\"); }",
                    "secret.rs": "const API_KEY: &str = \"secret_key_1\";",
                    "config.toml": "[database]\nurl = \"postgres://localhost/db1\""
                },
                "tests": {
                    "test.rs": "mod tests { fn test_it() {} }",
                    "fixture.sql": "CREATE TABLE users (id INT, name VARCHAR(255));"
                }
            }),
        )
        .await;

        // Create second worktree with different private files
        fs.insert_tree(
            path!("/worktree2"),
            json!({
                ".zed": {
                    "settings.json": r#"{
                        "file_scan_exclusions": ["**/internal.*"],
                        "private_files": ["**/private.js", "**/data.json"]
                    }"#
                },
                "lib": {
                    "public.js": "export function greet() { return 'Hello from worktree2'; }",
                    "private.js": "const SECRET_TOKEN = \"private_token_2\";",
                    "data.json": "{\"api_key\": \"json_secret_key\"}"
                },
                "docs": {
                    "README.md": "# Public Documentation",
                    "internal.md": "# Internal Secrets and Configuration"
                }
            }),
        )
        .await;

        // Set global settings
        cx.update(|cx| {
            SettingsStore::update_global(cx, |store, cx| {
                store.update_user_settings::<WorktreeSettings>(cx, |settings| {
                    settings.file_scan_exclusions =
                        Some(vec!["**/.git".to_string(), "**/node_modules".to_string()]);
                    settings.private_files = Some(vec!["**/.env".to_string()]);
                });
            });
        });

        let project = Project::test(
            fs.clone(),
            [path!("/worktree1").as_ref(), path!("/worktree2").as_ref()],
            cx,
        )
        .await;

        // Wait for worktrees to be fully scanned
        cx.executor().run_until_parked();

        let action_log = cx.new(|_| ActionLog::new(project.clone()));
        let model = Arc::new(FakeLanguageModel::default());
        let tool = Arc::new(ListDirectoryTool);

        // Test listing worktree1/src - should exclude secret.rs and config.toml based on local settings
        let input = json!({
            "path": "worktree1/src"
        });

        let result = cx
            .update(|cx| {
                tool.clone().run(
                    input,
                    Arc::default(),
                    project.clone(),
                    action_log.clone(),
                    model.clone(),
                    None,
                    cx,
                )
            })
            .output
            .await
            .unwrap();

        let content = result.content.as_str().unwrap();
        assert!(content.contains("main.rs"), "Should list main.rs");
        assert!(
            !content.contains("secret.rs"),
            "Should not list secret.rs (local private_files)"
        );
        assert!(
            !content.contains("config.toml"),
            "Should not list config.toml (local private_files)"
        );

        // Test listing worktree1/tests - should exclude fixture.sql based on local settings
        let input = json!({
            "path": "worktree1/tests"
        });

        let result = cx
            .update(|cx| {
                tool.clone().run(
                    input,
                    Arc::default(),
                    project.clone(),
                    action_log.clone(),
                    model.clone(),
                    None,
                    cx,
                )
            })
            .output
            .await
            .unwrap();

        let content = result.content.as_str().unwrap();
        assert!(content.contains("test.rs"), "Should list test.rs");
        assert!(
            !content.contains("fixture.sql"),
            "Should not list fixture.sql (local file_scan_exclusions)"
        );

        // Test listing worktree2/lib - should exclude private.js and data.json based on local settings
        let input = json!({
            "path": "worktree2/lib"
        });

        let result = cx
            .update(|cx| {
                tool.clone().run(
                    input,
                    Arc::default(),
                    project.clone(),
                    action_log.clone(),
                    model.clone(),
                    None,
                    cx,
                )
            })
            .output
            .await
            .unwrap();

        let content = result.content.as_str().unwrap();
        assert!(content.contains("public.js"), "Should list public.js");
        assert!(
            !content.contains("private.js"),
            "Should not list private.js (local private_files)"
        );
        assert!(
            !content.contains("data.json"),
            "Should not list data.json (local private_files)"
        );

        // Test listing worktree2/docs - should exclude internal.md based on local settings
        let input = json!({
            "path": "worktree2/docs"
        });

        let result = cx
            .update(|cx| {
                tool.clone().run(
                    input,
                    Arc::default(),
                    project.clone(),
                    action_log.clone(),
                    model.clone(),
                    None,
                    cx,
                )
            })
            .output
            .await
            .unwrap();

        let content = result.content.as_str().unwrap();
        assert!(content.contains("README.md"), "Should list README.md");
        assert!(
            !content.contains("internal.md"),
            "Should not list internal.md (local file_scan_exclusions)"
        );

        // Test trying to list an excluded directory directly
        let input = json!({
            "path": "worktree1/src/secret.rs"
        });

        let result = cx
            .update(|cx| {
                tool.clone().run(
                    input,
                    Arc::default(),
                    project.clone(),
                    action_log.clone(),
                    model.clone(),
                    None,
                    cx,
                )
            })
            .output
            .await;

        // This should fail because we're trying to list a file, not a directory
        assert!(result.is_err(), "Should fail when trying to list a file");
    }
}