use std::path::PathBuf;

use crate::api::schema::{
    EventData, EventEnvelope, EventKind, ResponseResult, WorkspaceCreateParams,
    WorkspaceMoveParams, WorkspaceRenameParams, WorkspaceTarget,
};
use crate::app::App;

use super::responses::{encode_error, encode_success};

impl App {
    pub(super) fn handle_workspace_list(&mut self, id: String) -> String {
        encode_success(
            id,
            ResponseResult::WorkspaceList {
                workspaces: self.workspace_list_info(),
            },
        )
    }

    pub(super) fn handle_workspace_get(&mut self, id: String, target: WorkspaceTarget) -> String {
        let Some(index) = self.parse_workspace_id(&target.workspace_id) else {
            return workspace_not_found(id, &target.workspace_id);
        };
        let Some(_) = self.state.workspaces.get(index) else {
            return workspace_not_found(id, &target.workspace_id);
        };

        encode_success(
            id,
            ResponseResult::WorkspaceInfo {
                workspace: self.workspace_info(index),
            },
        )
    }

    pub(super) fn handle_workspace_create(
        &mut self,
        id: String,
        params: WorkspaceCreateParams,
    ) -> String {
        let cwd = params.cwd.map(PathBuf::from).unwrap_or_else(|| {
            let follow_cwd = self.workspace_creation_source().and_then(|ws_idx| {
                self.focused_pane_cwd_in_workspace(ws_idx)
                    .or_else(|| self.seed_cwd_from_workspace(ws_idx))
            });
            self.resolve_new_terminal_cwd(follow_cwd)
        });
        let extra_env = match super::env::normalize_launch_env(params.env) {
            Ok(env) => env,
            Err((code, message)) => return encode_error(id, &code, message),
        };
        match self.create_workspace_with_launch_env(cwd, params.focus, extra_env) {
            Ok(index) => {
                if let Some(label) = params.label {
                    if let Some(workspace) = self.state.workspaces.get_mut(index) {
                        workspace.set_custom_name(label);
                        crate::logging::workspace_renamed(&workspace.id);
                    }
                }
                self.emit_workspace_open_events(index);
                encode_success(
                    id,
                    self.workspace_created_result(index)
                        .expect("new workspace should produce a complete create response"),
                )
            }
            Err(err) => encode_error(id, "workspace_create_failed", err.to_string()),
        }
    }

    pub(super) fn handle_workspace_focus(&mut self, id: String, target: WorkspaceTarget) -> String {
        let Some(index) = self.parse_workspace_id(&target.workspace_id) else {
            return workspace_not_found(id, &target.workspace_id);
        };
        if self.state.workspaces.get(index).is_none() {
            return workspace_not_found(id, &target.workspace_id);
        }
        self.state.switch_workspace(index);

        encode_success(
            id,
            ResponseResult::WorkspaceInfo {
                workspace: self.workspace_info(index),
            },
        )
    }

    pub(super) fn handle_workspace_rename(
        &mut self,
        id: String,
        params: WorkspaceRenameParams,
    ) -> String {
        let Some(index) = self.parse_workspace_id(&params.workspace_id) else {
            return workspace_not_found(id, &params.workspace_id);
        };
        let Some(ws) = self.state.workspaces.get_mut(index) else {
            return workspace_not_found(id, &params.workspace_id);
        };
        ws.set_custom_name(params.label.clone());
        crate::logging::workspace_renamed(&ws.id);
        self.schedule_session_save();
        self.emit_event(EventEnvelope {
            event: EventKind::WorkspaceRenamed,
            data: EventData::WorkspaceRenamed {
                workspace_id: self.public_workspace_id(index),
                label: params.label,
            },
        });

        encode_success(
            id,
            ResponseResult::WorkspaceInfo {
                workspace: self.workspace_info(index),
            },
        )
    }

    pub(super) fn handle_workspace_move(
        &mut self,
        id: String,
        params: WorkspaceMoveParams,
    ) -> String {
        let Some(index) = self.parse_workspace_id(&params.workspace_id) else {
            return workspace_not_found(id, &params.workspace_id);
        };
        if self.state.workspaces.get(index).is_none() {
            return workspace_not_found(id, &params.workspace_id);
        }
        if params.insert_index > self.state.workspaces.len() {
            return encode_error(
                id,
                "workspace_move_failed",
                format!("insert_index {} is out of bounds", params.insert_index),
            );
        }

        let workspace_id = self.public_workspace_id(index);
        let insert_index = params.insert_index;
        let moved = self.state.move_workspace(index, insert_index);
        let workspaces = self.workspace_list_info();
        if moved {
            self.emit_event(EventEnvelope {
                event: EventKind::WorkspaceMoved,
                data: EventData::WorkspaceMoved {
                    workspace_id,
                    insert_index,
                    workspaces: workspaces.clone(),
                },
            });
        }

        encode_success(id, ResponseResult::WorkspaceList { workspaces })
    }

    pub(super) fn handle_workspace_close(&mut self, id: String, target: WorkspaceTarget) -> String {
        let Some(index) = self.parse_workspace_id(&target.workspace_id) else {
            return workspace_not_found(id, &target.workspace_id);
        };
        if self.state.workspaces.get(index).is_none() {
            return workspace_not_found(id, &target.workspace_id);
        }
        let workspace_id = self.public_workspace_id(index);
        let workspace = self.workspace_info(index);
        let pane_ids = self
            .state
            .workspaces
            .get(index)
            .map(|ws| {
                ws.tabs
                    .iter()
                    .flat_map(|tab| tab.layout.pane_ids())
                    .collect::<Vec<_>>()
            })
            .unwrap_or_default();
        self.state.selected = index;
        self.state.close_selected_workspace();
        for pane_id in pane_ids {
            self.state.plugin_panes.remove(&pane_id);
        }
        self.shutdown_detached_terminal_runtimes();
        self.emit_event(EventEnvelope {
            event: EventKind::WorkspaceClosed,
            data: EventData::WorkspaceClosed {
                workspace_id,
                workspace: Some(workspace),
            },
        });

        encode_success(id, ResponseResult::Ok {})
    }

    fn workspace_list_info(&self) -> Vec<crate::api::schema::WorkspaceInfo> {
        self.state
            .workspaces
            .iter()
            .enumerate()
            .map(|(idx, _)| self.workspace_info(idx))
            .collect()
    }
}

fn workspace_not_found(id: String, workspace_id: &str) -> String {
    encode_error(
        id,
        "workspace_not_found",
        format!("workspace {workspace_id} not found"),
    )
}

#[cfg(test)]
mod tests {
    use super::*;
    use crate::{api::schema::SuccessResponse, config::Config, workspace::Workspace};

    // `new_cwd = follow` must anchor on the focused pane for every creation
    // surface. Splits and tabs already do; a new workspace must follow the
    // focused pane too, not the source workspace's first-tab root pane.
    #[tokio::test]
    async fn workspace_create_follows_focused_pane_cwd_not_first_tab_root() {
        use super::super::test_support::{exiting_test_command, shutdown_test_runtimes};
        use crate::config::ShellModeConfig;

        let (_api_tx, api_rx) = tokio::sync::mpsc::unbounded_channel();
        let mut app = App::new(
            &Config::default(),
            true,
            None,
            api_rx,
            crate::api::EventHub::default(),
        );
        app.state.default_shell = exiting_test_command().into();
        app.state.shell_mode = ShellModeConfig::NonLogin;
        app.state.workspaces = vec![Workspace::test_new("spaces")];
        app.state.active = Some(0);
        app.state.selected = 0;
        app.state.ensure_test_terminals();

        // Second tab becomes the focused pane, away from tab 1's root pane.
        let response = app.handle_tab_create(
            "tab".into(),
            crate::api::schema::TabCreateParams {
                workspace_id: None,
                cwd: None,
                focus: true,
                label: None,
                env: Default::default(),
            },
        );
        let _: SuccessResponse = serde_json::from_str(&response).unwrap();
        // Drop runtimes so cwd resolution deterministically uses cached state.
        shutdown_test_runtimes(&mut app);

        let focused_cwd = std::env::temp_dir().join(format!(
            "herdr-ws-follow-{}-{}",
            std::process::id(),
            std::time::SystemTime::now()
                .duration_since(std::time::UNIX_EPOCH)
                .unwrap()
                .as_nanos()
        ));
        std::fs::create_dir_all(&focused_cwd).unwrap();
        let ws = &app.state.workspaces[0];
        let root_cwd = ws.identity_cwd.clone();
        let focused_pane = ws.focused_pane_id().unwrap();
        assert_ne!(focused_pane, ws.tabs[0].root_pane);
        let terminal_id = ws.terminal_id(focused_pane).cloned().unwrap();
        app.state.terminals.get_mut(&terminal_id).unwrap().cwd = focused_cwd.clone();

        let response = app.handle_workspace_create(
            "req".into(),
            WorkspaceCreateParams {
                cwd: None,
                focus: false,
                label: None,
                env: Default::default(),
            },
        );

        let success: SuccessResponse = serde_json::from_str(&response).unwrap();
        assert!(matches!(
            success.result,
            ResponseResult::WorkspaceCreated { .. }
        ));
        let created_cwd = &app.state.workspaces[1].identity_cwd;
        assert_eq!(
            crate::worktree::canonical_or_original(created_cwd),
            crate::worktree::canonical_or_original(&focused_cwd)
        );
        assert_ne!(
            crate::worktree::canonical_or_original(created_cwd),
            crate::worktree::canonical_or_original(&root_cwd)
        );
        shutdown_test_runtimes(&mut app);
        let _ = std::fs::remove_dir_all(&focused_cwd);
    }

    fn app_with_linked_worktree() -> App {
        let (_api_tx, api_rx) = tokio::sync::mpsc::unbounded_channel();
        let mut app = App::new(
            &Config::default(),
            true,
            None,
            api_rx,
            crate::api::EventHub::default(),
        );
        app.state.workspaces = vec![Workspace::test_new("issue")];
        app.state.workspaces[0].worktree_space = Some(crate::workspace::WorktreeSpaceMembership {
            key: "repo-key".into(),
            label: "herdr".into(),
            repo_root: "/repo/herdr".into(),
            checkout_path: "/repo/herdr-issue".into(),
            is_linked_worktree: true,
        });
        app
    }

    #[test]
    fn api_workspace_close_closes_linked_worktree_workspace_only() {
        let mut app = app_with_linked_worktree();

        let response = app.handle_workspace_close(
            "req".into(),
            WorkspaceTarget {
                workspace_id: app.state.workspaces[0].id.clone(),
            },
        );

        let success: SuccessResponse = serde_json::from_str(&response).unwrap();
        assert_eq!(success.id, "req");
        assert_eq!(app.state.request_remove_linked_worktree, None);
        assert!(app.state.workspaces.is_empty());
    }

    #[test]
    fn api_workspace_close_event_includes_final_worktree_snapshot() {
        let event_hub = crate::api::EventHub::default();
        let (_api_tx, api_rx) = tokio::sync::mpsc::unbounded_channel();
        let mut app = App::new(&Config::default(), true, None, api_rx, event_hub.clone());
        app.state.workspaces = app_with_linked_worktree().state.workspaces;
        let workspace_id = app.state.workspaces[0].id.clone();

        let response = app.handle_workspace_close(
            "req".into(),
            WorkspaceTarget {
                workspace_id: workspace_id.clone(),
            },
        );

        let success: SuccessResponse = serde_json::from_str(&response).unwrap();
        assert_eq!(success.id, "req");
        let events = event_hub.events_after(0);
        assert!(events.iter().any(|(_, event)| {
            matches!(
                &event.data,
                EventData::WorkspaceClosed {
                    workspace_id: closed_id,
                    workspace: Some(workspace),
                } if closed_id == &workspace_id
                    && workspace
                        .worktree
                        .as_ref()
                        .is_some_and(|worktree| worktree.is_linked_worktree)
            )
        }));
    }

    #[test]
    fn api_workspace_move_reorders_workspaces() {
        let event_hub = crate::api::EventHub::default();
        let (_api_tx, api_rx) = tokio::sync::mpsc::unbounded_channel();
        let mut app = App::new(&Config::default(), true, None, api_rx, event_hub.clone());
        app.state.workspaces = vec![
            Workspace::test_new("one"),
            Workspace::test_new("two"),
            Workspace::test_new("three"),
        ];
        app.state.active = Some(0);
        app.state.selected = 0;
        let moved_id = app.public_workspace_id(0);

        let response = app.handle_workspace_move(
            "req".into(),
            WorkspaceMoveParams {
                workspace_id: moved_id.clone(),
                insert_index: 3,
            },
        );

        let success: SuccessResponse = serde_json::from_str(&response).unwrap();
        let ResponseResult::WorkspaceList { workspaces } = success.result else {
            panic!("expected workspace list");
        };
        assert_eq!(workspaces[2].workspace_id, moved_id);
        assert_eq!(app.state.workspaces[2].display_name(), "one");
        let events = event_hub.events_after(0);
        assert!(events.iter().any(|(_, event)| {
            matches!(
                &event.data,
                EventData::WorkspaceMoved {
                    workspace_id,
                    insert_index: 3,
                    workspaces,
                } if workspace_id == &moved_id
                    && workspaces[2].workspace_id == moved_id
            )
        }));
    }

    #[test]
    fn api_workspace_move_noop_does_not_emit_event() {
        let event_hub = crate::api::EventHub::default();
        let (_api_tx, api_rx) = tokio::sync::mpsc::unbounded_channel();
        let mut app = App::new(&Config::default(), true, None, api_rx, event_hub.clone());
        app.state.workspaces = vec![Workspace::test_new("one"), Workspace::test_new("two")];
        let moved_id = app.public_workspace_id(0);

        let response = app.handle_workspace_move(
            "req".into(),
            WorkspaceMoveParams {
                workspace_id: moved_id.clone(),
                insert_index: 1,
            },
        );

        let success: SuccessResponse = serde_json::from_str(&response).unwrap();
        let ResponseResult::WorkspaceList { workspaces } = success.result else {
            panic!("expected workspace list");
        };
        assert_eq!(workspaces[0].workspace_id, moved_id);
        assert!(event_hub.events_after(0).is_empty());
    }
}