// file: crates/ksp-app-backfill-desk/src/tauri.rs
// version: 9

//! Tauri runtime assembly for the KSP Backfill desktop application.

use tauri::Emitter; // rust-rules: trait-import
use tauri::Manager; // rust-rules: trait-import

/// Runs the Backfill desktop application.
#[cfg_attr(mobile, tauri::mobile_entry_point)]
pub fn run(arguments: &[std::ffi::OsString]) -> ksp_core_lib::Result<()> {
    let context = tauri::generate_context!();
    let runtime_layout = configure_packaged_runtime(&context);
    if let std::result::Result::Err(error) = runtime_layout {
        return std::result::Result::Err(error);
    }
    let app_state = crate::AppState::initialize(arguments);
    let app_state = match app_state {
        std::result::Result::Ok(value) => value,
        std::result::Result::Err(error) => return std::result::Result::Err(error),
    };
    let mut builder = tauri::Builder::default();
    builder = configure_state(builder, app_state);
    builder = configure_plugins(builder);
    builder = configure_commands(builder);
    builder = configure_setup(builder);
    builder = configure_window_events(builder);
    let run_result = builder.run(context);
    return match run_result {
        std::result::Result::Ok(()) => std::result::Result::Ok(()),
        std::result::Result::Err(error) => std::result::Result::Err(
            ksp_core_lib::Error::new(crate::ERROR_CODE_TAURI_RUNTIME_FAILED, "Cannot run KSP Backfill Desk Tauri runtime")
                .with_context("tauri_error", error.to_string()),
        ),
    };
}

fn configure_packaged_runtime(context: &tauri::Context<tauri::Wry>) -> ksp_core_lib::Result<()> {
    if cfg!(debug_assertions) {
        return std::result::Result::Ok(());
    }
    let resource_root = tauri::utils::platform::resource_dir(context.package_info(), &tauri::Env::default());
    let resource_root = match resource_root {
        std::result::Result::Ok(value) => value,
        std::result::Result::Err(error) => {
            return std::result::Result::Err(
                ksp_core_lib::Error::new(crate::ERROR_CODE_TAURI_RUNTIME_FAILED, "Cannot resolve packaged Tauri resource directory")
                    .with_context("tauri_error", error.to_string()),
            );
        },
    };
    let layout = ksp_config_lib::prepare_packaged_runtime(resource_root.as_path());
    let layout = match layout {
        std::result::Result::Ok(value) => value,
        std::result::Result::Err(error) => return std::result::Result::Err(error),
    };
    let working_directory = std::env::set_current_dir(layout.runtime_root());
    return match working_directory {
        std::result::Result::Ok(()) => std::result::Result::Ok(()),
        std::result::Result::Err(error) => std::result::Result::Err(
            ksp_core_lib::Error::new(crate::ERROR_CODE_TAURI_RUNTIME_FAILED, "Cannot activate packaged KSP runtime directory")
                .with_context("runtime_root", layout.runtime_root().to_string_lossy().into_owned())
                .with_source(error),
        ),
    };
}

fn configure_state(builder: tauri::Builder<tauri::Wry>, app_state: crate::AppState) -> tauri::Builder<tauri::Wry> {
    return builder.manage(app_state);
}

fn configure_plugins(builder: tauri::Builder<tauri::Wry>) -> tauri::Builder<tauri::Wry> {
    let tracing_plugin = tauri_plugin_tracing::Builder::new().build::<tauri::Wry>();
    return builder.plugin(tracing_plugin);
}

#[allow(clippy::question_mark_used)] // Tauri generates the question-mark operator internally for async command dispatch.
fn configure_commands(builder: tauri::Builder<tauri::Wry>) -> tauri::Builder<tauri::Wry> {
    return builder.invoke_handler(tauri::generate_handler![
        backfill_cancel,
        backfill_options,
        backfill_resume,
        backfill_start,
        backfill_status,
        backfill_validate_request,
        emit_frontend_log,
        get_runtime_status,
        splash_frontend_ready
    ]);
}

fn configure_setup(builder: tauri::Builder<tauri::Wry>) -> tauri::Builder<tauri::Wry> {
    return builder.setup(|app| {
        let splash = crate::require_splash_window(app);
        if let std::result::Result::Err(error) = splash {
            return std::result::Result::Err(std::boxed::Box::new(error));
        }
        let main = crate::require_main_window(app);
        if let std::result::Result::Err(error) = main {
            return std::result::Result::Err(std::boxed::Box::new(error));
        }
        ksp_logging_lib::debug!(target: crate::TRACING_TARGET, domain = crate::TRACING_DOMAIN_SHELL, "Backfill Desk Tauri shell setup completed");
        return std::result::Result::Ok(());
    });
}

fn configure_window_events(builder: tauri::Builder<tauri::Wry>) -> tauri::Builder<tauri::Wry> {
    return builder.on_window_event(|window, event| {
        if window.label() != "main" {
            return;
        }
        if let tauri::WindowEvent::CloseRequested { api, .. } = event {
            api.prevent_close();
            let app_handle = window.app_handle().clone();
            let state = app_handle.state::<crate::AppState>();
            if !state.begin_shutdown() {
                return;
            }
            let cancellation = state.cancel_active_backfill_for_shutdown();
            match cancellation {
                std::result::Result::Ok(accepted) => {
                    ksp_logging_lib::debug!(
                        target: crate::TRACING_TARGET,
                        domain = crate::TRACING_DOMAIN_WINDOWS,
                        cancellation_accepted = accepted,
                        "Backfill Desk main-window close requested; cooperative Backfill cancellation attempted before bounded Store shutdown"
                    );
                },
                std::result::Result::Err(error) => {
                    ksp_logging_lib::warn!(
                        target: crate::TRACING_TARGET,
                        domain = crate::TRACING_DOMAIN_WINDOWS,
                        error_domain = error.code().domain(),
                        error_code = error.code().code(),
                        "Backfill Desk could not request cooperative cancellation during shutdown; continuing bounded shutdown"
                    );
                },
            }
            tauri::async_runtime::spawn(async move {
                let state = app_handle.state::<crate::AppState>();
                let closed = state.close_store().await;
                match closed {
                    std::result::Result::Ok(()) => {
                        ksp_logging_lib::debug!(
                            target: crate::TRACING_TARGET,
                            domain = crate::TRACING_DOMAIN_WINDOWS,
                            "Backfill Desk Store shutdown completed; exiting application"
                        );
                    },
                    std::result::Result::Err(error) => {
                        ksp_logging_lib::warn!(
                            target: crate::TRACING_TARGET,
                            domain = crate::TRACING_DOMAIN_WINDOWS,
                            error_domain = error.code().domain(),
                            error_code = error.code().code(),
                            "Backfill Desk Store shutdown failed; exiting application after bounded close attempt"
                        );
                    },
                }
                app_handle.exit(0);
            });
        }
    });
}

fn project_command_error(command: &'static str, domain: &'static str, error: &ksp_core_lib::Error) -> crate::CommandErrorDto {
    ksp_logging_lib::warn!(
        target: crate::TRACING_TARGET,
        domain = domain,
        command = command,
        error_domain = error.code().domain(),
        error_code = error.code().code(),
        "Backfill Desk Tauri command failed"
    );
    return crate::CommandErrorDto::from_error(error);
}

#[tauri::command]
fn backfill_cancel(job_id: String, state: tauri::State<'_, crate::AppState>) -> std::result::Result<crate::BackfillCancelResponseDto, crate::CommandErrorDto> {
    let result = state.cancel_backfill(job_id.as_str());
    return match result {
        std::result::Result::Ok(value) => std::result::Result::Ok(value),
        std::result::Result::Err(error) => std::result::Result::Err(project_command_error("backfill_cancel", crate::TRACING_DOMAIN_RUN, &error)),
    };
}

#[tauri::command]
fn backfill_options(state: tauri::State<'_, crate::AppState>) -> std::result::Result<crate::BackfillDeskOptionsDto, crate::CommandErrorDto> {
    let result = state.backfill_options();
    return match result {
        std::result::Result::Ok(value) => std::result::Result::Ok(value),
        std::result::Result::Err(error) => std::result::Result::Err(project_command_error("backfill_options", crate::TRACING_DOMAIN_TRANSPORT, &error)),
    };
}

#[tauri::command]
fn backfill_start(
    app: tauri::AppHandle,
    request: crate::BackfillStartRequestDto,
    state: tauri::State<'_, crate::AppState>,
) -> std::result::Result<crate::BackfillStartResponseDto, crate::CommandErrorDto> {
    let launch = state.prepare_backfill_start(request);
    let launch = match launch {
        std::result::Result::Ok(value) => value,
        std::result::Result::Err(error) => {
            return std::result::Result::Err(project_command_error("backfill_start", crate::TRACING_DOMAIN_RUN, &error));
        },
    };
    let response = launch.response();
    spawn_backfill_launch(app, launch);
    return std::result::Result::Ok(response);
}

#[tauri::command]
fn backfill_resume(
    app: tauri::AppHandle,
    state: tauri::State<'_, crate::AppState>,
) -> std::result::Result<crate::BackfillResumeResponseDto, crate::CommandErrorDto> {
    let launch = state.prepare_backfill_resume();
    let launch = match launch {
        std::result::Result::Ok(value) => value,
        std::result::Result::Err(error) => {
            return std::result::Result::Err(project_command_error("backfill_resume", crate::TRACING_DOMAIN_RUN, &error));
        },
    };
    let response = crate::BackfillResumeResponseDto {
        accepted: true,
        job_id: launch.job_id.as_str().to_owned(),
        state: ksp_job_api::JobState::Created.code().to_owned(),
    };
    spawn_backfill_launch(app, launch);
    return std::result::Result::Ok(response);
}

fn spawn_backfill_launch(app: tauri::AppHandle, launch: crate::BackfillRunLaunch) {
    let monitor_app = app.clone();
    let monitor_source = launch.snapshots.clone();
    let _monitor_task = tauri::async_runtime::spawn(async move {
        monitor_backfill_status(monitor_app, monitor_source).await;
    });
    let _run_task = tauri::async_runtime::spawn(async move {
        let state = app.state::<crate::AppState>();
        let executed = state.execute_backfill_run(launch).await;
        if let std::result::Result::Err(error) = executed {
            ksp_logging_lib::warn!(
                target: crate::TRACING_TARGET,
                domain = crate::TRACING_DOMAIN_RUN,
                error_domain = error.code().domain(),
                error_code = error.code().code(),
                "Backfill Desk async run terminated with an error"
            );
        }
    });
    return;
}

async fn monitor_backfill_status(app: tauri::AppHandle, source: ksp_job_backfill_lib::BackfillSnapshotSource) {
    let mut notification = <ksp_job_backfill_lib::BackfillSnapshotSource as ksp_job_api::JobSnapshotSource>::current(&source);
    loop {
        let projected = crate::project_backfill_status(&notification);
        match projected {
            std::result::Result::Ok(status) => {
                let main = app.get_webview_window("main");
                if let std::option::Option::Some(window) = main {
                    let emitted = window.emit(crate::BACKFILL_STATUS_EVENT_NAME, status);
                    if emitted.is_err() {
                        ksp_logging_lib::warn!(
                            target: crate::TRACING_TARGET,
                            domain = crate::TRACING_DOMAIN_RUN,
                            "Backfill Desk could not emit latest-value monitoring status to the main window"
                        );
                    }
                }
            },
            std::result::Result::Err(error) => {
                ksp_logging_lib::warn!(
                    target: crate::TRACING_TARGET,
                    domain = crate::TRACING_DOMAIN_RUN,
                    error_domain = error.code().domain(),
                    error_code = error.code().code(),
                    "Backfill Desk could not project latest-value monitoring status"
                );
            },
        }
        if notification.state().is_terminal() {
            return;
        }
        let observed = notification.sequence();
        notification = <ksp_job_backfill_lib::BackfillSnapshotSource as ksp_job_api::JobSnapshotSource>::wait_for_change(&source, observed).await;
    }
}

#[tauri::command]
fn backfill_status(state: tauri::State<'_, crate::AppState>) -> std::result::Result<std::option::Option<crate::BackfillRunStatusDto>, crate::CommandErrorDto> {
    let result = state.backfill_status();
    return match result {
        std::result::Result::Ok(value) => std::result::Result::Ok(value),
        std::result::Result::Err(error) => std::result::Result::Err(project_command_error("backfill_status", crate::TRACING_DOMAIN_RUN, &error)),
    };
}

#[tauri::command]
fn backfill_validate_request(
    request: crate::BackfillStartRequestDto,
    state: tauri::State<'_, crate::AppState>,
) -> std::result::Result<crate::BackfillRequestPreviewDto, crate::CommandErrorDto> {
    let result = state.validate_backfill_request(request);
    return match result {
        std::result::Result::Ok(value) => std::result::Result::Ok(value),
        std::result::Result::Err(error) => std::result::Result::Err(project_command_error("backfill_validate_request", crate::TRACING_DOMAIN_REQUEST, &error)),
    };
}

#[tauri::command]
fn emit_frontend_log(payload: crate::FrontendLogPayloadDto) -> std::result::Result<(), crate::CommandErrorDto> {
    let result = crate::emit_frontend_log_event(payload);
    return match result {
        std::result::Result::Ok(()) => std::result::Result::Ok(()),
        std::result::Result::Err(error) => std::result::Result::Err(project_command_error("emit_frontend_log", crate::TRACING_DOMAIN_FRONTEND, &error)),
    };
}

#[tauri::command]
fn get_runtime_status(state: tauri::State<'_, crate::AppState>) -> std::result::Result<crate::ShellStatusDto, crate::CommandErrorDto> {
    let result = state.shell_status();
    return match result {
        std::result::Result::Ok(value) => std::result::Result::Ok(value),
        std::result::Result::Err(error) => std::result::Result::Err(project_command_error("get_runtime_status", crate::TRACING_DOMAIN_SHELL, &error)),
    };
}

#[tauri::command]
async fn splash_frontend_ready(
    app: tauri::AppHandle,
    webview_window: tauri::WebviewWindow,
    state: tauri::State<'_, crate::AppState>,
) -> std::result::Result<(), crate::CommandErrorDto> {
    let result = crate::splash_frontend_ready_service(app, webview_window, &state).await;
    return match result {
        std::result::Result::Ok(()) => std::result::Result::Ok(()),
        std::result::Result::Err(error) => std::result::Result::Err(project_command_error("splash_frontend_ready", crate::TRACING_DOMAIN_WINDOWS, &error)),
    };
}