from textual.app import ComposeResult
from textual.screen import Screen
from textual.widgets import Header, Footer, Static, Button, Select, Input, RadioSet, RadioButton
from textual.containers import Vertical, Horizontal
from textual import work, on

from tui.config import list_conf_dir
from tui.backend import run_cli, stream_cli
from tui.widgets import ConfirmDialog, OperationLog


class RestoreScreen(Screen):

    BINDINGS = [("escape", "go_back", "Back")]

    def compose(self) -> ComposeResult:
        yield Header()
        targets = list_conf_dir("targets.d")
        remotes = list_conf_dir("remotes.d")
        with Vertical(id="restore-screen"):
            yield Static("Restore", id="screen-title")
            if not targets or not remotes:
                yield Static("Both targets and remotes must be configured for restore.")
            else:
                yield Static("Target:")
                yield Select([(t, t) for t in targets], id="restore-target", prompt="Select target")
                yield Static("Remote:")
                yield Select([(r, r) for r in remotes], id="restore-remote", prompt="Select remote")
                yield Static("Snapshot:")
                yield Select([], id="restore-snapshot", prompt="Select target and remote first")
                yield Static("Restore location:")
                with RadioSet(id="restore-location"):
                    yield RadioButton("In-place (original)", value=True)
                    yield RadioButton("Custom directory")
                yield Input(placeholder="Destination directory (e.g. /tmp/restore)", id="restore-dest")
                with Horizontal(id="restore-buttons"):
                    yield Button("Restore", variant="primary", id="btn-restore")
                    yield Button("Back", id="btn-back")
        yield Footer()

    @on(Select.Changed, "#restore-target")
    @on(Select.Changed, "#restore-remote")
    def _on_selection_changed(self, event: Select.Changed) -> None:
        self._try_load_snapshots()

    @work
    async def _try_load_snapshots(self) -> None:
        try:
            target_sel = self.query_one("#restore-target", Select)
            remote_sel = self.query_one("#restore-remote", Select)
        except Exception:
            return
        if target_sel.value is Select.BLANK or remote_sel.value is Select.BLANK:
            return
        target = str(target_sel.value)
        remote = str(remote_sel.value)
        snap_sel = self.query_one("#restore-snapshot", Select)
        snap_sel.set_options([])
        self.notify(f"Loading snapshots for {target}/{remote}...")
        rc, stdout, stderr = await run_cli("snapshots", "list", f"--target={target}", f"--remote={remote}")
        lines = [l.strip() for l in stdout.splitlines() if l.strip() and not l.startswith("===")]
        if lines:
            snap_sel.set_options([(s, s) for s in lines])
        else:
            self.notify("No snapshots found", severity="warning")

    def on_button_pressed(self, event: Button.Pressed) -> None:
        if event.button.id == "btn-back":
            self.app.pop_screen()
        elif event.button.id == "btn-restore":
            self._start_restore()

    def _start_restore(self) -> None:
        target_sel = self.query_one("#restore-target", Select)
        remote_sel = self.query_one("#restore-remote", Select)
        snap_sel = self.query_one("#restore-snapshot", Select)
        if target_sel.value is Select.BLANK:
            self.notify("Select a target", severity="error")
            return
        if remote_sel.value is Select.BLANK:
            self.notify("Select a remote", severity="error")
            return
        if snap_sel.value is Select.BLANK:
            self.notify("Select a snapshot", severity="error")
            return
        target = str(target_sel.value)
        remote = str(remote_sel.value)
        snapshot = str(snap_sel.value)
        radio = self.query_one("#restore-location", RadioSet)
        dest_input = self.query_one("#restore-dest", Input)
        dest = "" if radio.pressed_index == 0 else dest_input.value
        msg = f"Restore snapshot?\n\nTarget: {target}\nRemote: {remote}\nSnapshot: {snapshot}"
        if dest:
            msg += f"\nDestination: {dest}"
        else:
            msg += "\nLocation: In-place"
        self.app.push_screen(
            ConfirmDialog(msg, "Confirm Restore"),
            callback=lambda ok: self._do_restore(target, remote, snapshot, dest) if ok else None,
        )

    @work
    async def _do_restore(self, target: str, remote: str, snapshot: str, dest: str) -> None:
        log_screen = OperationLog(f"Restore: {target}")
        self.app.push_screen(log_screen)
        args = ["restore", f"--target={target}", f"--remote={remote}", f"--snapshot={snapshot}"]
        if dest:
            args.append(f"--dest={dest}")
        rc = await stream_cli(log_screen.write, *args)
        if rc == 0:
            log_screen.write("\n[green]Restore completed successfully.[/green]")
        else:
            log_screen.write(f"\n[red]Restore failed (exit code {rc}).[/red]")

    def action_go_back(self) -> None:
        self.app.pop_screen()