"use client";

import { useState } from "react";
import { IconCode } from "@tabler/icons-react";
import { Card, CardContent, CardHeader, CardTitle } from "@kandev/ui/card";
import { Button } from "@kandev/ui/button";
import { Input } from "@kandev/ui/input";
import { Select, SelectContent, SelectItem, SelectTrigger, SelectValue } from "@kandev/ui/select";
import { SettingsSection } from "@/components/settings/settings-section";
import { useAppStore, useAppStoreApi } from "@/components/state-provider";
import { useShellSettings } from "@/hooks/domains/settings/use-shell-settings";
import { updateUserSettings } from "@/lib/api";
import { useRequest } from "@/lib/http/use-request";

const AUTO_SHELL = "auto";
const CUSTOM_SHELL = "custom";

type ShellOption = { value: string; label: string };

function resolveShellSelection(preferredShell: string, shellOptions: ShellOption[]) {
  if (!preferredShell) {
    return { selection: AUTO_SHELL, customShell: "" };
  }
  if (shellOptions.some((option) => option.value === preferredShell)) {
    return { selection: preferredShell, customShell: "" };
  }
  return { selection: CUSTOM_SHELL, customShell: preferredShell };
}

type ShellSelectProps = {
  shellSelection: string;
  onSelectionChange: (value: string) => void;
  customShell: string;
  onCustomShellChange: (value: string) => void;
  shellLoaded: boolean;
  shellOptions: ShellOption[];
};

function ShellSelect({
  shellSelection,
  onSelectionChange,
  customShell,
  onCustomShellChange,
  shellLoaded,
  shellOptions,
}: ShellSelectProps) {
  return (
    <>
      <div className="space-y-2">
        <Select
          value={shellSelection}
          onValueChange={onSelectionChange}
          disabled={!shellLoaded || shellOptions.length === 0}
        >
          <SelectTrigger>
            <SelectValue
              placeholder={
                shellOptions.length === 0 ? "Shell options unavailable" : "Select a shell"
              }
            />
          </SelectTrigger>
          <SelectContent>
            {shellOptions
              .filter(
                (option) =>
                  option.value !== AUTO_SHELL &&
                  option.value !== CUSTOM_SHELL &&
                  option.value !== "",
              )
              .map((option) => (
                <SelectItem key={option.value} value={option.value}>
                  {option.label}
                </SelectItem>
              ))}
            <SelectItem value={CUSTOM_SHELL}>Custom</SelectItem>
            <SelectItem value={AUTO_SHELL}>System default</SelectItem>
          </SelectContent>
        </Select>
      </div>
      {shellSelection === CUSTOM_SHELL && (
        <div className="space-y-2">
          <Input
            value={customShell}
            onChange={(event) => onCustomShellChange(event.target.value)}
            placeholder="/bin/zsh"
          />
          <p className="text-xs text-muted-foreground">
            Enter a shell path or command available in the agent environment.
          </p>
        </div>
      )}
    </>
  );
}

export function ShellSettingsCard() {
  const setUserSettings = useAppStore((state) => state.setUserSettings);
  const storeApi = useAppStoreApi();
  const shellSettings = useShellSettings();
  const initialShellValue = shellSettings.preferredShell ?? "";
  const initialShellOptions = shellSettings.shellOptions ?? [];
  const initialSelection = resolveShellSelection(initialShellValue, initialShellOptions);
  const [preferredShell, setPreferredShell] = useState(initialShellValue);
  const [baselineShell, setBaselineShell] = useState(initialShellValue);
  const [shellSelection, setShellSelection] = useState(initialSelection.selection);
  const [customShell, setCustomShell] = useState(initialSelection.customShell);
  const [shellLoaded] = useState(shellSettings.loaded);
  const [shellOptions] = useState<ShellOption[]>(initialShellOptions);

  const saveShellRequest = useRequest(async () => {
    const trimmed = preferredShell.trim();
    const currentSettings = storeApi.getState().userSettings;
    await updateUserSettings({
      workspace_id: currentSettings.workspaceId ?? "",
      repository_ids: currentSettings.repositoryIds,
      preferred_shell: trimmed,
    });
    setBaselineShell(trimmed);
    setUserSettings({
      ...currentSettings,
      preferredShell: trimmed || null,
      loaded: true,
    });
  });

  // Store data is SSR-hydrated for settings. Local state is initialized once.

  const shellDirty = preferredShell.trim() !== baselineShell.trim();

  return (
    <SettingsSection
      icon={<IconCode className="h-5 w-5" />}
      title="Shell"
      description="Pick the default shell for task sessions"
    >
      <Card>
        <CardHeader className="flex flex-row items-center justify-between gap-4">
          <CardTitle className="text-base">Preferred Shell</CardTitle>
          <Button
            type="button"
            onClick={() => saveShellRequest.run()}
            disabled={!shellLoaded || !shellDirty || saveShellRequest.isLoading}
          >
            {saveShellRequest.isLoading ? "Saving..." : "Save"}
          </Button>
        </CardHeader>
        <CardContent className="space-y-4">
          <ShellSelect
            shellSelection={shellSelection}
            onSelectionChange={(value) => {
              setShellSelection(value);
              if (value === AUTO_SHELL) {
                setPreferredShell("");
                setCustomShell("");
                return;
              }
              if (value === CUSTOM_SHELL) {
                setPreferredShell(customShell);
                return;
              }
              setPreferredShell(value);
              setCustomShell("");
            }}
            customShell={customShell}
            onCustomShellChange={(value) => {
              setCustomShell(value);
              setPreferredShell(value);
            }}
            shellLoaded={shellLoaded}
            shellOptions={shellOptions}
          />
          <p className="text-xs text-muted-foreground">
            New task sessions will use this shell. Existing sessions keep their current shell.
          </p>
        </CardContent>
      </Card>
    </SettingsSection>
  );
}