/**
 * Code validation component for PodTUI
 * 8-character alphanumeric code input for sync authentication
 */

import { createSignal } from "solid-js";
import { useAuthStore } from "@/stores/auth";
import { AUTH_CONFIG } from "@/config/auth";
import { useTheme } from "@/context/ThemeContext";

interface CodeValidationProps {
  focused?: boolean;
  onBack?: () => void;
}

type FocusField = "code" | "submit" | "back";

export function CodeValidation(props: CodeValidationProps) {
  const auth = useAuthStore();
  const { theme } = useTheme();
  const [code, setCode] = createSignal("");
  const [focusField, setFocusField] = createSignal<FocusField>("code");
  const [codeError, setCodeError] = createSignal<string | null>(null);

  const fields: FocusField[] = ["code", "submit", "back"];

  /** Format code as user types (uppercase, alphanumeric only) */
  const handleCodeInput = (value: string) => {
    const formatted = value.toUpperCase().replace(/[^A-Z0-9]/g, "");
    // Limit to max length
    const limited = formatted.slice(0, AUTH_CONFIG.codeValidation.codeLength);
    setCode(limited);

    // Clear error when typing
    if (codeError()) {
      setCodeError(null);
    }
  };

  const validateCode = (value: string): boolean => {
    if (!value) {
      setCodeError("Code is required");
      return false;
    }
    if (value.length !== AUTH_CONFIG.codeValidation.codeLength) {
      setCodeError(
        `Code must be ${AUTH_CONFIG.codeValidation.codeLength} characters`,
      );
      return false;
    }
    if (!AUTH_CONFIG.codeValidation.allowedChars.test(value)) {
      setCodeError("Code must contain only letters and numbers");
      return false;
    }
    setCodeError(null);
    return true;
  };

  const handleSubmit = async () => {
    if (!validateCode(code())) {
      return;
    }

    const success = await auth.validateCode(code());
    if (!success && auth.error) {
      setCodeError(auth.error.message);
    }
  };

  const handleKeyPress = (key: { name: string; shift?: boolean }) => {
    if (key.name === "tab") {
      const currentIndex = fields.indexOf(focusField());
      const nextIndex = key.shift
        ? (currentIndex - 1 + fields.length) % fields.length
        : (currentIndex + 1) % fields.length;
      setFocusField(fields[nextIndex]);
    } else if (key.name === "return" || key.name === "tab") {
      if (focusField() === "submit") {
        handleSubmit();
      } else if (focusField() === "back" && props.onBack) {
        props.onBack();
      }
    } else if (key.name === "escape" && props.onBack) {
      props.onBack();
    }
  };

  const codeProgress = () => {
    const len = code().length;
    const max = AUTH_CONFIG.codeValidation.codeLength;
    return `${len}/${max}`;
  };

  const codeDisplay = () => {
    const current = code();
    const max = AUTH_CONFIG.codeValidation.codeLength;
    const filled = current.split("");
    const empty = Array(max - filled.length).fill("_");
    return [...filled, ...empty].join(" ");
  };

  return (
    <box flexDirection="column" border padding={2} gap={1} borderColor={theme.border}>
      <text fg={theme.text}>
        <strong>Enter Sync Code</strong>
      </text>

      <box height={1} />

      <text fg={theme.textMuted}>
        Enter your 8-character sync code to link your account.
      </text>
      <text fg={theme.textMuted}>You can get this code from the web portal.</text>

      <box height={1} />

      {/* Code display */}
      <box flexDirection="column" gap={0}>
      <text fg={focusField() === "code" ? theme.primary : undefined}>
            Code ({codeProgress()}):
          </text>

        <box border padding={1} borderColor={theme.border}>
          <text
            fg={
              code().length === AUTH_CONFIG.codeValidation.codeLength
                ? theme.success
                : theme.warning
            }
          >
            {codeDisplay()}
          </text>
        </box>

        {/* Hidden input for actual typing */}
        <input
          value={code()}
          onInput={handleCodeInput}
          placeholder=""
          focused={props.focused && focusField() === "code"}
          width={30}
        />

        {codeError() && <text fg={theme.error}>{codeError()}</text>}
      </box>

      <box height={1} />

      {/* Action buttons */}
      <box flexDirection="row" gap={2}>
        <box
          border
          padding={1}
          backgroundColor={focusField() === "submit" ? theme.backgroundElement : undefined}
        >
          <text fg={focusField() === "submit" ? theme.primary : undefined}>
            {auth.isLoading ? "Validating..." : "[Enter] Validate Code"}
          </text>
        </box>

        <box
          border
          padding={1}
          backgroundColor={focusField() === "back" ? theme.backgroundElement : undefined}
        >
          <text fg={focusField() === "back" ? theme.warning : theme.textMuted}>
            [Esc] Back to Login
          </text>
        </box>
      </box>

      {/* Auth error message */}
      {auth.error && <text fg={theme.error}>{auth.error.message}</text>}

      <box height={1} />

      <text fg={theme.textMuted}>Tab to navigate, Enter to select, Esc to go back</text>
    </box>
  );
}