// Localised email copy. Keep keys stable across languages so the template
// builders can swap them by language code without dynamic imports.

type Lang = "en" | "de" | "fr" | "es" | "it";

interface VerificationCopy {
    subject: (code: string) => string;
    welcome: string;
    yourCode: string;
    orClick: string;
    button: string;
    expiresNote: string;
    footer: string;
}

interface ResetCopy {
    subject: string;
    intro: string;
    button: string;
    expiresNote: string;
    footer: string;
}

const VERIFICATION: Record<Lang, VerificationCopy> = {
    en: {
        subject: (c) => `${c} – Verify your email for My Weekly ToDo's`,
        welcome: "Welcome! Please verify your email address to complete your registration.",
        yourCode: "Your verification code",
        orClick: "Or click the button below to verify instantly:",
        button: "✓ Verify Email",
        expiresNote: "This code expires in 15 minutes. If you didn't create an account, you can safely ignore this email.",
        footer: "Simple. Beautiful. Yours.",
    },
    de: {
        subject: (c) => `${c} – Bestätige deine E-Mail-Adresse für My Weekly ToDo's`,
        welcome: "Willkommen! Bitte bestätige deine E-Mail-Adresse, um deine Registrierung abzuschließen.",
        yourCode: "Dein Bestätigungscode",
        orClick: "Oder klicke unten, um sofort zu bestätigen:",
        button: "✓ E-Mail bestätigen",
        expiresNote: "Dieser Code läuft in 15 Minuten ab. Falls du diesen Account nicht erstellt hast, kannst du diese E-Mail einfach ignorieren.",
        footer: "Einfach. Schön. Deins.",
    },
    fr: {
        subject: (c) => `${c} – Vérifiez votre adresse e-mail pour My Weekly ToDo's`,
        welcome: "Bienvenue ! Veuillez vérifier votre adresse e-mail pour terminer votre inscription.",
        yourCode: "Votre code de vérification",
        orClick: "Ou cliquez sur le bouton ci-dessous pour vérifier instantanément :",
        button: "✓ Vérifier l'e-mail",
        expiresNote: "Ce code expire dans 15 minutes. Si vous n'avez pas créé de compte, vous pouvez ignorer cet e-mail.",
        footer: "Simple. Beau. À vous.",
    },
    es: {
        subject: (c) => `${c} – Verifica tu correo para My Weekly ToDo's`,
        welcome: "¡Bienvenido! Por favor verifica tu dirección de correo para completar tu registro.",
        yourCode: "Tu código de verificación",
        orClick: "O haz clic en el botón de abajo para verificar al instante:",
        button: "✓ Verificar correo",
        expiresNote: "Este código expira en 15 minutos. Si no creaste una cuenta, puedes ignorar este correo.",
        footer: "Simple. Hermoso. Tuyo.",
    },
    it: {
        subject: (c) => `${c} – Verifica la tua email per My Weekly ToDo's`,
        welcome: "Benvenuto! Verifica il tuo indirizzo email per completare la registrazione.",
        yourCode: "Il tuo codice di verifica",
        orClick: "Oppure clicca sul pulsante qui sotto per verificare subito:",
        button: "✓ Verifica email",
        expiresNote: "Questo codice scade tra 15 minuti. Se non hai creato un account, puoi ignorare questa email.",
        footer: "Semplice. Bello. Tuo.",
    },
};

const RESET: Record<Lang, ResetCopy> = {
    en: {
        subject: "Password Reset – My Weekly ToDo's",
        intro: "We received a request to reset your password. Click the button below to choose a new one.",
        button: "Reset Password",
        expiresNote: "This link expires in 1 hour. If you didn't request a password reset, you can safely ignore this email.",
        footer: "Simple. Beautiful. Yours.",
    },
    de: {
        subject: "Passwort zurücksetzen – My Weekly ToDo's",
        intro: "Wir haben eine Anfrage zum Zurücksetzen deines Passworts erhalten. Klicke auf den Button unten, um ein neues Passwort zu wählen.",
        button: "Passwort zurücksetzen",
        expiresNote: "Dieser Link läuft in 1 Stunde ab. Falls du kein neues Passwort angefordert hast, kannst du diese E-Mail einfach ignorieren.",
        footer: "Einfach. Schön. Deins.",
    },
    fr: {
        subject: "Réinitialisation du mot de passe – My Weekly ToDo's",
        intro: "Nous avons reçu une demande de réinitialisation de votre mot de passe. Cliquez sur le bouton ci-dessous pour en choisir un nouveau.",
        button: "Réinitialiser le mot de passe",
        expiresNote: "Ce lien expire dans 1 heure. Si vous n'avez pas demandé de réinitialisation, vous pouvez ignorer cet e-mail.",
        footer: "Simple. Beau. À vous.",
    },
    es: {
        subject: "Restablecimiento de contraseña – My Weekly ToDo's",
        intro: "Recibimos una solicitud para restablecer tu contraseña. Haz clic en el botón de abajo para elegir una nueva.",
        button: "Restablecer contraseña",
        expiresNote: "Este enlace expira en 1 hora. Si no solicitaste un restablecimiento, puedes ignorar este correo.",
        footer: "Simple. Hermoso. Tuyo.",
    },
    it: {
        subject: "Reimpostazione password – My Weekly ToDo's",
        intro: "Abbiamo ricevuto una richiesta di reimpostazione della password. Clicca sul pulsante qui sotto per sceglierne una nuova.",
        button: "Reimposta password",
        expiresNote: "Questo link scade tra 1 ora. Se non hai richiesto la reimpostazione, puoi ignorare questa email.",
        footer: "Semplice. Bello. Tuo.",
    },
};

function pickLang(input?: string | null): Lang {
    if (!input) return "en";
    const code = input.toLowerCase().slice(0, 2);
    if (code === "de" || code === "fr" || code === "es" || code === "it" || code === "en") return code;
    return "en";
}

// Parse the first acceptable locale out of a raw Accept-Language header so we
// can pre-fill a user's UI language at signup.
export function languageFromAcceptLanguage(header?: string | null): Lang {
    if (!header) return "en";
    const tags = header.split(",").map((t) => t.trim().split(";")[0]);
    for (const t of tags) {
        const code = t.toLowerCase().slice(0, 2);
        if (code === "de" || code === "fr" || code === "es" || code === "it" || code === "en") return code;
    }
    return "en";
}

export function getVerificationCopy(language?: string | null): VerificationCopy {
    return VERIFICATION[pickLang(language)];
}

export function getResetCopy(language?: string | null): ResetCopy {
    return RESET[pickLang(language)];
}