using QuestionsApi.Models;

namespace QuestionsApi.Services;

public sealed record LegalPolicyStatus(
    string TermsVersion,
    string PrivacyVersion,
    DateTime EffectiveUtc,
    string TermsUrl,
    string PrivacyUrl,
    bool RequiresLegalAcceptance);

public sealed class LegalPolicy(IConfiguration configuration)
{
    public const string DefaultVersion = "2026-07-20";

    public string TermsVersion => configuration["Legal:TermsVersion"] ?? DefaultVersion;
    public string PrivacyVersion => configuration["Legal:PrivacyVersion"] ?? DefaultVersion;
    public string TermsUrl => configuration["Legal:TermsUrl"] ?? "https://doctor.ranaze.com/terms.html";
    public string PrivacyUrl => configuration["Legal:PrivacyUrl"] ?? "https://doctor.ranaze.com/privacy.html";
    public DateTime EffectiveUtc => DateTime.TryParse(configuration["Legal:EffectiveUtc"], out var value)
        ? value.ToUniversalTime()
        : new DateTime(2026, 7, 20, 0, 0, 0, DateTimeKind.Utc);

    public bool IsCurrent(AuthUser user) =>
        user.TermsAcceptedVersion == TermsVersion && user.PrivacyAcceptedVersion == PrivacyVersion;

    public LegalPolicyStatus Status(AuthUser? user = null) => new(
        TermsVersion, PrivacyVersion, EffectiveUtc, TermsUrl, PrivacyUrl,
        user is not null && !IsCurrent(user));

    public void Accept(AuthUser user, string source, DateTime? acceptedUtc = null)
    {
        var timestamp = acceptedUtc ?? DateTime.UtcNow;
        user.LegalAcceptances ??= [];
        if (IsCurrent(user) && user.LegalAcceptances.Any(record =>
                record.TermsVersion == TermsVersion && record.PrivacyVersion == PrivacyVersion))
            return;
        user.TermsAcceptedVersion = TermsVersion;
        user.PrivacyAcceptedVersion = PrivacyVersion;
        user.LegalAcceptedUtc = timestamp;
        user.LegalAcceptances.Add(new LegalAcceptanceRecord
        {
            TermsVersion = TermsVersion,
            PrivacyVersion = PrivacyVersion,
            AcceptedUtc = timestamp,
            Source = source
        });
    }
}