use crate::domain::entities::user::User;
use crate::domain::repositories::user_repository::UserListEntry;
use chrono::{DateTime, Utc};
use serde::{Deserialize, Serialize};
use smol_str::SmolStr;
use std::sync::Arc;
use utoipa::ToSchema;
use uuid::Uuid;

#[derive(Debug, Clone, Serialize, Deserialize, ToSchema)]
pub struct UserDto {
    pub id: String,
    /// Optional handle. `None` for users who have not claimed one
    /// (externals, fresh email-only signups). Frontend display callers
    /// should walk `username → given/family → email` as their fallback
    /// chain. Omitted from JSON when None (consistent with the existing
    /// given_name / family_name fields).
    #[serde(skip_serializing_if = "Option::is_none")]
    pub username: Option<String>,
    pub email: String,
    pub role: String,
    pub storage_quota_bytes: i64,
    pub storage_used_bytes: i64,
    pub created_at: DateTime<Utc>,
    pub updated_at: DateTime<Utc>,
    pub last_login_at: Option<DateTime<Utc>>,
    pub active: bool,
    pub auth_provider: String,
    pub image: Option<String>,
    pub can_edit_image: bool,
    /// `true` for grant-only external recipients (magic-link, OIDC-only,
    /// future OCM federated). External users have no home folder and
    /// can't own storage; their quota is always 0. Internal users
    /// default to `false`.
    pub is_external: bool,
    /// Optional first/given name. Populated from the OIDC `given_name`
    /// claim at JIT provisioning, or via a profile-edit endpoint.
    /// `None` until explicitly set — `skip_serializing_if = "Option::is_none"`
    /// keeps the wire format compact for the common case.
    #[serde(skip_serializing_if = "Option::is_none")]
    pub given_name: Option<String>,
    /// Optional last/family name. Same provenance + serde rules as
    /// `given_name`.
    #[serde(skip_serializing_if = "Option::is_none")]
    pub family_name: Option<String>,
    /// When the user first demonstrated control of their email (PR 23).
    /// `None` = unverified (omitted from JSON). Stamped on the first
    /// successful magic-link redemption or OIDC JIT with verified
    /// claim. Idempotent — the original timestamp is preserved on
    /// subsequent verifications.
    #[serde(skip_serializing_if = "Option::is_none")]
    pub email_verified_at: Option<DateTime<Utc>>,
    /// User-chosen locale for server-rendered surfaces (emails,
    /// future authenticated HTML). `None` = no preference (the server
    /// resolves to `OXICLOUD_DEFAULT_LOCALE` when rendering). Round-trips
    /// through `/api/auth/me` and `PATCH /api/auth/me/profile`.
    #[serde(skip_serializing_if = "Option::is_none")]
    pub preferred_locale: Option<String>,
    /// Whether the user wants an email when someone shares a resource
    /// with them. `true` (default) = receive share-notification mails;
    /// `false` = grants are still created but no email is sent. Honored
    /// only on the plain-notification path — magic-link first-invitations
    /// to brand-new external users always send, otherwise the recipient
    /// could never claim the share. Round-trips through `/api/auth/me`
    /// and `PATCH /api/auth/me/profile`.
    pub notify_on_share: bool,
    /// Opaque UI preferences bag. Cross-device store for pure UI
    /// toggles (hide dotfiles, view mode, sidebar collapse, …). The
    /// server never inspects the contents — this DTO field just echoes
    /// what was PATCHed via `PATCH /api/auth/me/profile`. Shape is a
    /// JSON object; the frontend defines the keys it cares about (see
    /// `frontend/src/lib/stores/preferences.svelte.ts`). Always present
    /// on the wire; empty bag is `{}`, never `null`.
    pub ui_preferences: serde_json::Value,
}

/// Compact row returned by the paginated admin user table.
///
/// Account-detail fields deliberately do not appear here.  In particular,
/// omitting `image` and `ui_preferences` prevents a 100-row page from turning
/// into tens of MiB when users have uploaded avatars.  `GET /api/admin/users/:id`
/// remains the full-detail endpoint.
#[derive(Debug, Clone, Serialize, Deserialize, ToSchema)]
pub struct AdminUserSummaryDto {
    pub id: String,
    #[serde(skip_serializing_if = "Option::is_none")]
    pub username: Option<String>,
    pub email: String,
    pub role: String,
    pub storage_quota_bytes: i64,
    pub storage_used_bytes: i64,
    pub last_login_at: Option<DateTime<Utc>>,
    pub active: bool,
    pub auth_provider: String,
    pub is_external: bool,
}

impl From<UserListEntry> for AdminUserSummaryDto {
    fn from(entry: UserListEntry) -> Self {
        Self {
            id: entry.id.to_string(),
            username: entry.username,
            email: entry.email,
            role: entry.role.to_string(),
            storage_quota_bytes: entry.storage_quota_bytes,
            storage_used_bytes: entry.storage_used_bytes,
            last_login_at: entry.last_login_at,
            active: entry.active,
            auth_provider: entry.oidc_provider.unwrap_or_else(|| "local".to_string()),
            is_external: entry.is_external,
        }
    }
}

impl From<User> for UserDto {
    fn from(user: User) -> Self {
        // `user` is owned and dropped here, so every owned field is MOVED out
        // via `into_parts` rather than cloned through the borrowing accessors —
        // the accessor form deep-cloned `image` (a data URI up to 512 KiB) and
        // the whole `ui_preferences` JSON tree on every `/api/auth/me` and admin
        // user listing (benches/ROUND20.md §A2). The two derived values read the
        // entity before the move.
        let role = format!("{}", user.role());
        let can_edit_image = !user.is_oidc_user();
        let p = user.into_parts();
        Self {
            id: p.id.to_string(),
            username: p.username,
            email: p.email,
            role,
            storage_quota_bytes: p.storage_quota_bytes,
            storage_used_bytes: p.storage_used_bytes,
            created_at: p.created_at,
            updated_at: p.updated_at,
            last_login_at: p.last_login_at,
            active: p.active,
            // Some(provider) moves the String; None still allocates "local".
            auth_provider: p.oidc_provider.unwrap_or_else(|| "local".to_string()),
            image: p.image,
            can_edit_image,
            is_external: p.is_external,
            given_name: p.given_name,
            family_name: p.family_name,
            email_verified_at: p.email_verified_at,
            preferred_locale: p.preferred_locale,
            notify_on_share: p.notify_on_share,
            ui_preferences: p.ui_preferences,
        }
    }
}

#[derive(Debug, Serialize, Deserialize, Clone, ToSchema)]
pub struct LoginDto {
    /// Identifier the user typed. Accepts BOTH a username (no `@`) and
    /// an email address (`@` present). The server dispatches on
    /// `@`-in-input: with `@` it looks up by email; without, by
    /// username. The two namespaces are provably disjoint (PR 16
    /// forbids `@` in usernames), so a single field handles both
    /// without ambiguity. The frontend submits whatever the user
    /// typed in the "Username or email" field as-is.
    pub username: String,
    pub password: String,
}

#[derive(Debug, Serialize, Deserialize, Clone, ToSchema)]
pub struct RegisterDto {
    /// Optional handle (2-64 chars, no `@`). When omitted, the user can
    /// claim one later via the profile-edit endpoint. Users without a
    /// username cannot use NextCloud clients or create app passwords
    /// (Basic-Auth resolves users by username); web UI / native API
    /// works fine without one.
    #[serde(default)]
    pub username: Option<String>,
    pub email: String,
    /// Optional password (≥8 chars when present). When omitted, a
    /// welcome magic-link is mailed to `email` for first-session
    /// bootstrap. The user can later set a password via the
    /// change-password endpoint to switch to classic username/email +
    /// password login.
    #[serde(default)]
    pub password: Option<String>,
}

/// DTO for the one-time initial admin setup endpoint (`/api/setup`).
/// Available only when the system is not yet initialized (no admin exists).
#[derive(Debug, Serialize, Deserialize, Clone, ToSchema)]
pub struct SetupAdminDto {
    pub username: String,
    pub email: String,
    pub password: String,
}

/// Partial-update body for `PATCH /api/auth/me/profile` (PR 24).
///
/// Each field is **optional**:
/// - **absent** → no change to that field.
/// - **present** → set / claim.
///
/// **Username is claim-once, immutable.** This endpoint accepts
/// `username` only when the caller currently has none — passing it
/// when one is already claimed is rejected with `409 UsernameImmutable`.
/// The immutability avoids the NextCloud / DAV client breakage that
/// would otherwise come from renaming (paths under
/// `/remote.php/dav/files/{user}/…` and the `verify_url_user` check
/// both bake the username in as a stable identifier). If a user really
/// typoed their handle and needs to fix it, an admin override is the
/// escape hatch.
///
/// **Given / family name** are freely settable. Any non-empty value
/// replaces the current one. Clearing back to `None` is out of scope
/// for v1.
///
/// **OIDC-linked users are rejected wholesale with 403** — their
/// profile fields are managed at the IdP. The IdP is the source of
/// truth; mirroring writes here would just create a divergence.
#[derive(Debug, Serialize, Deserialize, Clone, ToSchema, Default)]
pub struct UpdateProfileDto {
    /// Handle to claim (2-64 chars, `[A-Za-z0-9._-]+`, no `@`).
    /// Accepted only when the caller currently has no username. Once
    /// claimed the handle is permanent for the lifetime of the
    /// account; subsequent attempts to set or change it via this
    /// endpoint are rejected with 409. Admin override (via the
    /// admin-create-user / admin-update-user surface, future PR) is
    /// the escape hatch for genuine typos.
    #[serde(default)]
    pub username: Option<String>,
    /// New first/given name. Any non-empty value sets/replaces the
    /// current value. Absent → no change.
    #[serde(default)]
    pub given_name: Option<String>,
    /// New last/family name. Same semantics as `given_name`.
    #[serde(default)]
    pub family_name: Option<String>,
    /// New preferred locale (BCP-47 shape, e.g. `"fr"`, `"zh-TW"`).
    /// Must resolve against the server's `LocaleRegistry` — unknown
    /// codes are rejected with 400. Pass an empty string to clear the
    /// preference back to the server default (the application layer
    /// normalises `""` → `None`).
    #[serde(default)]
    pub preferred_locale: Option<String>,
    /// Whether to receive an email when someone shares a resource with
    /// the user. Absent → no change (existing setting preserved). Pass
    /// `true` to opt in, `false` to opt out. Honored only on the
    /// plain-notification path; magic-link first-invitations to externals
    /// always send.
    #[serde(default)]
    pub notify_on_share: Option<bool>,
    /// Partial patch into the opaque UI preferences bag. **Must be a
    /// JSON object.** Applied via a SHALLOW merge on the server:
    /// keys present here overwrite existing top-level keys; keys not
    /// present survive. A key value of `null` REMOVES that key from
    /// the bag (implemented via `jsonb_strip_nulls` after the merge).
    ///
    /// Example: current bag `{"a":1,"b":2}`, patch `{"b":3,"c":4}`
    /// → merged `{"a":1,"b":3,"c":4}`. Patch `{"a":null}` → `{"b":2}`.
    ///
    /// Absent → no change to the bag. This is a UI-only surface;
    /// server never inspects the keys.
    #[serde(default)]
    pub ui_preferences: Option<serde_json::Value>,
}

#[derive(Debug, Clone, Serialize, Deserialize, ToSchema)]
pub struct AuthResponseDto {
    pub user: UserDto,
    pub access_token: String,
    pub refresh_token: String,
    pub token_type: String,
    pub expires_in: i64,
}

#[derive(Debug, Serialize, Deserialize, ToSchema)]
pub struct ChangePasswordDto {
    pub current_password: String,
    pub new_password: String,
}

#[derive(Debug, Serialize, Deserialize, ToSchema)]
pub struct RefreshTokenDto {
    pub refresh_token: String,
}

/// Body for `POST /api/auth/upgrade-to-internal`. Converts an
/// authenticated external user into an internal user with their own
/// personal drive.
///
/// `password` is optional — semantics decided per deployment:
///   * If `magic_link` is in `OXICLOUD_AUTH_METHODS` (and OIDC isn't
///     enabled) → password can be omitted; user remains magic-link-only
///     for login after upgrade.
///   * Otherwise → password is required; refusal returns 400
///     `error_type = "PasswordRequired"`. Without it the upgraded user
///     would have no login path.
#[derive(Debug, Serialize, Deserialize, ToSchema)]
pub struct UpgradeToInternalDto {
    #[serde(default)]
    pub password: Option<String>,
}

/// Authenticated current user data (for use in application services)
///
/// Built once per authenticated request in the auth middlewares.
/// `username`/`email` are `Arc<str>` (refcount-bump clones from the cached
/// `TokenClaims` / Basic-auth cache — JSON shape unchanged) and `role` is an
/// inline `SmolStr` ("admin"/"user" fit the 23-byte inline buffer, so the
/// per-request live-role render allocates nothing).
#[derive(Clone, Debug, Serialize, Deserialize, ToSchema)]
pub struct CurrentUser {
    pub id: Uuid,
    #[schema(value_type = String)]
    pub username: Arc<str>,
    #[schema(value_type = String)]
    pub email: Arc<str>,
    #[schema(value_type = String)]
    pub role: SmolStr,
}

// ============================================================================
// App Password DTOs
// ============================================================================

#[derive(Debug, Serialize, Deserialize, ToSchema)]
pub struct CreateAppPasswordDto {
    pub label: String,
}

#[derive(Debug, Serialize, Deserialize, ToSchema)]
pub struct AppPasswordCreatedDto {
    pub id: String,
    pub label: String,
    pub password: String,
}

#[derive(Debug, Serialize, Deserialize, ToSchema)]
pub struct AppPasswordDto {
    pub id: String,
    pub label: String,
    pub created_at: DateTime<Utc>,
    pub last_used_at: Option<DateTime<Utc>>,
}

// ============================================================================
// OIDC DTOs
// ============================================================================

/// Response with the OIDC authorization URL for client redirect
#[derive(Debug, Serialize, Deserialize, ToSchema)]
pub struct OidcAuthorizeResponseDto {
    pub authorize_url: String,
    pub state: String,
}

/// Query parameters received on the OIDC callback
#[derive(Debug, Serialize, Deserialize, ToSchema)]
pub struct OidcCallbackQueryDto {
    pub code: String,
    pub state: String,
}

/// Request body for the OIDC one-time code exchange endpoint
#[derive(Debug, Serialize, Deserialize, ToSchema)]
pub struct OidcExchangeDto {
    pub code: String,
}

/// Information about available OIDC providers + self-service auth
/// methods enabled on the deployment. Consumed by the login page to
/// decide which forms/buttons to render.
#[derive(Debug, Serialize, Deserialize, ToSchema)]
pub struct OidcProviderInfoDto {
    pub enabled: bool,
    pub provider_name: String,
    pub authorize_endpoint: String,
    pub password_login_enabled: bool,
    /// True iff the server accepts magic-link login requests
    /// (`OXICLOUD_AUTH_METHODS` includes `magic_link` AND SMTP is
    /// configured). Frontend renders the magic-link form when true.
    #[serde(default)]
    pub magic_link_login_enabled: bool,
    /// True iff `OXICLOUD_REQUIRE_VERIFIED_EMAIL` is set. Frontend uses
    /// this hint to explain the `EmailNotVerified` login response and
    /// to nudge new users toward the magic-link verification path
    /// straight after signup.
    #[serde(default)]
    pub require_verified_email: bool,
}

/// Claims extracted from the validated OIDC ID token
#[derive(Debug, Clone, Serialize, Deserialize, ToSchema)]
pub struct OidcUserInfoDto {
    pub sub: String,
    pub preferred_username: Option<String>,
    pub email: Option<String>,
    pub name: Option<String>,
    pub groups: Vec<String>,
}