//! Per-user account settings (signature + Fan+ status display).
//!
//! All routes require a logged-in session. The signature editor is gated on
//! [`UserPerks::effective_plus`]: non-Fan+ users see the upsell instead of an
//! input. Lapsed Fan+ users retain their saved markdown (we don't auto-delete
//! it) but the post-rendering layer hides their signature until they renew.

use axum::{
    extract::{Form, State},
    http::StatusCode,
    response::{IntoResponse, Redirect, Response},
};
use tower_sessions::Session;

use crate::AppState;
use crate::auth::RequireUser;
use crate::csrf;
use crate::templates::AccountSettingsTemplate;

use super::{
    SignatureForm, db_error, field_error, render_markdown, render_markdown_plus, template_user,
};

const SIGNATURE_MAX: usize = 1024;

#[tracing::instrument(skip_all)]
pub(super) async fn account_settings(
    State(state): State<AppState>,
    session: Session,
    RequireUser(user): RequireUser,
) -> Result<AccountSettingsTemplate, Response> {
    let csrf_token = Some(csrf::get_or_create_token(&session).await?);
    let (signature_markdown, signature_html) =
        mt_db::queries::get_user_signature(&state.db, user.user_id)
            .await
            .map_err(db_error)?
            .unwrap_or((None, None));

    Ok(AccountSettingsTemplate {
        csrf_token,
        session_user: Some(template_user(&user, state.config.platform_admin_id)),
        mnw_base_url: state.config.mnw_base_url.clone(),
        has_plus: user.perks.effective_plus(),
        fan_plus: user.perks.fan_plus,
        signature_markdown,
        signature_html,
    })
}

#[tracing::instrument(skip_all)]
pub(super) async fn update_signature_handler(
    State(state): State<AppState>,
    RequireUser(user): RequireUser,
    Form(form): Form<SignatureForm>,
) -> Result<Redirect, Response> {
    if !user.perks.effective_plus() {
        return Err((StatusCode::FORBIDDEN, "Signatures are a Fan+ feature.").into_response());
    }

    // "Clear signature" button submits with `clear=1`; takes precedence over
    // the textarea content.
    if form.clear.as_deref() == Some("1") {
        mt_db::mutations::clear_user_signature(&state.db, user.user_id)
            .await
            .map_err(db_error)?;
        return Ok(Redirect::to("/account?toast=Signature+cleared"));
    }

    let trimmed = form.signature.trim();
    if trimmed.is_empty() {
        // Treat empty submit as a no-op rather than implicit clear, there's
        // an explicit Clear button for that.
        return Ok(Redirect::to("/account"));
    }
    if trimmed.chars().count() > SIGNATURE_MAX {
        return Err(field_error(
            "signature",
            format!("Signature must be at most {SIGNATURE_MAX} characters."),
        ));
    }

    // Render with the same plus-aware paths as posts: creators get image
    // embeds via auto-grant, matching post-body behaviour. Render-time
    // visibility is gated by `users.is_fan_plus` so creator signatures
    // still only surface when they're also a Fan+ subscriber, auto-grant
    // covers editing capability, not the public + badge / signature display.
    let signature_html = if user.perks.effective_plus() {
        render_markdown_plus(trimmed)
    } else {
        render_markdown(trimmed)
    };

    mt_db::mutations::set_user_signature(&state.db, user.user_id, trimmed, &signature_html)
        .await
        .map_err(db_error)?;

    Ok(Redirect::to("/account?toast=Signature+saved"))
}