//! Write handlers — footnotes and endorsements.

use axum::{
    extract::Path,
    http::StatusCode,
    response::{IntoResponse, Redirect, Response},
    Form,
};

use crate::auth::MaybeUser;
use crate::AppState;

use super::super::{
    check_community_access, check_user_post_rate, check_write_access, get_community,
    parse_uuid, validate_body, FootnoteForm,
};
use super::posts::{resolve_and_render_mentions, MAX_FOOTNOTES_PER_POST};

// ============================================================================
// Footnote handler
// ============================================================================

#[tracing::instrument(skip_all)]
pub(in crate::routes) async fn add_footnote_handler(
    axum::extract::State(state): axum::extract::State<AppState>,
    Path((slug, category_slug, thread_id_str, post_id_str)): Path<(String, String, String, String)>,
    MaybeUser(session_user): MaybeUser,
    Form(form): Form<FootnoteForm>,
) -> Result<Redirect, Response> {
    let user = session_user
        .ok_or_else(|| Redirect::to("/auth/login").into_response())?;

    let post_id = parse_uuid(&post_id_str)?;

    let post_data = mt_db::queries::get_post_for_edit(&state.db, post_id)
        .await
        .map_err(|e| {
            tracing::error!(error = ?e, "db error fetching post for footnote");
            StatusCode::INTERNAL_SERVER_ERROR.into_response()
        })?
        .ok_or_else(|| StatusCode::NOT_FOUND.into_response())?;

    // Only the post author can add footnotes
    if user.user_id != post_data.author_id {
        return Err(StatusCode::FORBIDDEN.into_response());
    }

    // Cannot add footnotes to removed posts
    let removed: bool = sqlx::query_scalar("SELECT removed_at IS NOT NULL FROM posts WHERE id = $1")
        .bind(post_id)
        .fetch_one(&state.db)
        .await
        .map_err(|e| {
            tracing::error!(error = ?e, "db error checking removal status");
            StatusCode::INTERNAL_SERVER_ERROR.into_response()
        })?;
    if removed {
        return Err(StatusCode::FORBIDDEN.into_response());
    }

    // Cap footnotes per post
    let footnote_count = mt_db::queries::count_footnotes_for_post(&state.db, post_id)
        .await
        .map_err(|e| {
            tracing::error!(error = ?e, "db error counting footnotes");
            StatusCode::INTERNAL_SERVER_ERROR.into_response()
        })?;
    if footnote_count >= MAX_FOOTNOTES_PER_POST as i64 {
        return Err((
            StatusCode::UNPROCESSABLE_ENTITY,
            "Maximum footnotes reached for this post.",
        )
            .into_response());
    }

    // Check write access (suspension + ban + mute)
    let community = get_community(&state.db, &slug).await?;

    check_write_access(&state.db, community.id, user.user_id, community.suspended_at.is_some()).await?;
    mt_db::mutations::ensure_membership(&state.db, user.user_id, community.id)
        .await
        .map_err(|e| {
            tracing::error!(error = ?e, "db error ensuring membership");
            StatusCode::INTERNAL_SERVER_ERROR.into_response()
        })?;
    check_user_post_rate(&state.db, user.user_id).await?;

    let body = validate_body(&form.body, 65536, "Footnote")?;

    let (body_html, _mention_ids) = resolve_and_render_mentions(
        &state.db, body, community.id, &slug, user.user_id,
    ).await?;

    mt_db::mutations::insert_footnote(&state.db, post_id, user.user_id, body, &body_html)
        .await
        .map_err(|e| {
            tracing::error!(error = ?e, "db error inserting footnote");
            StatusCode::INTERNAL_SERVER_ERROR.into_response()
        })?;

    Ok(Redirect::to(&format!(
        "/p/{slug}/{category_slug}/{thread_id_str}?toast=Footnote+added"
    )))
}

// ============================================================================
// Endorsement handler
// ============================================================================

#[tracing::instrument(skip_all)]
pub(in crate::routes) async fn toggle_endorsement_handler(
    axum::extract::State(state): axum::extract::State<AppState>,
    Path((slug, category_slug, thread_id_str, post_id_str)): Path<(String, String, String, String)>,
    MaybeUser(session_user): MaybeUser,
) -> Result<Redirect, Response> {
    let user = session_user
        .ok_or_else(|| Redirect::to("/auth/login").into_response())?;

    let post_id = parse_uuid(&post_id_str)?;

    let post_data = mt_db::queries::get_post_for_edit(&state.db, post_id)
        .await
        .map_err(|e| {
            tracing::error!(error = ?e, "db error fetching post for endorsement");
            StatusCode::INTERNAL_SERVER_ERROR.into_response()
        })?
        .ok_or_else(|| StatusCode::NOT_FOUND.into_response())?;

    // Cannot endorse own post
    if user.user_id == post_data.author_id {
        return Err(StatusCode::FORBIDDEN.into_response());
    }

    // Cannot endorse a removed post
    let removed: bool = sqlx::query_scalar("SELECT removed_at IS NOT NULL FROM posts WHERE id = $1")
        .bind(post_id)
        .fetch_one(&state.db)
        .await
        .map_err(|e| {
            tracing::error!(error = ?e, "db error checking removal status");
            StatusCode::INTERNAL_SERVER_ERROR.into_response()
        })?;
    if removed {
        return Err(StatusCode::FORBIDDEN.into_response());
    }

    // Check community access (suspension + ban) — no mute check since endorsing is not content
    let community = get_community(&state.db, &slug).await?;
    check_community_access(&state.db, &community, Some(user.user_id)).await?;

    // Check platform suspension
    let suspended = mt_db::queries::is_user_suspended(&state.db, user.user_id)
        .await
        .map_err(|e| {
            tracing::error!(error = ?e, "db error checking user suspension");
            StatusCode::INTERNAL_SERVER_ERROR.into_response()
        })?;
    if suspended {
        return Err((StatusCode::FORBIDDEN, "Your account has been suspended.").into_response());
    }

    mt_db::mutations::toggle_endorsement(&state.db, post_id, user.user_id)
        .await
        .map_err(|e| {
            tracing::error!(error = ?e, "db error toggling endorsement");
            StatusCode::INTERNAL_SERVER_ERROR.into_response()
        })?;

    Ok(Redirect::to(&format!(
        "/p/{slug}/{category_slug}/{thread_id_str}#post-{post_id_str}"
    )))
}