//! Forum article CRUD operations on `MessageRepo`.
//!
//! Articles extend regular messages with forum-specific metadata (title, cover,
//! view/like stats, tags). Rendered as waterfall cards in forum channels.

use chrono::Utc;
use sqlx::Row;
use uuid::Uuid;

use crate::ImksResult;
use crate::models::message::AuthorInfo;
use crate::models::message_article::{ArticleCard, ArticleSort, MessageArticle};

use super::message_repo::MessageRepo;
use super::pagination::{CursorPage, clamp_limit};

impl MessageRepo {
    /// Create an article record linked to an existing message.
    #[allow(clippy::too_many_arguments)]
    pub async fn create_article(
        &self,
        message_id: Uuid,
        title: &str,
        summary: Option<&str>,
        cover_url: Option<&str>,
        cover_width: Option<i32>,
        cover_height: Option<i32>,
        cover_color: Option<&str>,
        tags: Option<&serde_json::Value>,
    ) -> ImksResult<MessageArticle> {
        let id = Uuid::now_v7();
        let now = Utc::now();

        sqlx::query_as::<_, MessageArticle>(
            r#"
            INSERT INTO message_article (
                id, message_id, title, summary, cover_url, cover_width, cover_height,
                cover_color, tags, view_count, like_count, bookmark_count, reply_count,
                is_pinned_to_top, is_answered, created_at, updated_at
            ) VALUES ($1, $2, $3, $4, $5, $6, $7, $8, $9, 0, 0, 0, 0, FALSE, FALSE, $10, $10)
            RETURNING *
            "#,
        )
        .bind(id)
        .bind(message_id)
        .bind(title)
        .bind(summary)
        .bind(cover_url)
        .bind(cover_width)
        .bind(cover_height)
        .bind(cover_color)
        .bind(tags)
        .bind(now)
        .fetch_one(self.pool())
        .await
        .map_err(Into::into)
    }

    /// Update an existing article's metadata. Does NOT update the message body.
    pub async fn update_article(
        &self,
        message_id: Uuid,
        title: Option<&str>,
        summary: Option<&str>,
        cover_url: Option<&str>,
        cover_color: Option<&str>,
        tags: Option<&serde_json::Value>,
    ) -> ImksResult<Option<MessageArticle>> {
        let now = Utc::now();
        sqlx::query_as::<_, MessageArticle>(
            r#"
            UPDATE message_article
            SET title = COALESCE($1, title),
                summary = COALESCE($2, summary),
                cover_url = COALESCE($3, cover_url),
                cover_color = COALESCE($4, cover_color),
                tags = COALESCE($5, tags),
                updated_at = $6
            WHERE message_id = $7
            RETURNING *
            "#,
        )
        .bind(title)
        .bind(summary)
        .bind(cover_url)
        .bind(cover_color)
        .bind(tags)
        .bind(now)
        .bind(message_id)
        .fetch_optional(self.pool())
        .await
        .map_err(Into::into)
    }

    /// Get an article by its message_id.
    pub async fn get_article(&self, message_id: Uuid) -> ImksResult<Option<MessageArticle>> {
        sqlx::query_as::<_, MessageArticle>("SELECT * FROM message_article WHERE message_id = $1")
            .bind(message_id)
            .fetch_optional(self.pool())
            .await
            .map_err(Into::into)
    }

    /// List articles in a forum channel with id-based cursor pagination.
    pub async fn list_articles(
        &self,
        channel_id: Uuid,
        sort: ArticleSort,
        before: Option<(i64, Uuid)>,
        limit: Option<i64>,
    ) -> ImksResult<CursorPage<ArticleCard>> {
        let effective_limit = clamp_limit(limit);
        let fetch_limit = effective_limit + 1;
        let cursor_id = before.map(|(_, id)| id);

        let order_by = match sort {
            ArticleSort::LatestActivity => "a.last_reply_at DESC NULLS LAST, m.id DESC",
            ArticleSort::Newest => "m.id DESC",
            ArticleSort::MostViewed => "a.view_count DESC, m.id DESC",
            ArticleSort::MostLiked => "a.like_count DESC, m.id DESC",
            ArticleSort::PinnedFirst => {
                "a.is_pinned_to_top DESC, a.last_reply_at DESC NULLS LAST, m.id DESC"
            }
        };

        let query = if cursor_id.is_some() {
            format!(
                r#"
                SELECT a.*, m.author_id,
                       (
                           SELECT att.url
                           FROM message_attachment att
                           WHERE att.message_id = a.message_id
                             AND att.content_type LIKE 'image/%'
                           ORDER BY att.created_at
                           LIMIT 1
                       ) AS first_image_url
                FROM message_article a
                JOIN message m ON m.id = a.message_id
                WHERE m.channel_id = $1
                  AND m.deleted_at IS NULL
                  AND m.id < $2
                ORDER BY {order_by}
                LIMIT $3
                "#,
            )
        } else {
            format!(
                r#"
                SELECT a.*, m.author_id,
                       (
                           SELECT att.url
                           FROM message_attachment att
                           WHERE att.message_id = a.message_id
                             AND att.content_type LIKE 'image/%'
                           ORDER BY att.created_at
                           LIMIT 1
                       ) AS first_image_url
                FROM message_article a
                JOIN message m ON m.id = a.message_id
                WHERE m.channel_id = $1
                  AND m.deleted_at IS NULL
                ORDER BY {order_by}
                LIMIT $2
                "#,
            )
        };

        let rows = if let Some(cursor) = cursor_id {
            sqlx::query(sqlx::AssertSqlSafe(query.as_str()))
                .bind(channel_id)
                .bind(cursor)
                .bind(fetch_limit)
                .fetch_all(self.pool())
                .await?
        } else {
            sqlx::query(sqlx::AssertSqlSafe(query.as_str()))
                .bind(channel_id)
                .bind(fetch_limit)
                .fetch_all(self.pool())
                .await?
        };

        // Convert raw rows to MessageArticle
        let articles: Vec<MessageArticle> = rows
            .iter()
            .map(|r| MessageArticle {
                id: r.get("id"),
                message_id: r.get("message_id"),
                title: r.get("title"),
                summary: r.get("summary"),
                cover_url: r.get("cover_url"),
                cover_width: r.get("cover_width"),
                cover_height: r.get("cover_height"),
                cover_color: r.get("cover_color"),
                tags: r.get("tags"),
                view_count: r.get("view_count"),
                like_count: r.get("like_count"),
                bookmark_count: r.get("bookmark_count"),
                reply_count: r.get("reply_count"),
                last_reply_message_id: r.get("last_reply_message_id"),
                last_reply_at: r.get("last_reply_at"),
                last_reply_user_id: r.get("last_reply_user_id"),
                is_pinned_to_top: r.get("is_pinned_to_top"),
                is_answered: r.get("is_answered"),
                answered_by: r.get("answered_by"),
                answered_at: r.get("answered_at"),
                created_at: r.get("created_at"),
                updated_at: r.get("updated_at"),
            })
            .collect();

        let has_more = articles.len() > effective_limit as usize;
        let items: Vec<MessageArticle> = articles
            .into_iter()
            .take(effective_limit as usize)
            .collect();

        let next_cursor = if has_more {
            items.last().map(|a| a.message_id)
        } else {
            None
        };

        let cards: Vec<ArticleCard> = items
            .into_iter()
            .zip(rows.iter())
            .map(|(article, row)| {
                let author_id: Uuid = row.get("author_id");
                ArticleCard {
                    article,
                    author: AuthorInfo {
                        id: author_id,
                        username: author_id.to_string(),
                        display_name: None,
                        avatar_url: None,
                        is_bot: false,
                    },
                    tag_names: Vec::new(),
                    first_image_url: row.get("first_image_url"),
                    bookmarked: false,
                    liked: false,
                }
            })
            .collect();

        Ok(CursorPage {
            items: cards,
            next_cursor,
            has_more,
        })
    }

    /// Increment the view count for an article.
    pub async fn increment_article_view(&self, message_id: Uuid) -> ImksResult<()> {
        sqlx::query("UPDATE message_article SET view_count = view_count + 1 WHERE message_id = $1")
            .bind(message_id)
            .execute(self.pool())
            .await?;

        Ok(())
    }
}