use crate::error::AppError;
use crate::models::wiki::WikiPageRevision;
use crate::service::RepoService;
use crate::session::Session;

use super::util::clamp_limit_offset;

impl RepoService {
    /// 获取页面的修订历史
    pub async fn wiki_get_revisions(
        &self,
        ctx: &Session,
        wk_name: &str,
        repo_name: &str,
        slug: &str,
        limit: i64,
        offset: i64,
    ) -> Result<Vec<WikiPageRevision>, AppError> {
        let user_uid = ctx.user().ok_or(AppError::Unauthorized)?;
        let page = self.wiki_get_page(ctx, wk_name, repo_name, slug).await?;
        self.ensure_repo_readable(user_uid, &self.resolve_repo(wk_name, repo_name).await?)
            .await?;
        let (limit, offset) = clamp_limit_offset(limit, offset);

        sqlx::query_as::<_, WikiPageRevision>(
            "SELECT id, page_id, version, title, content, editor_id, commit_message, created_at \
             FROM wiki_page_revision WHERE page_id = $1 ORDER BY version DESC LIMIT $2 OFFSET $3",
        )
        .bind(page.id)
        .bind(limit)
        .bind(offset)
        .fetch_all(self.ctx.db.reader())
        .await
        .map_err(AppError::Database)
    }

    /// 获取特定版本的修订详情
    pub async fn wiki_get_revision(
        &self,
        ctx: &Session,
        wk_name: &str,
        repo_name: &str,
        slug: &str,
        version: i32,
    ) -> Result<WikiPageRevision, AppError> {
        let user_uid = ctx.user().ok_or(AppError::Unauthorized)?;
        let page = self.wiki_get_page(ctx, wk_name, repo_name, slug).await?;
        self.ensure_repo_readable(user_uid, &self.resolve_repo(wk_name, repo_name).await?)
            .await?;

        sqlx::query_as::<_, WikiPageRevision>(
            "SELECT id, page_id, version, title, content, editor_id, commit_message, created_at \
             FROM wiki_page_revision WHERE page_id = $1 AND version = $2",
        )
        .bind(page.id)
        .bind(version)
        .fetch_optional(self.ctx.db.reader())
        .await
        .map_err(AppError::Database)?
        .ok_or_else(|| AppError::NotFound("Revision not found".into()))
    }

    /// 比较两个版本的差异
    pub async fn wiki_compare_revisions(
        &self,
        ctx: &Session,
        wk_name: &str,
        repo_name: &str,
        slug: &str,
        old_version: i32,
        new_version: i32,
    ) -> Result<(WikiPageRevision, WikiPageRevision), AppError> {
        let old = self
            .wiki_get_revision(ctx, wk_name, repo_name, slug, old_version)
            .await?;
        let new = self
            .wiki_get_revision(ctx, wk_name, repo_name, slug, new_version)
            .await?;
        Ok((old, new))
    }
}