//! Issue read-only views: list and detail.

use axum::{
    extract::{Path, Query, State},
    response::IntoResponse,
};
use serde::Deserialize;
use tower_sessions::Session;

use crate::{
    auth::MaybeUserVerified,
    db::{self, IssueStatus},
    error::{AppError, Result},
    helpers::get_csrf_token,
    templates::*,
    AppState,
};

use super::default_ref;

// ── Issue List ──

#[derive(Deserialize)]
pub(super) struct IssueListQuery {
    status: Option<String>,
    search: Option<String>,
    page: Option<i64>,
}

/// `GET /git/{owner}/{repo}/issues`
#[tracing::instrument(skip_all, name = "git_issues::list")]
pub(super) async fn issue_list(
    State(state): State<AppState>,
    session: Session,
    MaybeUserVerified(maybe_user): MaybeUserVerified,
    Path((owner, repo_name)): Path<(String, String)>,
    Query(query): Query<IssueListQuery>,
) -> Result<impl IntoResponse> {
    let resolved = super::resolve_repo(&state, &owner, &repo_name, maybe_user.as_ref().map(|u| u.id)).await?;

    let status_filter = match query.status.as_deref() {
        Some("closed") => Some(IssueStatus::Closed),
        _ => Some(IssueStatus::Open), // default to open
    };
    let current_status = query.status.as_deref().unwrap_or("open").to_string();
    let search = query.search.as_deref().filter(|s| !s.is_empty());
    // Upper-clamp page so `OFFSET = (page-1)*per_page` in list_issues can't
    // overflow i64 on a hostile `?page=` (1e9 pages × 25 is already 25B rows,
    // far past any real repo). Mirrors the admin user-list clamp.
    let page = query.page.unwrap_or(1).clamp(1, 1_000_000_000);
    let per_page = 25;

    let (issues, total) = db::issues::list_issues(
        &state.db, resolved.db_repo.id, status_filter, search, page, per_page,
    ).await?;

    let total_pages = (total + per_page - 1) / per_page;
    let (open_count, closed_count) = db::issues::get_issue_counts(&state.db, resolved.db_repo.id).await?;
    let current_ref = default_ref(&state, &owner, &repo_name);
    let csrf_token = get_csrf_token(&session).await;

    let is_owner = maybe_user.as_ref().map(|u| u.id) == Some(resolved.db_user.id);
    let email_address = format!("{}+{}@issues.makenot.work", owner, repo_name);

    Ok(GitIssueListTemplate {
        csrf_token,
        session_user: maybe_user,
        owner,
        repo_name,
        current_ref,
        issues,
        open_count,
        closed_count,
        current_status,
        search_query: query.search.unwrap_or_default(),
        current_page: page,
        total_pages,
        is_owner,
        email_address,
    })
}

// ── Issue Detail ──

/// `GET /git/{owner}/{repo}/issues/{number}`
#[tracing::instrument(skip_all, name = "git_issues::detail")]
pub(super) async fn issue_detail(
    State(state): State<AppState>,
    session: Session,
    MaybeUserVerified(maybe_user): MaybeUserVerified,
    Path((owner, repo_name, number)): Path<(String, String, i32)>,
) -> Result<impl IntoResponse> {
    let resolved = super::resolve_repo(&state, &owner, &repo_name, maybe_user.as_ref().map(|u| u.id)).await?;

    let issue = db::issues::get_issue_by_number(&state.db, resolved.db_repo.id, number)
        .await?
        .ok_or(AppError::NotFound)?;

    let author = db::users::get_user_by_id(&state.db, issue.author_user_id)
        .await?
        .ok_or(AppError::NotFound)?;

    let comments = db::issues::list_comments(&state.db, issue.id).await?;

    let is_owner = maybe_user.as_ref().map(|u| u.id) == Some(resolved.db_user.id);

    let (open_issue_count, _) = db::issues::get_issue_counts(&state.db, resolved.db_repo.id).await?;
    let current_ref = default_ref(&state, &owner, &repo_name);
    let csrf_token = get_csrf_token(&session).await;

    let email_address = format!("{}+{}@issues.makenot.work", owner, repo_name);

    Ok(GitIssueDetailTemplate {
        csrf_token,
        session_user: maybe_user,
        owner,
        repo_name,
        current_ref,
        issue,
        author_username: author.username.to_string(),
        comments,
        is_owner,
        open_issue_count,
        email_address,
    })
}