// Back - An extremely simple git bug visualization system. Inspired by TVL's
// panettone.
//
// Copyright (C) 2025 Benedikt Peetz <benedikt.peetz@b-peetz.de>
// SPDX-License-Identifier: AGPL-3.0-or-later
//
// This file is part of Back.
//
// You should have received a copy of the License along with this program.
// If not, see <https://www.gnu.org/licenses/agpl.txt>.

use std::convert::Infallible;

use bytes::Bytes;
use git_bug::replica::entity::id::prefix::IdPrefix;
use http::{Response, StatusCode, Version};
use http_body_util::{BodyExt, Full, combinators::BoxBody};
use vy::{IntoHtml, h1, p, pre};

use super::generate::templates::make_page;
use crate::error;

pub(super) fn html_response<T: Into<Bytes>>(html_text: T) -> Response<BoxBody<Bytes, Infallible>> {
    html_response_status(html_text, StatusCode::OK)
}

pub(super) fn html_response_status<T: Into<Bytes>>(
    html_text: T,
    status: StatusCode,
) -> Response<BoxBody<Bytes, Infallible>> {
    html_response_status_content_type(html_text, status, "text/html")
}

pub(super) fn redirect(target: &str) -> Response<BoxBody<Bytes, Infallible>> {
    Response::builder()
        .status(StatusCode::MOVED_PERMANENTLY)
        .version(Version::HTTP_2)
        .header("Location", target)
        .body(full(""))
        .expect("This is hardcoded and will build")
}

pub(super) fn html_response_status_content_type<T: Into<Bytes>>(
    html_text: T,
    status: StatusCode,
    content_type: &str,
) -> Response<BoxBody<Bytes, Infallible>> {
    Response::builder()
        .status(status)
        .version(Version::HTTP_2)
        .header("Content-Type", format!("{content_type}; charset=utf-8"))
        .header("x-content-type-options", "nosniff")
        .header("x-frame-options", "SAMEORIGIN")
        .body(full(html_text))
        .expect("This will always build")
}

pub(super) fn full<T: Into<Bytes>>(chunk: T) -> BoxBody<Bytes, Infallible> {
    Full::new(chunk.into()).boxed()
}

impl error::Error {
    #[allow(clippy::too_many_lines)]
    pub fn into_response(self) -> Response<BoxBody<Bytes, Infallible>> {
        log::error!("{self}");

        match self {
            error::Error::ConfigParse { .. }
            | error::Error::ProjectListRead { .. }
            | error::Error::ConfigRead { .. }
            | error::Error::RepoGetReferences(_)
            | error::Error::RepoIssueRead(_)
            | error::Error::RepoIdentityRead(_)
            | error::Error::RepoFind { .. }
            | error::Error::RepoRefsIter(_)
            | error::Error::RepoRefsPrefixed { .. }
            | error::Error::TcpBind { .. }
            | error::Error::RepoOpen { .. }
            | error::Error::TcpAccept { .. } => html_response_status(
                make_page(
                    (
                        h1!("Internal server error"),
                        pre!(format!("Error {}", self.to_string())),
                    ),
                    "Error page",
                    Some("Error | Back"),
                )
                .into_string(),
                StatusCode::INTERNAL_SERVER_ERROR,
            ),
            error::Error::NotGitBug { path } => html_response_status(
                make_page(
                    (
                        h1!("Expectation Failed"),
                        p!(
                            "Repository '",
                            path.display().to_string(),
                            "' has no git bug data to show."
                        ),
                    ),
                    "Error page",
                    Some("Error | Back"),
                )
                .into_string(),
                StatusCode::EXPECTATION_FAILED,
            ),
            error::Error::IssuesPrefixMissing { prefix, err } => html_response_status(
                make_page(
                    (
                        h1!("Expectation Failed"),
                        p!(
                            "There is no issue associated with the prefix ",
                            "'",
                            prefix.to_string(),
                            "': ",
                            err.to_string()
                        ),
                    ),
                    "Error page",
                    Some("Error | Back"),
                )
                .into_string(),
                StatusCode::EXPECTATION_FAILED,
            ),
            error::Error::IssuesPrefixParse { prefix, error } => html_response_status(
                make_page(
                    (
                        h1!("Expectation Failed"),
                        p!(
                            "The prefix '",
                            prefix,
                            "' cannot be interperted as a prefix",
                        ),
                        p!(error.to_string()),
                        p!(
                            "The prefix is composed of  ",
                            IdPrefix::REQUIRED_LENGTH,
                            " or more hex chars."
                        ),
                    ),
                    "Error page",
                    Some("Error | Back"),
                )
                .into_string(),
                StatusCode::EXPECTATION_FAILED,
            ),
            error::Error::NotFound(path_buf) => html_response_status(
                make_page(
                    (
                        h1!("Expectation Failed"),
                        p!(
                            "The path '",
                            path_buf.display().to_string(),
                            "' was unkonwn",
                        ),
                    ),
                    "Error page",
                    Some("Error | Back"),
                )
                .into_string(),
                StatusCode::EXPECTATION_FAILED,
            ),
            error::Error::InvalidQuery { err, query } => html_response_status(
                make_page(
                    (
                        h1!("Expectation Failed"),
                        p!("The query '", query, "' was invalid",),
                        p!(err.to_string()),
                    ),
                    "Error page",
                    Some("Error | Back"),
                )
                .into_string(),
                StatusCode::EXPECTATION_FAILED,
            ),
        }
    }
}