package upstream

import (
	"strconv"
	"strings"
	"time"

	"codeberg.org/codeberg/pages/server/cache"
	"codeberg.org/codeberg/pages/server/gitea"
	"github.com/rs/zerolog/log"
)

type Redirect struct {
	From       string
	To         string
	StatusCode int
}

// redirectsCacheTimeout specifies the timeout for the redirects cache.
var redirectsCacheTimeout = 10 * time.Minute

const redirectsConfig = "_redirects"

// GetRedirects returns redirects specified in the _redirects file.
func (o *Options) GetRedirects(giteaClient *gitea.Client, redirectsCache cache.SetGetKey) []Redirect {
	var redirects []Redirect

	// Check for cached redirects
	if cachedValue, ok := redirectsCache.Get(o.TargetOwner + "/" + o.TargetRepo + "/" + o.TargetBranch); ok {
		redirects = cachedValue.([]Redirect)
	} else {
		// Get _redirects file and parse
		body, err := giteaClient.GiteaRawContent(o.TargetOwner, o.TargetRepo, o.TargetBranch, redirectsConfig)
		if err == nil {
			for _, line := range strings.Split(string(body), "\n") {
				redirectArr := strings.Fields(line)

				// Ignore comments and invalid lines
				if strings.HasPrefix(line, "#") || len(redirectArr) < 2 {
					continue
				}

				// Get redirect status code
				statusCode := 301
				if len(redirectArr) == 3 {
					statusCode, err = strconv.Atoi(redirectArr[2])
					if err != nil {
						log.Info().Err(err).Msgf("could not read %s of %s/%s", redirectsConfig, o.TargetOwner, o.TargetRepo)
					}
				}

				redirects = append(redirects, Redirect{
					From:       redirectArr[0],
					To:         redirectArr[1],
					StatusCode: statusCode,
				})
			}
		}
		_ = redirectsCache.Set(o.TargetOwner+"/"+o.TargetRepo+"/"+o.TargetBranch, redirects, redirectsCacheTimeout)
	}
	return redirects
}