package mining

import (
	"encoding/json"
	"io"
	"net/http"
	"strconv"
)

var (
	version = "dev"
	commit  = "none"
	date    = "unknown"
)

// versionString := mining.GetVersion() // "1.2.3" or "dev" when unset
func GetVersion() string {
	return version
}

// commitHash := mining.GetCommit() // "a1b2c3d" or "none" when unset
func GetCommit() string {
	return commit
}

// buildDate := mining.GetBuildDate() // "2026-04-02T00:00:00Z" or "unknown" when unset
func GetBuildDate() string {
	return date
}

// release := &GitHubRelease{TagName: "v6.21.0", Name: "XMRig v6.21.0"}
type GitHubRelease struct {
	TagName string `json:"tag_name"`
	Name    string `json:"name"`
}

// tag, err := FetchLatestGitHubVersion("xmrig", "xmrig") // "v6.21.0"
func FetchLatestGitHubVersion(owner, repo string) (string, error) {
	circuitBreaker := getGitHubCircuitBreaker()

	result, err := circuitBreaker.Execute(func() (interface{}, error) {
		return fetchGitHubVersionDirect(owner, repo)
	})

	if err != nil {
		// If circuit is open, try to return cached value with warning
		if err == ErrCircuitOpen {
			if cached, ok := circuitBreaker.GetCached(); ok {
				if tagName, ok := cached.(string); ok {
					return tagName, nil
				}
			}
			return "", ErrInternal("github API unavailable (circuit breaker open)").WithCause(err)
		}
		return "", err
	}

	tagName, ok := result.(string)
	if !ok {
		return "", ErrInternal("unexpected result type from circuit breaker")
	}

	return tagName, nil
}

// tag, err := fetchGitHubVersionDirect("xmrig", "xmrig") // "v6.21.0"; called via circuit breaker
func fetchGitHubVersionDirect(owner, repo string) (string, error) {
	url := "https://api.github.com/repos/" + owner + "/" + repo + "/releases/latest"

	resp, err := getHTTPClient().Get(url)
	if err != nil {
		return "", ErrInternal("failed to fetch version").WithCause(err)
	}
	defer resp.Body.Close()

	if resp.StatusCode != http.StatusOK {
		io.Copy(io.Discard, resp.Body) // Drain body to allow connection reuse
		return "", ErrInternal("failed to get latest release: unexpected status code " + strconv.Itoa(resp.StatusCode))
	}

	var release GitHubRelease
	if err := json.NewDecoder(resp.Body).Decode(&release); err != nil {
		return "", ErrInternal("failed to decode release").WithCause(err)
	}

	return release.TagName, nil
}