package version

import (
	"runtime/debug"
	"strconv"
	"time"
)

// These will be set by ldflags at build time
var (
	Version    = "dev"
	Commit     = ""
	BuildTime  = "0"
	IsModified = "false"
)

type VersionInfo struct {
	BuildTime  time.Time `json:"build_time"`
	IsModified bool      `json:"is_modified"`
	Revision   string    `json:"revision"`
}

func Get() VersionInfo {
	// Try ldflags first (set by Nix build)
	if Commit != "" && Commit != "unknown" {
		var buildTime time.Time
		if timestamp, err := strconv.ParseInt(BuildTime, 10, 64); err == nil && timestamp > 0 {
			buildTime = time.Unix(timestamp, 0)
		}

		return VersionInfo{
			Revision:   Commit,
			BuildTime:  buildTime,
			IsModified: IsModified == "true",
		}
	}

	// Fallback to debug.ReadBuildInfo() for development
	info, ok := debug.ReadBuildInfo()
	if !ok {
		return VersionInfo{
			Revision: "unknown",
		}
	}

	var version VersionInfo
	for _, setting := range info.Settings {
		switch setting.Key {
		case "vcs.modified":
			version.IsModified = setting.Value == "true"
		case "vcs.revision":
			if len(setting.Value) > 7 {
				version.Revision = setting.Value[:7]
			} else {
				version.Revision = setting.Value
			}
		case "vcs.time":
			if t, err := time.Parse(time.RFC3339, setting.Value); err == nil {
				version.BuildTime = t
			}
		}
	}

	return version
}