package task

import (
	"dsbqj-admin/model/mongo/version"
	"dsbqj-admin/pkg/util"
	"strings"
	"sync"

	"github.com/kamva/mgm/v3"
	"go.mongodb.org/mongo-driver/bson"
)

const (
	releaseEnvVersion = "release"
	trialEnvVersion   = "trial"
)

var VersionTask *Versions

type Versions struct {
	sync.Mutex
	VPlatforms util.SafeMap[string, *PlatformVersions]
}

type PlatformVersions struct {
	VList util.SafeArray[*version.Version]
	VMap  util.SafeMap[string, *version.Version]
}

func NormalizeEnvVersion(envVersion string) string {
	if strings.EqualFold(strings.TrimSpace(envVersion), trialEnvVersion) {
		return trialEnvVersion
	}
	return releaseEnvVersion
}

func VersionInit() *Versions {
	VersionTask = new(Versions)
	return VersionTask
}

func (this *Versions) Exec() {
	VersionConfigTask.Reload()
	var versions = make([]*version.Version, 0)
	err := mgm.Coll(&version.Version{}).SimpleFind(&versions, bson.M{})
	if err == nil {
		this.VPlatforms.Clear()
		for _, v := range versions {
			key := strings.TrimSpace(v.Platform)
			if _, ok := this.VPlatforms.Get(key); !ok {
				this.VPlatforms.Set(key, new(PlatformVersions))
			}

			platformVersions, _ := this.VPlatforms.Get(key)
			platformVersions.VList.Push(v)
			platformVersions.VMap.Set(versionMapKey(v.Version, NormalizeEnvVersion(v.EnvVersion)), v)
		}
	}
}

func (this *Versions) Check(version string, platform string, envVersion string) *version.Version {
	envVersionRequired := strings.TrimSpace(envVersion) != ""
	if strings.EqualFold(strings.TrimSpace(envVersion), "develop") {
		envVersion = trialEnvVersion
	}
	envVersion = NormalizeEnvVersion(envVersion)
	platform = strings.TrimSpace(platform)

	if result := this.checkPlatform(platform, version, envVersion, envVersionRequired); result != nil {
		return result
	}
	// Historical records did not carry platform. They remain a read-only fallback
	// until data is migrated, and never override platform-specific records.
	if platform != "" {
		if result := this.checkPlatform("", version, envVersion, envVersionRequired); result != nil {
			return result
		}
	}
	candidates := []string{platform}
	if platform != "" {
		candidates = append(candidates, "")
	}
	for _, candidate := range candidates {
		if result := this.checkPlatform(candidate, version, releaseEnvVersion, true); result != nil {
			return result
		}
		if result := this.checkPlatform(candidate, "", releaseEnvVersion, true); result != nil {
			return result
		}
	}
	return nil
}

func (this *Versions) checkPlatform(platform, version, envVersion string, envVersionRequired bool) *version.Version {
	platformVersions, ok := this.VPlatforms.Get(strings.TrimSpace(platform))
	if !ok {
		return nil
	}

	if strings.TrimSpace(version) == "" {
		return this.defaultVersion(platformVersions, envVersion)
	}

	if envVersionRequired {
		if data, ok := platformVersions.VMap.Get(versionMapKey(version, envVersion)); ok {
			return data
		}
		return this.defaultVersion(platformVersions, envVersion)
	}

	if data, ok := platformVersions.VMap.Get(versionMapKey(version, releaseEnvVersion)); ok {
		return data
	}
	if data, ok := platformVersions.VMap.Get(versionMapKey(version, trialEnvVersion)); ok {
		return data
	}
	return nil
}

func (this *Versions) defaultVersion(platformVersions *PlatformVersions, envVersion string) *version.Version {
	var fallback *version.Version
	var selected *version.Version
	for _, v := range platformVersions.VList.View() {
		if NormalizeEnvVersion(v.EnvVersion) != envVersion {
			continue
		}
		if fallback == nil || CompareConfigVersion(v.Version, fallback.Version) > 0 {
			fallback = v
		}
		if v.Default && (selected == nil || CompareConfigVersion(v.Version, selected.Version) > 0) {
			selected = v
		}
	}
	if selected != nil {
		return selected
	}
	return fallback
}

func versionMapKey(version string, envVersion string) string {
	return envVersion + ":" + version
}

func (this *Versions) Servers(platform string) []*version.Version {
	var res = make([]*version.Version, 0)
	if platformVersions, ok := this.VPlatforms.Get(strings.TrimSpace(platform)); ok {
		res = append(res, platformVersions.VList.View()...)
	}
	if len(res) == 0 && strings.TrimSpace(platform) != "" {
		if legacyVersions, ok := this.VPlatforms.Get(""); ok {
			res = append(res, legacyVersions.VList.View()...)
		}
	}
	return res
}