package services

import (
	"context"
	"fmt"
	"os"
	"os/exec"
	"strings"

	"opsxloki/models"
)

// CollectorDeployer 采集器部署器，按 type 分发到三种安装/卸载流程
type CollectorDeployer struct {
	collector *models.Collector
	loki      *models.LokiDeployment
	logFunc   func(level, message, detail string)
}

func NewCollectorDeployer(c *models.Collector, l *models.LokiDeployment, logFunc func(level, message, detail string)) *CollectorDeployer {
	return &CollectorDeployer{collector: c, loki: l, logFunc: logFunc}
}

func (d *CollectorDeployer) log(level, message, detail string) {
	if d.logFunc != nil {
		d.logFunc(level, message, detail)
	}
}

// kubeconfigEnv 构造 kubectl/helm 所需的 KUBECONFIG 环境变量，返回 cleanup 删除临时文件
func kubeconfigEnv(cluster *models.Cluster) (env []string, cleanup func(), err error) {
	kubeconfig, err := resolveKubeconfig(cluster)
	if err != nil {
		return nil, nil, err
	}
	kubeFile, err := os.CreateTemp("", "kube-*.yaml")
	if err != nil {
		return nil, nil, fmt.Errorf("create kubeconfig temp file failed: %w", err)
	}
	if _, err := kubeFile.WriteString(kubeconfig); err != nil {
		kubeFile.Close()
		os.Remove(kubeFile.Name())
		return nil, nil, fmt.Errorf("write kubeconfig temp file failed: %w", err)
	}
	kubeFile.Close()
	os.Chmod(kubeFile.Name(), 0600)
	env = append(os.Environ(), fmt.Sprintf("KUBECONFIG=%s", kubeFile.Name()))
	cleanup = func() { os.Remove(kubeFile.Name()) }
	return env, cleanup, nil
}

// Install 按采集器类型分发安装
func (d *CollectorDeployer) Install(ctx context.Context) error {
	endpoint := d.loki.Endpoint
	if endpoint == "" {
		return fmt.Errorf("关联的 Loki 尚未部署，缺少推送地址（endpoint），请先成功部署该 Loki")
	}
	d.log("info", fmt.Sprintf("开始部署采集器 %s（类型 %s）", d.collector.Name, d.collector.Type), "")

	var err error
	switch d.collector.Type {
	case "host-promtail":
		err = d.installHost(ctx, endpoint)
	case "k8s-daemonset":
		err = d.installDaemonset(ctx, endpoint)
	case "k8s-fluentbit-sidecar":
		err = d.installSidecar(ctx, endpoint)
	default:
		return fmt.Errorf("不支持的采集器类型: %s", d.collector.Type)
	}
	if err != nil {
		d.log("error", fmt.Sprintf("采集器部署失败: %v", err), "")
		return err
	}
	d.log("success", "采集器部署完成", "")
	return nil
}

// Uninstall 按采集器类型分发卸载
func (d *CollectorDeployer) Uninstall(ctx context.Context) error {
	d.log("info", fmt.Sprintf("开始卸载采集器 %s（类型 %s）", d.collector.Name, d.collector.Type), "")
	switch d.collector.Type {
	case "host-promtail":
		return d.uninstallHost(ctx)
	case "k8s-daemonset":
		return d.uninstallDaemonset(ctx)
	case "k8s-fluentbit-sidecar":
		return d.uninstallSidecar(ctx)
	}
	return nil
}

// ===== host-promtail：SSH 安装 Promtail 二进制 + systemd =====

func (d *CollectorDeployer) installHost(ctx context.Context, endpoint string) error {
	host := d.collector.Host
	if host == nil {
		return fmt.Errorf("主机采集器缺少目标主机")
	}
	client, err := NewSSHClientWithAuth(HostSSHAuth(host))
	if err != nil {
		return err
	}
	defer client.Close()

	// 检测架构
	archOut, _, _ := client.Execute(ctx, "uname -m")
	arch := strings.TrimSpace(archOut)
	switch arch {
	case "x86_64":
		arch = "amd64"
	case "aarch64", "arm64":
		arch = "arm64"
	default:
		return fmt.Errorf("不支持的主机架构: %s", arch)
	}

	// 确定 Promtail 版本（优先使用关联的 Loki 版本）
	version := "3.0.0"
	if d.loki != nil && d.loki.Version != "" {
		version = d.loki.Version
	}

	// 创建必要目录
	d.log("info", "准备目录 /opt/promtail /etc/promtail /var/lib/promtail", "")
	if _, _, err := client.Execute(ctx, "mkdir -p /opt/promtail /etc/promtail /var/lib/promtail"); err != nil {
		return fmt.Errorf("创建 Promtail 目录失败: %w", err)
	}

	// 下载 Promtail
	d.log("info", fmt.Sprintf("下载 Promtail %s（%s）", version, arch), "")
	url := fmt.Sprintf("https://github.com/grafana/loki/releases/download/v%s/promtail-linux-%s.zip", version, arch)
	dl := fmt.Sprintf("cd /tmp && curl -fsSL -o p.zip '%s' && unzip -o p.zip -d /opt/promtail/ && chmod +x /opt/promtail/promtail-linux-%s", url, arch)
	if _, _, err := client.Execute(ctx, dl); err != nil {
		return fmt.Errorf("下载 Promtail 失败: %w", err)
	}
	client.Execute(ctx, "ln -sf /opt/promtail/promtail-linux-* /usr/local/bin/promtail 2>/dev/null || true")

	// 生成并上传配置
	logPath := d.collector.LogPath
	if logPath == "" {
		logPath = "/var/log/*.log"
	}
	conf := PromtailConfig(endpoint, logPath, "host", d.collector.Labels)
	d.log("info", "上传 Promtail 配置", "")
	if _, _, err := client.Execute(ctx, fmt.Sprintf("cat > /etc/promtail/promtail.yaml << 'EOF'\n%s\nEOF", conf)); err != nil {
		return fmt.Errorf("上传配置失败: %w", err)
	}

	// systemd 服务（生产级）
	service := `[Unit]
Description=Promtail Log Collector
Wants=network-online.target
After=network-online.target

[Service]
Type=simple
User=root
Group=root
ExecStart=/usr/local/bin/promtail -config.file=/etc/promtail/promtail.yaml -positions.enabled=true
ExecReload=/bin/kill -HUP $MAINPID
Restart=always
RestartSec=10
LimitNOFILE=65536
StandardOutput=append:/var/log/promtail.log
StandardError=append:/var/log/promtail.log

[Install]
WantedBy=multi-user.target
`
	d.log("info", "安装 systemd 服务", "")
	if _, _, err := client.Execute(ctx, fmt.Sprintf("cat > /etc/systemd/system/promtail.service << 'EOF'\n%s\nEOF", service)); err != nil {
		return fmt.Errorf("创建 systemd 服务失败: %w", err)
	}
	if _, _, err := client.Execute(ctx, "systemctl daemon-reload && systemctl enable promtail && systemctl restart promtail"); err != nil {
		return fmt.Errorf("启动 Promtail 失败: %w", err)
	}

	// 保存配置快照
	d.collector.Config = conf
	d.log("success", "Promtail 部署完成", "")
	return nil
}

func (d *CollectorDeployer) uninstallHost(ctx context.Context) error {
	host := d.collector.Host
	if host == nil {
		return nil
	}
	client, err := NewSSHClientWithAuth(HostSSHAuth(host))
	if err != nil {
		return err
	}
	defer client.Close()
	client.Execute(ctx, "systemctl stop promtail 2>/dev/null || true")
	client.Execute(ctx, "systemctl disable promtail 2>/dev/null || true")
	client.Execute(ctx, "rm -rf /etc/systemd/system/promtail.service /usr/local/bin/promtail /etc/promtail /opt/promtail /var/lib/promtail")
	client.Execute(ctx, "systemctl daemon-reload")
	return nil
}

// ===== k8s-daemonset：helm 安装 Promtail DaemonSet =====

func (d *CollectorDeployer) installDaemonset(ctx context.Context, endpoint string) error {
	cluster := d.collector.Cluster
	if cluster == nil {
		return fmt.Errorf("集群采集器缺少目标集群")
	}
	env, cleanup, err := kubeconfigEnv(cluster)
	if err != nil {
		return err
	}
	defer cleanup()

	// 默认部署到关联 Loki 的命名空间(统一 log 命名空间策略)
	ns := d.collector.Namespace
	if ns == "" && d.loki != nil {
		ns = d.loki.Namespace
	}
	if ns == "" {
		ns = "log"
	}

	clusterName := "unknown"
	if cluster.Name != "" {
		clusterName = cluster.Name
	}

	// 幂等:先清掉同名残留(如历史失败安装留下的无注解资源)
	del := exec.CommandContext(ctx, "kubectl", "delete",
		"daemonset/promtail", "configmap/promtail", "serviceaccount/promtail",
		"-n", ns, "--ignore-not-found=true", "--wait=false")
	del.Env = env
	del.CombinedOutput()

	// 纯 YAML 安装(SA/RBAC/ConfigMap/DaemonSet),不依赖后端安装 helm
	manifest := PromtailDaemonsetYAML(ns, endpoint, clusterName, d.collector.Labels)
	if err := d.applyYAML(ctx, env, manifest, "promtail"); err != nil {
		return err
	}

	d.log("info", fmt.Sprintf("等待 DaemonSet promtail 就绪(命名空间 %s)...", ns), "")
	waitCmd := exec.CommandContext(ctx, "kubectl", "rollout", "status", "daemonset/promtail",
		"-n", ns, "--timeout=5m")
	waitCmd.Env = env
	waitOut, _ := waitCmd.CombinedOutput()
	d.log("info", string(waitOut), "")

	// DNS 自愈:CoreDNS 异常的集群上服务名不可解析,回退 Loki ClusterIP 重建配置
	svcURL := endpoint
	if strings.Contains(endpoint, ".svc") {
		probe := exec.CommandContext(ctx, "kubectl", "exec", "-n", ns,
			"daemonset/promtail", "--", "wget", "-q", "-O", "/dev/null", "-T", "5", endpoint+"/ready")
		probe.Env = env
		if pout, perr := probe.CombinedOutput(); perr != nil {
			d.log("warn", fmt.Sprintf("promtail 无法解析 Loki 服务名(%s),回退 ClusterIP...", strings.TrimSpace(string(pout))), "")
			ip := d.lokiClusterIP(ctx, env, endpoint)
			if ip != "" {
				// 只替换 host 部分,保留 scheme/port/path: http://loki.ns.svc:3100/... → http://IP:3100/...
				afterScheme := strings.SplitN(endpoint, "//", 2)
				if len(afterScheme) == 2 {
					rest := afterScheme[1]
					host := rest
					if i := strings.IndexAny(rest, ":/"); i >= 0 {
						host = rest[:i]
					}
					fallback := afterScheme[0] + "//" + strings.Replace(rest, host, ip, 1)
					if err := d.applyYAML(ctx, env, PromtailDaemonsetYAML(ns, fallback, clusterName, d.collector.Labels), "promtail"); err == nil {
						rs := exec.CommandContext(ctx, "kubectl", "rollout", "restart", "daemonset/promtail", "-n", ns)
						rs.Env = env
						rs.CombinedOutput()
						d.log("info", fmt.Sprintf("promtail 推送地址已回退为 ClusterIP: %s", fallback), "")
						svcURL = fallback
					}
				}
			}
		}
	}

	d.collector.Config = svcURL
	d.log("success", fmt.Sprintf("Promtail DaemonSet 已部署到 %s(推送至 %s)", ns, svcURL), "")
	return nil
}

// applyYAML kubectl apply 一个 manifest(临时文件)
func (d *CollectorDeployer) applyYAML(ctx context.Context, env []string, manifest, label string) error {
	f, cleanup, err := writeTempFile("collector-*.yaml", manifest, 0600)
	if err != nil {
		return err
	}
	defer cleanup()
	cmd := exec.CommandContext(ctx, "kubectl", "apply", "-f", f)
	cmd.Env = env
	out, err := cmd.CombinedOutput()
	if err != nil {
		d.log("error", fmt.Sprintf("kubectl apply %s failed: %v", label, err), string(out))
		return fmt.Errorf("kubectl apply %s failed: %w\n%s", label, err, string(out))
	}
	return nil
}

// lokiClusterIP 从 endpoint 的命名空间取 loki Service 的 ClusterIP(不经 DNS)
func (d *CollectorDeployer) lokiClusterIP(ctx context.Context, env []string, endpoint string) string {
	ns := "log"
	if d.loki != nil && d.loki.Namespace != "" {
		ns = d.loki.Namespace
	}
	cmd := exec.CommandContext(ctx, "kubectl", "get", "svc", "loki", "-n", ns,
		"-o", "jsonpath={.spec.clusterIP}")
	cmd.Env = env
	out, _ := cmd.CombinedOutput()
	return strings.TrimSpace(string(out))
}

func (d *CollectorDeployer) uninstallDaemonset(ctx context.Context) error {
	cluster := d.collector.Cluster
	if cluster == nil {
		return nil
	}
	env, cleanup, err := kubeconfigEnv(cluster)
	if err != nil {
		return err
	}
	defer cleanup()
	ns := d.collector.Namespace
	if ns == "" && d.loki != nil {
		ns = d.loki.Namespace
	}
	if ns == "" {
		ns = "log"
	}
	cmd := exec.CommandContext(ctx, "kubectl", "delete",
		"daemonset/promtail", "configmap/promtail", "serviceaccount/promtail",
		"clusterrole/opsxloki-promtail", "clusterrolebinding/opsxloki-promtail",
		"-n", ns, "--ignore-not-found=true")
	cmd.Env = env
	cmd.CombinedOutput()
	return nil
}

// ===== k8s-fluentbit-sidecar：kubectl patch 注入 Fluent Bit sidecar =====

func (d *CollectorDeployer) installSidecar(ctx context.Context, endpoint string) error {
	cluster := d.collector.Cluster
	if cluster == nil {
		return fmt.Errorf("Sidecar 采集器缺少目标集群")
	}
	target := d.collector.TargetDeployment
	if target == "" {
		return fmt.Errorf("Sidecar 采集器缺少目标 Deployment")
	}
	env, cleanup, err := kubeconfigEnv(cluster)
	if err != nil {
		return err
	}
	defer cleanup()

	ns := d.collector.Namespace
	if ns == "" {
		ns = "default"
	}
	logPath := d.collector.LogPath
	if logPath == "" {
		logPath = "/var/log/app/*.log"
	}
	app := target

	// 1. 检查目标 deployment 是否存在
	d.log("info", fmt.Sprintf("检查目标 Deployment %s/%s", ns, target), "")
	check := exec.CommandContext(ctx, "kubectl", "get", "deployment", target, "-n", ns)
	check.Env = env
	if out, err := check.CombinedOutput(); err != nil {
		return fmt.Errorf("目标 Deployment 不存在: %s/%s\n%s", ns, target, string(out))
	}

	// 2. 幂等检查：是否已有 fluent-bit 容器
	getNames := exec.CommandContext(ctx, "kubectl", "get", "deployment", target, "-n", ns, "-o", "jsonpath={.spec.template.spec.containers[*].name}")
	getNames.Env = env
	namesOut, _ := getNames.CombinedOutput()
	if strings.Contains(string(namesOut), "fluent-bit") {
		d.log("warn", "目标 Deployment 已含 fluent-bit 容器，跳过注入", "")
		return nil
	}

	// 3. 部署 ConfigMap
	lokiHost, lokiPort := parseLokiURL(endpoint)
	conf := FluentbitConfig(lokiHost, lokiPort, logPath, app, ns)
	cm := FluentbitConfigMapYAML(conf, ns)
	cmFile, cmCleanup, err := writeTempFile("fluent-bit-cm-*.yaml", cm, 0600)
	if err != nil {
		return err
	}
	defer cmCleanup()

	d.log("info", "部署 Fluent Bit ConfigMap", "")
	applyCm := exec.CommandContext(ctx, "kubectl", "apply", "-f", cmFile)
	applyCm.Env = env
	if out, err := applyCm.CombinedOutput(); err != nil {
		return fmt.Errorf("ConfigMap 部署失败: %w\n%s", err, string(out))
	}

	// 4. patch 注入 sidecar
	d.log("info", fmt.Sprintf("为 %s 注入 Fluent Bit Sidecar", target), "")
	patchFile, patchCleanup, err := writeTempFile("sidecar-patch-*.yaml", SidecarPatchYAML, 0600)
	if err != nil {
		return err
	}
	defer patchCleanup()

	patch := exec.CommandContext(ctx, "kubectl", "patch", "deployment", target, "-n", ns, "--type=strategic", "--patch-file", patchFile)
	patch.Env = env
	if out, err := patch.CombinedOutput(); err != nil {
		return fmt.Errorf("Sidecar 注入失败: %w\n%s", err, string(out))
	}

	// 5. 等待 rollout
	d.log("info", "等待 Pod 重建", "")
	rollout := exec.CommandContext(ctx, "kubectl", "rollout", "status", "deployment/"+target, "-n", ns, "--timeout=5m")
	rollout.Env = env
	rollout.CombinedOutput()
	return nil
}

func (d *CollectorDeployer) uninstallSidecar(ctx context.Context) error {
	cluster := d.collector.Cluster
	if cluster == nil || d.collector.TargetDeployment == "" {
		return nil
	}
	env, cleanup, err := kubeconfigEnv(cluster)
	if err != nil {
		return err
	}
	defer cleanup()
	ns := d.collector.Namespace
	if ns == "" {
		ns = "default"
	}
	patchFile, patchCleanup, err := writeTempFile("sidecar-rm-*.yaml", SidecarRemovePatchYAML, 0600)
	if err != nil {
		return err
	}
	defer patchCleanup()

	patch := exec.CommandContext(ctx, "kubectl", "patch", "deployment", d.collector.TargetDeployment, "-n", ns, "--type=strategic", "--patch-file", patchFile)
	patch.Env = env
	patch.CombinedOutput()
	return nil
}