package main

import (
	"bufio"
	"fmt"
	"os"
	"path/filepath"
	"strconv"
	"strings"

	"github.com/bdw/ship/internal/ssh"
	"github.com/bdw/ship/internal/state"
	"github.com/bdw/ship/internal/templates"
	"github.com/spf13/cobra"
)

// DeployOptions contains all options for deploying or updating an app
type DeployOptions struct {
	Host     string
	Domain   string
	Name     string
	Binary   string
	Dir      string // for static sites
	Port     int
	Args     string
	Files    []string
	Memory   string
	CPU      string
	Env      map[string]string // merged env vars
	IsUpdate bool
}

func runDeploy(cmd *cobra.Command, args []string) error {
	flags := cmd.Flags()

	// Parse CLI flags
	binary, _ := flags.GetString("binary")
	static, _ := flags.GetBool("static")
	dir, _ := flags.GetString("dir")
	domain, _ := flags.GetString("domain")
	name, _ := flags.GetString("name")
	port, _ := flags.GetInt("port")
	envVars, _ := flags.GetStringArray("env")
	envFile, _ := flags.GetString("env-file")
	argsFlag, _ := flags.GetString("args")
	files, _ := flags.GetStringArray("file")
	memory, _ := flags.GetString("memory")
	cpu, _ := flags.GetString("cpu")

	// Get host from flag or state default
	host := hostFlag
	if host == "" {
		st, err := state.Load()
		if err != nil {
			return fmt.Errorf("error loading state: %w", err)
		}
		host = st.GetDefaultHost()
	}

	// If no flags provided, show help
	if domain == "" && binary == "" && !static && name == "" {
		return cmd.Help()
	}

	if host == "" {
		return fmt.Errorf("--host is required")
	}

	// Load state once - this will be used throughout
	st, err := state.Load()
	if err != nil {
		return fmt.Errorf("error loading state: %w", err)
	}
	hostState := st.GetHost(host)

	// Config update mode: --name provided without --binary or --static
	if name != "" && binary == "" && !static {
		existingApp, err := st.GetApp(host, name)
		if err != nil {
			return fmt.Errorf("app %s not found (use --binary to deploy a new app)", name)
		}

		// Build merged config starting from existing app
		opts := DeployOptions{
			Host:   host,
			Name:   name,
			Port:   existingApp.Port,
			Args:   existingApp.Args,
			Files:  existingApp.Files,
			Memory: existingApp.Memory,
			CPU:    existingApp.CPU,
			Env:    make(map[string]string),
		}
		for k, v := range existingApp.Env {
			opts.Env[k] = v
		}

		// Override with CLI flags if provided
		if argsFlag != "" {
			opts.Args = argsFlag
		}
		if len(files) > 0 {
			opts.Files = files
		}
		if memory != "" {
			opts.Memory = memory
		}
		if cpu != "" {
			opts.CPU = cpu
		}

		// Merge env vars (CLI overrides existing)
		for _, e := range envVars {
			parts := strings.SplitN(e, "=", 2)
			if len(parts) == 2 {
				opts.Env[parts[0]] = parts[1]
			}
		}
		if envFile != "" {
			fileEnv, err := parseEnvFile(envFile)
			if err != nil {
				return fmt.Errorf("error reading env file: %w", err)
			}
			for k, v := range fileEnv {
				opts.Env[k] = v
			}
		}

		return updateAppConfig(st, opts)
	}

	// Infer name early so we can use it for subdomain generation and existing app lookup
	if name == "" {
		if static {
			name = domain
			if name == "" && hostState.BaseDomain != "" {
				name = filepath.Base(dir)
			}
		} else {
			name = filepath.Base(binary)
		}
	}

	// Check if this is an update to an existing app/site
	existingApp, _ := st.GetApp(host, name)
	isUpdate := existingApp != nil

	// For new deployments, require domain or base domain
	if !isUpdate && domain == "" && hostState.BaseDomain == "" {
		return fmt.Errorf("--domain required (or configure base domain with 'ship host init --base-domain')")
	}

	// Build merged config, starting from existing app if updating
	opts := DeployOptions{
		Host:     host,
		Name:     name,
		Binary:   binary,
		Dir:      dir,
		IsUpdate: isUpdate,
	}

	// Merge domain: auto-subdomain + (user-provided or existing custom domain)
	var domains []string
	if hostState.BaseDomain != "" {
		domains = append(domains, name+"."+hostState.BaseDomain)
	}
	if domain != "" {
		domains = append(domains, domain)
	} else if isUpdate && existingApp.Domain != "" {
		for _, d := range strings.Split(existingApp.Domain, ",") {
			d = strings.TrimSpace(d)
			if d != "" && (hostState.BaseDomain == "" || !strings.HasSuffix(d, "."+hostState.BaseDomain)) {
				domains = append(domains, d)
			}
		}
	}
	opts.Domain = strings.Join(domains, ", ")

	// For apps, merge all config fields
	if !static {
		// Start with existing values if updating
		if isUpdate {
			opts.Port = existingApp.Port
			opts.Args = existingApp.Args
			opts.Files = existingApp.Files
			opts.Memory = existingApp.Memory
			opts.CPU = existingApp.CPU
			opts.Env = make(map[string]string)
			for k, v := range existingApp.Env {
				opts.Env[k] = v
			}
		} else {
			opts.Port = port
			opts.Env = make(map[string]string)
		}

		// Override with CLI flags if provided
		if argsFlag != "" {
			opts.Args = argsFlag
		}
		if len(files) > 0 {
			opts.Files = files
		}
		if memory != "" {
			opts.Memory = memory
		}
		if cpu != "" {
			opts.CPU = cpu
		}

		// Merge env vars (CLI overrides existing)
		for _, e := range envVars {
			parts := strings.SplitN(e, "=", 2)
			if len(parts) == 2 {
				opts.Env[parts[0]] = parts[1]
			}
		}
		if envFile != "" {
			fileEnv, err := parseEnvFile(envFile)
			if err != nil {
				return fmt.Errorf("error reading env file: %w", err)
			}
			for k, v := range fileEnv {
				opts.Env[k] = v
			}
		}
	}

	if static {
		return deployStatic(st, opts)
	}
	return deployApp(st, opts)
}

func deployApp(st *state.State, opts DeployOptions) error {
	if opts.Binary == "" {
		return fmt.Errorf("--binary is required")
	}

	if _, err := os.Stat(opts.Binary); err != nil {
		return fmt.Errorf("binary not found: %s", opts.Binary)
	}

	fmt.Printf("Deploying app: %s\n", opts.Name)
	fmt.Printf("  Domain(s): %s\n", opts.Domain)
	fmt.Printf("  Binary: %s\n", opts.Binary)

	// Allocate port for new apps
	port := opts.Port
	if opts.IsUpdate {
		fmt.Printf("  Updating existing deployment (port %d)\n", port)
	} else {
		if port == 0 {
			port = st.AllocatePort(opts.Host)
		}
		fmt.Printf("  Allocated port: %d\n", port)
	}

	// Add PORT to env
	opts.Env["PORT"] = strconv.Itoa(port)

	client, err := ssh.Connect(opts.Host)
	if err != nil {
		return fmt.Errorf("error connecting to VPS: %w", err)
	}
	defer client.Close()

	fmt.Println("-> Uploading binary...")
	remoteTmpPath := fmt.Sprintf("/tmp/%s", opts.Name)
	if err := client.Upload(opts.Binary, remoteTmpPath); err != nil {
		return fmt.Errorf("error uploading binary: %w", err)
	}

	fmt.Println("-> Creating system user...")
	client.RunSudo(fmt.Sprintf("useradd -r -s /bin/false %s", opts.Name))

	fmt.Println("-> Setting up directories...")
	workDir := fmt.Sprintf("/var/lib/%s", opts.Name)
	if _, err := client.RunSudo(fmt.Sprintf("mkdir -p %s", workDir)); err != nil {
		return fmt.Errorf("error creating work directory: %w", err)
	}
	if _, err := client.RunSudo(fmt.Sprintf("chown %s:%s %s", opts.Name, opts.Name, workDir)); err != nil {
		return fmt.Errorf("error setting work directory ownership: %w", err)
	}

	fmt.Println("-> Installing binary...")
	binaryDest := fmt.Sprintf("/usr/local/bin/%s", opts.Name)
	if _, err := client.RunSudo(fmt.Sprintf("mv %s %s", remoteTmpPath, binaryDest)); err != nil {
		return fmt.Errorf("error moving binary: %w", err)
	}
	if _, err := client.RunSudo(fmt.Sprintf("chmod +x %s", binaryDest)); err != nil {
		return fmt.Errorf("error making binary executable: %w", err)
	}

	if len(opts.Files) > 0 {
		fmt.Println("-> Uploading config files...")
		for _, file := range opts.Files {
			if _, err := os.Stat(file); err != nil {
				return fmt.Errorf("config file not found: %s", file)
			}

			remotePath := fmt.Sprintf("%s/%s", workDir, filepath.Base(file))
			fileTmpPath := fmt.Sprintf("/tmp/%s_%s", opts.Name, filepath.Base(file))

			if err := client.Upload(file, fileTmpPath); err != nil {
				return fmt.Errorf("error uploading config file %s: %w", file, err)
			}

			if _, err := client.RunSudo(fmt.Sprintf("mv %s %s", fileTmpPath, remotePath)); err != nil {
				return fmt.Errorf("error moving config file %s: %w", file, err)
			}

			if _, err := client.RunSudo(fmt.Sprintf("chown %s:%s %s", opts.Name, opts.Name, remotePath)); err != nil {
				return fmt.Errorf("error setting config file ownership %s: %w", file, err)
			}

			fmt.Printf("  Uploaded: %s\n", file)
		}
	}

	fmt.Println("-> Creating environment file...")
	envFilePath := fmt.Sprintf("/etc/ship/env/%s.env", opts.Name)
	envContent := ""
	for k, v := range opts.Env {
		envContent += fmt.Sprintf("%s=%s\n", k, v)
	}
	if err := client.WriteSudoFile(envFilePath, envContent); err != nil {
		return fmt.Errorf("error creating env file: %w", err)
	}
	if _, err := client.RunSudo(fmt.Sprintf("chmod 600 %s", envFilePath)); err != nil {
		return fmt.Errorf("error setting env file permissions: %w", err)
	}
	if _, err := client.RunSudo(fmt.Sprintf("chown %s:%s %s", opts.Name, opts.Name, envFilePath)); err != nil {
		return fmt.Errorf("error setting env file ownership: %w", err)
	}

	fmt.Println("-> Creating systemd service...")
	serviceContent, err := templates.SystemdService(map[string]string{
		"Name":       opts.Name,
		"User":       opts.Name,
		"WorkDir":    workDir,
		"BinaryPath": binaryDest,
		"Port":       strconv.Itoa(port),
		"EnvFile":    envFilePath,
		"Args":       opts.Args,
		"Memory":     opts.Memory,
		"CPU":        opts.CPU,
	})
	if err != nil {
		return fmt.Errorf("error generating systemd unit: %w", err)
	}

	servicePath := fmt.Sprintf("/etc/systemd/system/%s.service", opts.Name)
	if err := client.WriteSudoFile(servicePath, serviceContent); err != nil {
		return fmt.Errorf("error creating systemd unit: %w", err)
	}

	fmt.Println("-> Configuring Caddy...")
	caddyContent, err := templates.AppCaddy(map[string]string{
		"Domain": opts.Domain,
		"Port":   strconv.Itoa(port),
	})
	if err != nil {
		return fmt.Errorf("error generating Caddy config: %w", err)
	}

	caddyPath := fmt.Sprintf("/etc/caddy/sites-enabled/%s.caddy", opts.Name)
	if err := client.WriteSudoFile(caddyPath, caddyContent); err != nil {
		return fmt.Errorf("error creating Caddy config: %w", err)
	}

	fmt.Println("-> Reloading systemd...")
	if _, err := client.RunSudo("systemctl daemon-reload"); err != nil {
		return fmt.Errorf("error reloading systemd: %w", err)
	}

	fmt.Println("-> Starting service...")
	if _, err := client.RunSudo(fmt.Sprintf("systemctl enable %s", opts.Name)); err != nil {
		return fmt.Errorf("error enabling service: %w", err)
	}
	if _, err := client.RunSudo(fmt.Sprintf("systemctl restart %s", opts.Name)); err != nil {
		return fmt.Errorf("error starting service: %w", err)
	}

	fmt.Println("-> Reloading Caddy...")
	if _, err := client.RunSudo("systemctl reload caddy"); err != nil {
		return fmt.Errorf("error reloading Caddy: %w", err)
	}

	st.AddApp(opts.Host, opts.Name, &state.App{
		Type:   "app",
		Domain: opts.Domain,
		Port:   port,
		Env:    opts.Env,
		Args:   opts.Args,
		Files:  opts.Files,
		Memory: opts.Memory,
		CPU:    opts.CPU,
	})
	if err := st.Save(); err != nil {
		return fmt.Errorf("error saving state: %w", err)
	}

	fmt.Printf("\n App deployed successfully!\n")
	// Show first domain in the URL message
	primaryDomain := strings.Split(opts.Domain, ",")[0]
	primaryDomain = strings.TrimSpace(primaryDomain)
	fmt.Printf("  https://%s (may take a minute for HTTPS cert)\n", primaryDomain)
	return nil
}

func updateAppConfig(st *state.State, opts DeployOptions) error {
	existingApp, err := st.GetApp(opts.Host, opts.Name)
	if err != nil {
		return fmt.Errorf("app %s not found (use --binary to deploy a new app)", opts.Name)
	}

	if existingApp.Type != "app" && existingApp.Type != "git-app" {
		return fmt.Errorf("%s is a static site, not an app", opts.Name)
	}

	fmt.Printf("Updating config: %s\n", opts.Name)

	// Add PORT to env
	opts.Env["PORT"] = strconv.Itoa(existingApp.Port)

	client, err := ssh.Connect(opts.Host)
	if err != nil {
		return fmt.Errorf("error connecting to VPS: %w", err)
	}
	defer client.Close()

	// Update env file
	fmt.Println("-> Updating environment file...")
	envFilePath := fmt.Sprintf("/etc/ship/env/%s.env", opts.Name)
	envContent := ""
	for k, v := range opts.Env {
		envContent += fmt.Sprintf("%s=%s\n", k, v)
	}
	if err := client.WriteSudoFile(envFilePath, envContent); err != nil {
		return fmt.Errorf("error creating env file: %w", err)
	}

	// For git-app, the systemd unit comes from .ship/service in the repo,
	// so we only update the env file and restart.
	if existingApp.Type != "git-app" {
		// Regenerate systemd unit
		fmt.Println("-> Updating systemd service...")
		workDir := fmt.Sprintf("/var/lib/%s", opts.Name)
		binaryDest := fmt.Sprintf("/usr/local/bin/%s", opts.Name)
		serviceContent, err := templates.SystemdService(map[string]string{
			"Name":       opts.Name,
			"User":       opts.Name,
			"WorkDir":    workDir,
			"BinaryPath": binaryDest,
			"Port":       strconv.Itoa(existingApp.Port),
			"EnvFile":    envFilePath,
			"Args":       opts.Args,
			"Memory":     opts.Memory,
			"CPU":        opts.CPU,
		})
		if err != nil {
			return fmt.Errorf("error generating systemd unit: %w", err)
		}

		servicePath := fmt.Sprintf("/etc/systemd/system/%s.service", opts.Name)
		if err := client.WriteSudoFile(servicePath, serviceContent); err != nil {
			return fmt.Errorf("error creating systemd unit: %w", err)
		}

		fmt.Println("-> Reloading systemd...")
		if _, err := client.RunSudo("systemctl daemon-reload"); err != nil {
			return fmt.Errorf("error reloading systemd: %w", err)
		}
	}

	fmt.Println("-> Restarting service...")
	if _, err := client.RunSudo(fmt.Sprintf("systemctl restart %s", opts.Name)); err != nil {
		return fmt.Errorf("error restarting service: %w", err)
	}

	// Update state
	existingApp.Args = opts.Args
	existingApp.Memory = opts.Memory
	existingApp.CPU = opts.CPU
	existingApp.Env = opts.Env
	if err := st.Save(); err != nil {
		return fmt.Errorf("error saving state: %w", err)
	}

	fmt.Printf("\n Config updated successfully!\n")
	return nil
}

func deployStatic(st *state.State, opts DeployOptions) error {
	if _, err := os.Stat(opts.Dir); err != nil {
		return fmt.Errorf("directory not found: %s", opts.Dir)
	}

	fmt.Printf("Deploying static site: %s\n", opts.Name)
	fmt.Printf("  Domain(s): %s\n", opts.Domain)
	fmt.Printf("  Directory: %s\n", opts.Dir)

	if opts.IsUpdate {
		fmt.Println("  Updating existing deployment")
	}

	client, err := ssh.Connect(opts.Host)
	if err != nil {
		return fmt.Errorf("error connecting to VPS: %w", err)
	}
	defer client.Close()

	remoteDir := fmt.Sprintf("/var/www/%s", opts.Name)
	fmt.Println("-> Creating remote directory...")
	if _, err := client.RunSudo(fmt.Sprintf("mkdir -p %s", remoteDir)); err != nil {
		return fmt.Errorf("error creating remote directory: %w", err)
	}

	currentUser, err := client.Run("whoami")
	if err != nil {
		return fmt.Errorf("error getting current user: %w", err)
	}
	currentUser = strings.TrimSpace(currentUser)

	if _, err := client.RunSudo(fmt.Sprintf("chown -R %s:%s %s", currentUser, currentUser, remoteDir)); err != nil {
		return fmt.Errorf("error setting temporary ownership: %w", err)
	}

	fmt.Println("-> Uploading files...")
	if err := client.UploadDir(opts.Dir, remoteDir); err != nil {
		return fmt.Errorf("error uploading files: %w", err)
	}

	fmt.Println("-> Setting permissions...")
	if _, err := client.RunSudo(fmt.Sprintf("chown -R www-data:www-data %s", remoteDir)); err != nil {
		return fmt.Errorf("error setting ownership: %w", err)
	}
	if _, err := client.RunSudo(fmt.Sprintf("chmod -R 755 %s", remoteDir)); err != nil {
		return fmt.Errorf("error setting directory permissions: %w", err)
	}
	if _, err := client.RunSudo(fmt.Sprintf("find %s -type f -exec chmod 644 {} \\;", remoteDir)); err != nil {
		return fmt.Errorf("error setting file permissions: %w", err)
	}

	fmt.Println("-> Configuring Caddy...")
	caddyContent, err := templates.StaticCaddy(map[string]string{
		"Domain":  opts.Domain,
		"RootDir": remoteDir,
	})
	if err != nil {
		return fmt.Errorf("error generating Caddy config: %w", err)
	}

	caddyPath := fmt.Sprintf("/etc/caddy/sites-enabled/%s.caddy", opts.Name)
	if err := client.WriteSudoFile(caddyPath, caddyContent); err != nil {
		return fmt.Errorf("error creating Caddy config: %w", err)
	}

	fmt.Println("-> Reloading Caddy...")
	if _, err := client.RunSudo("systemctl reload caddy"); err != nil {
		return fmt.Errorf("error reloading Caddy: %w", err)
	}

	st.AddApp(opts.Host, opts.Name, &state.App{
		Type:   "static",
		Domain: opts.Domain,
	})
	if err := st.Save(); err != nil {
		return fmt.Errorf("error saving state: %w", err)
	}

	fmt.Printf("\n Static site deployed successfully!\n")
	primaryDomain := strings.Split(opts.Domain, ",")[0]
	primaryDomain = strings.TrimSpace(primaryDomain)
	fmt.Printf("  https://%s (may take a minute for HTTPS cert)\n", primaryDomain)
	return nil
}

func parseEnvFile(path string) (map[string]string, error) {
	file, err := os.Open(path)
	if err != nil {
		return nil, err
	}
	defer file.Close()

	env := make(map[string]string)
	scanner := bufio.NewScanner(file)
	for scanner.Scan() {
		line := strings.TrimSpace(scanner.Text())
		if line == "" || strings.HasPrefix(line, "#") {
			continue
		}

		parts := strings.SplitN(line, "=", 2)
		if len(parts) == 2 {
			env[parts[0]] = parts[1]
		}
	}

	return env, scanner.Err()
}