package modules

import (
	"fmt"
	"os"
	"path/filepath"
	"strings"
	"sync"
	"time"

	"github.com/sirupsen/logrus"
)

// DebianModulesManager handles Debian-adapted blue-build modules
type DebianModulesManager struct {
	logger       *logrus.Logger
	config       *ModulesConfig
	modules      map[string]DebianModule
	adaptations  map[string]ModuleAdaptation
	mu           sync.RWMutex
}

// ModulesConfig holds modules configuration
type ModulesConfig struct {
	Enabled       bool              `json:"enabled"`
	ModulesPath   string            `json:"modules_path"`
	Adaptations   bool              `json:"adaptations"`
	Validation    bool              `json:"validation"`
	Metadata      map[string]string `json:"metadata"`
}

// DebianModule represents a Debian-adapted module
type DebianModule struct {
	ID          string                 `json:"id"`
	Name        string                 `json:"name"`
	Description string                 `json:"description"`
	Type        string                 `json:"type"`
	Source      string                 `json:"source"`
	Adapted     bool                   `json:"adapted"`
	Enabled     bool                   `json:"enabled"`
	Metadata    map[string]interface{} `json:"metadata"`
}

// ModuleAdaptation represents module adaptation from blue-build
type ModuleAdaptation struct {
	ID          string                 `json:"id"`
	OriginalID  string                 `json:"original_id"`
	Name        string                 `json:"name"`
	Description string                 `json:"description"`
	Type        string                 `json:"type"`
	Changes     []string               `json:"changes"`
	Status      string                 `json:"status"`
	Enabled     bool                   `json:"enabled"`
	Metadata    map[string]interface{} `json:"metadata"`
}

// NewDebianModulesManager creates a new Debian modules manager
func NewDebianModulesManager(config *ModulesConfig, logger *logrus.Logger) *DebianModulesManager {
	manager := &DebianModulesManager{
		logger:      logger,
		config:      config,
		modules:     make(map[string]DebianModule),
		adaptations: make(map[string]ModuleAdaptation),
	}
	
	// Initialize Debian modules
	manager.initializeDebianModules()
	manager.initializeModuleAdaptations()
	
	return manager
}

// initializeDebianModules initializes Debian-specific modules
func (dmm *DebianModulesManager) initializeDebianModules() {
	// APT package management module (Debian equivalent of dnf)
	dmm.modules["apt"] = DebianModule{
		ID:          "apt",
		Name:        "APT Package Management",
		Description: "Debian package and repository management using apt",
		Type:        "apt",
		Source:      "debian-native",
		Adapted:     false,
		Enabled:     true,
		Metadata: map[string]interface{}{
			"package_manager": "apt",
			"repository_type": "deb",
		},
	}
	
	// dpkg module (Debian equivalent of rpm-ostree)
	dmm.modules["dpkg"] = DebianModule{
		ID:          "dpkg",
		Name:        "DPKG Package Management",
		Description: "Debian package management using dpkg",
		Type:        "dpkg",
		Source:      "debian-native",
		Adapted:     false,
		Enabled:     true,
		Metadata: map[string]interface{}{
			"package_manager": "dpkg",
			"package_format":  "deb",
		},
	}
	
	// Debian-specific modules
	dmm.modules["debian-release"] = DebianModule{
		ID:          "debian-release",
		Name:        "Debian Release Management",
		Description: "Manage Debian release information and configuration",
		Type:        "debian-release",
		Source:      "debian-native",
		Adapted:     false,
		Enabled:     true,
		Metadata: map[string]interface{}{
			"release_type": "debian",
			"config_path":  "/etc/debian_version",
		},
	}
	
	// Debian kernel modules
	dmm.modules["debian-kernel"] = DebianModule{
		ID:          "debian-kernel",
		Name:        "Debian Kernel Management",
		Description: "Manage Debian kernel configurations and modules",
		Type:        "debian-kernel",
		Source:      "debian-native",
		Adapted:     false,
		Enabled:     true,
		Metadata: map[string]interface{}{
			"kernel_type": "debian",
			"module_path": "/lib/modules",
		},
	}
	
	// Debian initramfs
	dmm.modules["debian-initramfs"] = DebianModule{
		ID:          "debian-initramfs",
		Name:        "Debian Initramfs",
		Description: "Manage Debian initramfs configuration",
		Type:        "debian-initramfs",
		Source:      "debian-native",
		Adapted:     false,
		Enabled:     true,
		Metadata: map[string]interface{}{
			"initramfs_type": "debian",
			"config_path":    "/etc/initramfs-tools",
		},
	}
}

// initializeModuleAdaptations initializes adaptations from blue-build modules
func (dmm *DebianModulesManager) initializeModuleAdaptations() {
	// DNF to APT adaptation
	dmm.adaptations["dnf-to-apt"] = ModuleAdaptation{
		ID:          "dnf-to-apt",
		OriginalID:  "dnf",
		Name:        "DNF to APT Adaptation",
		Description: "Adapt DNF module functionality for Debian APT",
		Type:        "adaptation",
		Changes: []string{
			"Replace dnf with apt",
			"Replace RPM repositories with DEB repositories",
			"Adapt package installation syntax",
			"Replace COPR with Debian backports",
		},
		Status:   "completed",
		Enabled:  true,
		Metadata: map[string]interface{}{
			"original_module": "dnf",
			"target_module":   "apt",
			"compatibility":   "high",
		},
	}
	
	// RPM-OSTree to DPKG adaptation
	dmm.adaptations["rpm-ostree-to-dpkg"] = ModuleAdaptation{
		ID:          "rpm-ostree-to-dpkg",
		OriginalID:  "rpm-ostree",
		Name:        "RPM-OSTree to DPKG Adaptation",
		Description: "Adapt RPM-OSTree module functionality for Debian DPKG",
		Type:        "adaptation",
		Changes: []string{
			"Replace rpm-ostree with dpkg",
			"Replace RPM packages with DEB packages",
			"Adapt repository management",
			"Replace COPR with Debian backports",
		},
		Status:   "completed",
		Enabled:  true,
		Metadata: map[string]interface{}{
			"original_module": "rpm-ostree",
			"target_module":   "dpkg",
			"compatibility":   "high",
		},
	}
	
	// OS Release adaptation
	dmm.adaptations["os-release-to-debian"] = ModuleAdaptation{
		ID:          "os-release-to-debian",
		OriginalID:  "os-release",
		Name:        "OS Release to Debian Adaptation",
		Description: "Adapt OS release module for Debian",
		Type:        "adaptation",
		Changes: []string{
			"Replace Fedora-specific paths with Debian paths",
			"Adapt release file format",
			"Update version detection logic",
		},
		Status:   "completed",
		Enabled:  true,
		Metadata: map[string]interface{}{
			"original_module": "os-release",
			"target_module":   "debian-release",
			"compatibility":   "high",
		},
	}
	
	// SystemD adaptation (mostly compatible)
	dmm.adaptations["systemd-debian"] = ModuleAdaptation{
		ID:          "systemd-debian",
		OriginalID:  "systemd",
		Name:        "SystemD Debian Adaptation",
		Description: "Adapt SystemD module for Debian",
		Type:        "adaptation",
		Changes: []string{
			"Verify Debian systemd compatibility",
			"Adapt unit file paths if needed",
			"Ensure Debian-specific configurations",
		},
		Status:   "completed",
		Enabled:  true,
		Metadata: map[string]interface{}{
			"original_module": "systemd",
			"target_module":   "systemd",
			"compatibility":   "high",
		},
	}
}

// GetModule returns a module by ID
func (dmm *DebianModulesManager) GetModule(moduleID string) (*DebianModule, error) {
	dmm.mu.RLock()
	defer dmm.mu.RUnlock()
	
	module, exists := dmm.modules[moduleID]
	if !exists {
		return nil, fmt.Errorf("module not found: %s", moduleID)
	}
	
	return &module, nil
}

// GetAdaptation returns an adaptation by ID
func (dmm *DebianModulesManager) GetAdaptation(adaptationID string) (*ModuleAdaptation, error) {
	dmm.mu.RLock()
	defer dmm.mu.RUnlock()
	
	adaptation, exists := dmm.adaptations[adaptationID]
	if !exists {
		return nil, fmt.Errorf("adaptation not found: %s", adaptationID)
	}
	
	return &adaptation, nil
}

// ListModules returns all available modules
func (dmm *DebianModulesManager) ListModules() []DebianModule {
	dmm.mu.RLock()
	defer dmm.mu.RUnlock()
	
	modules := make([]DebianModule, 0, len(dmm.modules))
	for _, module := range dmm.modules {
		if module.Enabled {
			modules = append(modules, module)
		}
	}
	
	return modules
}

// ListAdaptations returns all available adaptations
func (dmm *DebianModulesManager) ListAdaptations() []ModuleAdaptation {
	dmm.mu.RLock()
	defer dmm.mu.RUnlock()
	
	adaptations := make([]ModuleAdaptation, 0, len(dmm.adaptations))
	for _, adaptation := range dmm.adaptations {
		if adaptation.Enabled {
			adaptations = append(adaptations, adaptation)
		}
	}
	
	return adaptations
}

// ValidateModule validates a module configuration
func (dmm *DebianModulesManager) ValidateModule(moduleID string, config map[string]interface{}) error {
	module, err := dmm.GetModule(moduleID)
	if err != nil {
		return err
	}
	
	// Module-specific validation
	switch module.Type {
	case "apt":
		return dmm.validateAPTModule(config)
	case "dpkg":
		return dmm.validateDPKGModule(config)
	case "debian-release":
		return dmm.validateDebianReleaseModule(config)
	case "debian-kernel":
		return dmm.validateDebianKernelModule(config)
	case "debian-initramfs":
		return dmm.validateDebianInitramfsModule(config)
	default:
		return fmt.Errorf("unknown module type: %s", module.Type)
	}
}

// validateAPTModule validates APT module configuration
func (dmm *DebianModulesManager) validateAPTModule(config map[string]interface{}) error {
	// Validate required fields
	if _, ok := config["repos"]; !ok {
		return fmt.Errorf("APT module requires 'repos' configuration")
	}
	
	if _, ok := config["install"]; !ok {
		return fmt.Errorf("APT module requires 'install' configuration")
	}
	
	return nil
}

// validateDPKGModule validates DPKG module configuration
func (dmm *DebianModulesManager) validateDPKGModule(config map[string]interface{}) error {
	// Validate required fields
	if _, ok := config["packages"]; !ok {
		return fmt.Errorf("DPKG module requires 'packages' configuration")
	}
	
	return nil
}

// validateDebianReleaseModule validates Debian release module configuration
func (dmm *DebianModulesManager) validateDebianReleaseModule(config map[string]interface{}) error {
	// Validate required fields
	if _, ok := config["release"]; !ok {
		return fmt.Errorf("Debian release module requires 'release' configuration")
	}
	
	return nil
}

// validateDebianKernelModule validates Debian kernel module configuration
func (dmm *DebianModulesManager) validateDebianKernelModule(config map[string]interface{}) error {
	// Validate required fields
	if _, ok := config["kernel"]; !ok {
		return fmt.Errorf("Debian kernel module requires 'kernel' configuration")
	}
	
	return nil
}

// validateDebianInitramfsModule validates Debian initramfs module configuration
func (dmm *DebianModulesManager) validateDebianInitramfsModule(config map[string]interface{}) error {
	// Validate required fields
	if _, ok := config["initramfs"]; !ok {
		return fmt.Errorf("Debian initramfs module requires 'initramfs' configuration")
	}
	
	return nil
}

// CreateModuleTemplate creates a template for a module
func (dmm *DebianModulesManager) CreateModuleTemplate(moduleID string) (map[string]interface{}, error) {
	module, err := dmm.GetModule(moduleID)
	if err != nil {
		return nil, err
	}
	
	// Create module-specific templates
	switch module.Type {
	case "apt":
		return dmm.createAPTTemplate()
	case "dpkg":
		return dmm.createDPKGTemplate()
	case "debian-release":
		return dmm.createDebianReleaseTemplate()
	case "debian-kernel":
		return dmm.createDebianKernelTemplate()
	case "debian-initramfs":
		return dmm.createDebianInitramfsTemplate()
	default:
		return nil, fmt.Errorf("unknown module type: %s", module.Type)
	}
}

// createAPTTemplate creates an APT module template
func (dmm *DebianModulesManager) createAPTTemplate() map[string]interface{} {
	return map[string]interface{}{
		"type": "apt",
		"repos": map[string]interface{}{
			"cleanup": true,
			"files": []string{
				"https://example.com/debian-repo.list",
			},
			"keys": []string{
				"https://example.com/debian-repo.gpg",
			},
		},
		"install": map[string]interface{}{
			"packages": []string{
				"package1",
				"package2",
			},
		},
		"remove": map[string]interface{}{
			"packages": []string{
				"unwanted-package",
			},
		},
	}
}

// createDPKGTemplate creates a DPKG module template
func (dmm *DebianModulesManager) createDPKGTemplate() map[string]interface{} {
	return map[string]interface{}{
		"type": "dpkg",
		"packages": []string{
			"https://example.com/package.deb",
			"local-package.deb",
		},
		"remove": []string{
			"unwanted-package",
		},
	}
}

// createDebianReleaseTemplate creates a Debian release module template
func (dmm *DebianModulesManager) createDebianReleaseTemplate() map[string]interface{} {
	return map[string]interface{}{
		"type": "debian-release",
		"release": "bookworm",
		"codename": "Debian Bookworm",
		"version": "12",
	}
}

// createDebianKernelTemplate creates a Debian kernel module template
func (dmm *DebianModulesManager) createDebianKernelTemplate() map[string]interface{} {
	return map[string]interface{}{
		"type": "debian-kernel",
		"kernel": "linux-image-amd64",
		"modules": []string{
			"overlay",
			"bridge",
		},
		"parameters": map[string]string{
			"console": "ttyS0",
			"root": "/dev/sda1",
		},
	}
}

// createDebianInitramfsTemplate creates a Debian initramfs module template
func (dmm *DebianModulesManager) createDebianInitramfsTemplate() map[string]interface{} {
	return map[string]interface{}{
		"type": "debian-initramfs",
		"initramfs": "initramfs-tools",
		"config": map[string]interface{}{
			"modules": []string{
				"overlay",
				"bridge",
			},
			"hooks": []string{
				"resume",
				"rootfs",
			},
		},
	}
}