package converter

import (
	"encoding/json"
	"fmt"
	"os"
	"sort"

	"github.com/nvm/kportal/internal/config"
	"gopkg.in/yaml.v3"
)

// KFTrayConfig represents a single port-forward entry from kftray JSON format
type KFTrayConfig struct {
	Service      string `json:"service"`
	Namespace    string `json:"namespace"`
	LocalPort    int    `json:"local_port"`
	RemotePort   int    `json:"remote_port"`
	Context      string `json:"context"`
	WorkloadType string `json:"workload_type"`
	Protocol     string `json:"protocol"`
	Alias        string `json:"alias"`
}

// ConvertKFTrayToKPortal converts kftray JSON configuration to kportal YAML format
func ConvertKFTrayToKPortal(inputFile, outputFile string) error {
	// Read kftray JSON config
	// #nosec G304 -- inputFile is from command line argument for explicit conversion
	data, err := os.ReadFile(inputFile)
	if err != nil {
		return fmt.Errorf("failed to read input file: %w", err)
	}

	var kftrayConfigs []KFTrayConfig
	if err := json.Unmarshal(data, &kftrayConfigs); err != nil {
		return fmt.Errorf("failed to parse JSON: %w", err)
	}

	// Convert to kportal format
	kportalConfig := convertToKPortal(kftrayConfigs)

	// Write kportal YAML config
	yamlData, err := yaml.Marshal(kportalConfig)
	if err != nil {
		return fmt.Errorf("failed to generate YAML: %w", err)
	}

	// Add header comment
	header := "# kportal configuration converted from kftray format\n# Generated by kportal --convert\n\n"
	yamlData = append([]byte(header), yamlData...)

	if err := os.WriteFile(outputFile, yamlData, 0600); err != nil {
		return fmt.Errorf("failed to write output file: %w", err)
	}

	return nil
}

// GetConversionSummary returns statistics about the kftray configuration
func GetConversionSummary(inputFile string) (map[string]map[string]int, int, error) {
	// #nosec G304 -- inputFile is from command line argument for explicit conversion
	data, err := os.ReadFile(inputFile)
	if err != nil {
		return nil, 0, fmt.Errorf("failed to read input file: %w", err)
	}

	var kftrayConfigs []KFTrayConfig
	if err := json.Unmarshal(data, &kftrayConfigs); err != nil {
		return nil, 0, fmt.Errorf("failed to parse JSON: %w", err)
	}

	contextMap := make(map[string]map[string]int)
	for _, cfg := range kftrayConfigs {
		if _, ok := contextMap[cfg.Context]; !ok {
			contextMap[cfg.Context] = make(map[string]int)
		}
		contextMap[cfg.Context][cfg.Namespace]++
	}

	return contextMap, len(kftrayConfigs), nil
}

func convertToKPortal(kftrayConfigs []KFTrayConfig) config.Config {
	// Group by context and namespace
	contextMap := make(map[string]map[string][]forwardEntry)

	for _, cfg := range kftrayConfigs {
		// Initialize context if not exists
		if _, ok := contextMap[cfg.Context]; !ok {
			contextMap[cfg.Context] = make(map[string][]forwardEntry)
		}

		// Build resource string based on workload type
		resource := fmt.Sprintf("%s/%s", cfg.WorkloadType, cfg.Service)

		// Create forward entry
		forward := forwardEntry{
			Resource:  resource,
			Protocol:  cfg.Protocol,
			Port:      cfg.RemotePort,
			LocalPort: cfg.LocalPort,
			Alias:     cfg.Alias,
		}

		// Add to namespace
		contextMap[cfg.Context][cfg.Namespace] = append(
			contextMap[cfg.Context][cfg.Namespace],
			forward,
		)
	}

	// Convert map to structured config
	var contexts []contextEntry

	// Sort contexts for consistent output
	contextNames := make([]string, 0, len(contextMap))
	for name := range contextMap {
		contextNames = append(contextNames, name)
	}
	sort.Strings(contextNames)

	for _, contextName := range contextNames {
		namespaceMap := contextMap[contextName]

		// Sort namespaces
		namespaceNames := make([]string, 0, len(namespaceMap))
		for name := range namespaceMap {
			namespaceNames = append(namespaceNames, name)
		}
		sort.Strings(namespaceNames)

		var namespaces []namespaceEntry
		for _, namespaceName := range namespaceNames {
			forwards := namespaceMap[namespaceName]

			// Sort forwards by local port for consistent output
			sort.Slice(forwards, func(i, j int) bool {
				return forwards[i].LocalPort < forwards[j].LocalPort
			})

			namespaces = append(namespaces, namespaceEntry{
				Name:     namespaceName,
				Forwards: forwards,
			})
		}

		contexts = append(contexts, contextEntry{
			Name:       contextName,
			Namespaces: namespaces,
		})
	}

	return config.Config{
		Contexts: convertToConfigContexts(contexts),
	}
}

// Internal types for conversion (to avoid circular dependencies)
type contextEntry struct {
	Name       string
	Namespaces []namespaceEntry
}

type namespaceEntry struct {
	Name     string
	Forwards []forwardEntry
}

type forwardEntry struct {
	Resource  string `yaml:"resource"`
	Protocol  string `yaml:"protocol"`
	Port      int    `yaml:"port"`
	LocalPort int    `yaml:"localPort"`
	Alias     string `yaml:"alias,omitempty"`
}

// Convert internal types to config package types
func convertToConfigContexts(contexts []contextEntry) []config.Context {
	var result []config.Context
	for _, ctx := range contexts {
		var namespaces []config.Namespace
		for _, ns := range ctx.Namespaces {
			var forwards []config.Forward
			for _, fwd := range ns.Forwards {
				forwards = append(forwards, config.Forward{
					Resource:  fwd.Resource,
					Protocol:  fwd.Protocol,
					Port:      fwd.Port,
					LocalPort: fwd.LocalPort,
					Alias:     fwd.Alias,
				})
			}
			namespaces = append(namespaces, config.Namespace{
				Name:     ns.Name,
				Forwards: forwards,
			})
		}
		result = append(result, config.Context{
			Name:       ctx.Name,
			Namespaces: namespaces,
		})
	}
	return result
}