package config

import (
	"fmt"
	"io/ioutil"
	"os"
	"strings"
	"time"

	"gopkg.in/yaml.v2"
)

// SecurityConfig holds cluster security and election configuration
type SecurityConfig struct {
	// Admin key sharing
	AdminKeyShares  ShamirShare    `yaml:"admin_key_shares" json:"admin_key_shares"`
	ElectionConfig  ElectionConfig `yaml:"election_config" json:"election_config"`
	
	// Key management
	KeyRotationDays int    `yaml:"key_rotation_days,omitempty" json:"key_rotation_days,omitempty"`
	AuditLogging    bool   `yaml:"audit_logging" json:"audit_logging"`
	AuditPath       string `yaml:"audit_path,omitempty" json:"audit_path,omitempty"`
}

// Config represents the complete configuration for a Bzzz agent
type Config struct {
	HiveAPI  HiveAPIConfig  `yaml:"hive_api"`
	Agent    AgentConfig    `yaml:"agent"`
	GitHub   GitHubConfig   `yaml:"github"`
	P2P      P2PConfig      `yaml:"p2p"`
	Logging  LoggingConfig  `yaml:"logging"`
	HCFS     HCFSConfig     `yaml:"hcfs"`
	Slurp    SlurpConfig    `yaml:"slurp"`
	V2       V2Config       `yaml:"v2"`   // BZZZ v2 protocol settings
	UCXL     UCXLConfig     `yaml:"ucxl"` // UCXL protocol settings
	Security SecurityConfig `yaml:"security"` // Cluster security and elections
}

// HiveAPIConfig holds Hive system integration settings
type HiveAPIConfig struct {
	BaseURL    string        `yaml:"base_url"`
	APIKey     string        `yaml:"api_key"`
	Timeout    time.Duration `yaml:"timeout"`
	RetryCount int           `yaml:"retry_count"`
}

// CollaborationConfig holds role-based collaboration settings
type CollaborationConfig struct {
	PreferredMessageTypes     []string          `yaml:"preferred_message_types"`
	AutoSubscribeToRoles      []string          `yaml:"auto_subscribe_to_roles"`
	AutoSubscribeToExpertise  []string          `yaml:"auto_subscribe_to_expertise"`
	ResponseTimeoutSeconds    int               `yaml:"response_timeout_seconds"`
	MaxCollaborationDepth     int               `yaml:"max_collaboration_depth"`
	EscalationThreshold       int               `yaml:"escalation_threshold"`
	CustomTopicSubscriptions  []string          `yaml:"custom_topic_subscriptions"`
}

// AgentConfig holds agent-specific configuration
type AgentConfig struct {
	ID                    string        `yaml:"id"`
	Capabilities          []string      `yaml:"capabilities"`
	PollInterval          time.Duration `yaml:"poll_interval"`
	MaxTasks              int           `yaml:"max_tasks"`
	Models                []string      `yaml:"models"`
	Specialization        string        `yaml:"specialization"`
	ModelSelectionWebhook string        `yaml:"model_selection_webhook"`
	DefaultReasoningModel string        `yaml:"default_reasoning_model"`
	SandboxImage          string        `yaml:"sandbox_image"`
	
	// Role-based configuration from Bees-AgenticWorkers
	Role         string            `yaml:"role"`
	SystemPrompt string            `yaml:"system_prompt"`
	ReportsTo    []string          `yaml:"reports_to"`
	Expertise    []string          `yaml:"expertise"`
	Deliverables []string          `yaml:"deliverables"`
	
	// Role-based collaboration settings
	CollaborationSettings CollaborationConfig `yaml:"collaboration"`
}

// GitHubConfig holds GitHub integration settings
type GitHubConfig struct {
	TokenFile    string        `yaml:"token_file"`
	UserAgent    string        `yaml:"user_agent"`
	Timeout      time.Duration `yaml:"timeout"`
	RateLimit    bool          `yaml:"rate_limit"`
	Assignee     string        `yaml:"assignee"`
}

// P2PConfig holds P2P networking configuration
type P2PConfig struct {
	ServiceTag       string        `yaml:"service_tag"`
	BzzzTopic        string        `yaml:"bzzz_topic"`
	HmmmTopic        string        `yaml:"hmmm_topic"`
	DiscoveryTimeout time.Duration `yaml:"discovery_timeout"`
	
	// Human escalation settings
	EscalationWebhook       string   `yaml:"escalation_webhook"`
	EscalationKeywords      []string `yaml:"escalation_keywords"`
	ConversationLimit       int      `yaml:"conversation_limit"`
}

// LoggingConfig holds logging configuration
type LoggingConfig struct {
	Level      string `yaml:"level"`
	Format     string `yaml:"format"`
	Output     string `yaml:"output"`
	Structured bool   `yaml:"structured"`
}

// V2Config holds BZZZ v2 protocol configuration
type V2Config struct {
	// Enable v2 protocol features
	Enabled bool `yaml:"enabled" json:"enabled"`
	
	// Protocol version
	ProtocolVersion string `yaml:"protocol_version" json:"protocol_version"`
	
	// URI resolution settings
	URIResolution URIResolutionConfig `yaml:"uri_resolution" json:"uri_resolution"`
	
	// DHT settings
	DHT DHTConfig `yaml:"dht" json:"dht"`
	
	// Semantic addressing
	SemanticAddressing SemanticAddressingConfig `yaml:"semantic_addressing" json:"semantic_addressing"`
	
	// Feature flags
	FeatureFlags map[string]bool `yaml:"feature_flags" json:"feature_flags"`
}

// URIResolutionConfig holds URI resolution settings
type URIResolutionConfig struct {
	CacheTTL          time.Duration `yaml:"cache_ttl" json:"cache_ttl"`
	MaxPeersPerResult int           `yaml:"max_peers_per_result" json:"max_peers_per_result"`
	DefaultStrategy   string        `yaml:"default_strategy" json:"default_strategy"`
	ResolutionTimeout time.Duration `yaml:"resolution_timeout" json:"resolution_timeout"`
}

// DHTConfig holds DHT-specific configuration
type DHTConfig struct {
	Enabled           bool          `yaml:"enabled" json:"enabled"`
	BootstrapPeers    []string      `yaml:"bootstrap_peers" json:"bootstrap_peers"`
	Mode              string        `yaml:"mode" json:"mode"` // "client", "server", "auto"
	ProtocolPrefix    string        `yaml:"protocol_prefix" json:"protocol_prefix"`
	BootstrapTimeout  time.Duration `yaml:"bootstrap_timeout" json:"bootstrap_timeout"`
	DiscoveryInterval time.Duration `yaml:"discovery_interval" json:"discovery_interval"`
	AutoBootstrap     bool          `yaml:"auto_bootstrap" json:"auto_bootstrap"`
}

// SemanticAddressingConfig holds semantic addressing settings
type SemanticAddressingConfig struct {
	EnableWildcards     bool   `yaml:"enable_wildcards" json:"enable_wildcards"`
	DefaultAgent        string `yaml:"default_agent" json:"default_agent"`
	DefaultRole         string `yaml:"default_role" json:"default_role"`
	DefaultProject      string `yaml:"default_project" json:"default_project"`
	EnableRoleHierarchy bool   `yaml:"enable_role_hierarchy" json:"enable_role_hierarchy"`
}

// UCXLConfig holds UCXL protocol configuration
type UCXLConfig struct {
	// Enable UCXL protocol
	Enabled bool `yaml:"enabled" json:"enabled"`
	
	// UCXI server configuration
	Server UCXIServerConfig `yaml:"server" json:"server"`
	
	// Address resolution settings
	Resolution UCXLResolutionConfig `yaml:"resolution" json:"resolution"`
	
	// Storage settings
	Storage UCXLStorageConfig `yaml:"storage" json:"storage"`
	
	// P2P integration settings
	P2PIntegration UCXLP2PConfig `yaml:"p2p_integration" json:"p2p_integration"`
}

// UCXIServerConfig holds UCXI server settings
type UCXIServerConfig struct {
	Port     int    `yaml:"port" json:"port"`
	BasePath string `yaml:"base_path" json:"base_path"`
	Enabled  bool   `yaml:"enabled" json:"enabled"`
}

// UCXLResolutionConfig holds address resolution settings
type UCXLResolutionConfig struct {
	CacheTTL        time.Duration `yaml:"cache_ttl" json:"cache_ttl"`
	EnableWildcards bool          `yaml:"enable_wildcards" json:"enable_wildcards"`
	MaxResults      int           `yaml:"max_results" json:"max_results"`
}

// UCXLStorageConfig holds storage settings
type UCXLStorageConfig struct {
	Type      string `yaml:"type" json:"type"` // "filesystem", "memory"
	Directory string `yaml:"directory" json:"directory"`
	MaxSize   int64  `yaml:"max_size" json:"max_size"` // in bytes
}

// UCXLP2PConfig holds P2P integration settings
type UCXLP2PConfig struct {
	EnableAnnouncement bool `yaml:"enable_announcement" json:"enable_announcement"`
	EnableDiscovery    bool `yaml:"enable_discovery" json:"enable_discovery"`
	AnnouncementTopic  string `yaml:"announcement_topic" json:"announcement_topic"`
	DiscoveryTimeout   time.Duration `yaml:"discovery_timeout" json:"discovery_timeout"`
}

// HCFSConfig holds HCFS integration configuration
type HCFSConfig struct {
	// API settings
	APIURL     string        `yaml:"api_url" json:"api_url"`
	APITimeout time.Duration `yaml:"api_timeout" json:"api_timeout"`
	
	// Workspace settings
	MountPath        string        `yaml:"mount_path" json:"mount_path"`
	WorkspaceTimeout time.Duration `yaml:"workspace_timeout" json:"workspace_timeout"`
	
	// FUSE settings
	FUSEEnabled    bool   `yaml:"fuse_enabled" json:"fuse_enabled"`
	FUSEMountPoint string `yaml:"fuse_mount_point" json:"fuse_mount_point"`
	
	// Cleanup settings
	IdleCleanupInterval time.Duration `yaml:"idle_cleanup_interval" json:"idle_cleanup_interval"`
	MaxIdleTime         time.Duration `yaml:"max_idle_time" json:"max_idle_time"`
	
	// Storage settings
	StoreArtifacts    bool `yaml:"store_artifacts" json:"store_artifacts"`
	CompressArtifacts bool `yaml:"compress_artifacts" json:"compress_artifacts"`
	
	// Enable/disable HCFS integration
	Enabled bool `yaml:"enabled" json:"enabled"`
}

// LoadConfig loads configuration from file, environment variables, and defaults
func LoadConfig(configPath string) (*Config, error) {
	// Start with defaults
	config := getDefaultConfig()
	
	// Load from file if it exists
	if configPath != "" && fileExists(configPath) {
		if err := loadFromFile(config, configPath); err != nil {
			return nil, fmt.Errorf("failed to load config file: %w", err)
		}
	}
	
	// Override with environment variables
	if err := loadFromEnv(config); err != nil {
		return nil, fmt.Errorf("failed to load environment variables: %w", err)
	}
	
	// Validate configuration
	if err := validateConfig(config); err != nil {
		return nil, fmt.Errorf("invalid configuration: %w", err)
	}
	
	return config, nil
}

// getDefaultConfig returns the default configuration
func getDefaultConfig() *Config {
	return &Config{
		HiveAPI: HiveAPIConfig{
			BaseURL:    "https://hive.home.deepblack.cloud",
			Timeout:    30 * time.Second,
			RetryCount: 3,
		},
		Agent: AgentConfig{
			Capabilities:          []string{"general", "reasoning", "task-coordination"},
			PollInterval:          30 * time.Second,
			MaxTasks:              3,
			Models:                []string{"phi3", "llama3.1"},
			Specialization:        "general_developer",
			ModelSelectionWebhook: "https://n8n.home.deepblack.cloud/webhook/model-selection",
			DefaultReasoningModel: "phi3",
			SandboxImage:          "registry.home.deepblack.cloud/tony/bzzz-sandbox:latest",
		},
		GitHub: GitHubConfig{
			TokenFile: "/home/tony/chorus/business/secrets/gh-token",
			UserAgent: "Bzzz-P2P-Agent/1.0",
			Timeout:   30 * time.Second,
			RateLimit: true,
			Assignee:  "anthonyrawlins",
		},
		P2P: P2PConfig{
			ServiceTag:              "bzzz-peer-discovery",
			BzzzTopic:               "bzzz/coordination/v1",
			HmmmTopic:              "hmmm/meta-discussion/v1",
			DiscoveryTimeout:        10 * time.Second,
			EscalationWebhook:       "https://n8n.home.deepblack.cloud/webhook-test/human-escalation",
			EscalationKeywords:      []string{"stuck", "help", "human", "escalate", "clarification needed", "manual intervention"},
			ConversationLimit:       10,
		},
		Logging: LoggingConfig{
			Level:      "info",
			Format:     "text",
			Output:     "stdout",
			Structured: false,
		},
		HCFS: HCFSConfig{
			APIURL:              "http://localhost:8000",
			APITimeout:          30 * time.Second,
			MountPath:           "/tmp/hcfs-workspaces",
			WorkspaceTimeout:    2 * time.Hour,
			FUSEEnabled:         false,
			FUSEMountPoint:      "/mnt/hcfs",
			IdleCleanupInterval: 15 * time.Minute,
			MaxIdleTime:         1 * time.Hour,
			StoreArtifacts:      true,
			CompressArtifacts:   false,
			Enabled:             true,
		},
		Slurp: GetDefaultSlurpConfig(),
		UCXL: UCXLConfig{
			Enabled: false, // Disabled by default
			Server: UCXIServerConfig{
				Port:     8081,
				BasePath: "/bzzz",
				Enabled:  true,
			},
			Resolution: UCXLResolutionConfig{
				CacheTTL:        5 * time.Minute,
				EnableWildcards: true,
				MaxResults:      50,
			},
			Storage: UCXLStorageConfig{
				Type:      "filesystem",
				Directory: "/tmp/bzzz-ucxl-storage",
				MaxSize:   100 * 1024 * 1024, // 100MB
			},
			P2PIntegration: UCXLP2PConfig{
				EnableAnnouncement: true,
				EnableDiscovery:    true,
				AnnouncementTopic:  "bzzz/ucxl/announcement/v1",
				DiscoveryTimeout:   30 * time.Second,
			},
		},
		Security: SecurityConfig{
			AdminKeyShares: ShamirShare{
				Threshold:   3,
				TotalShares: 5,
			},
			ElectionConfig: ElectionConfig{
				HeartbeatTimeout:     5 * time.Second,
				DiscoveryTimeout:     30 * time.Second,
				ElectionTimeout:      15 * time.Second,
				MaxDiscoveryAttempts: 6,
				DiscoveryBackoff:     5 * time.Second,
				MinimumQuorum:        3,
				ConsensusAlgorithm:   "raft",
				SplitBrainDetection:  true,
				ConflictResolution:   "highest_uptime",
			},
			KeyRotationDays: 90,
			AuditLogging:    true,
			AuditPath:       ".bzzz/security-audit.log",
		},
		V2: V2Config{
			Enabled:         false, // Disabled by default for backward compatibility
			ProtocolVersion: "2.0.0",
			URIResolution: URIResolutionConfig{
				CacheTTL:          5 * time.Minute,
				MaxPeersPerResult: 5,
				DefaultStrategy:   "best_match",
				ResolutionTimeout: 30 * time.Second,
			},
			DHT: DHTConfig{
				Enabled:           false, // Disabled by default
				BootstrapPeers:    []string{},
				Mode:              "auto",
				ProtocolPrefix:    "/bzzz",
				BootstrapTimeout:  30 * time.Second,
				DiscoveryInterval: 60 * time.Second,
				AutoBootstrap:     false,
			},
			SemanticAddressing: SemanticAddressingConfig{
				EnableWildcards:     true,
				DefaultAgent:        "any",
				DefaultRole:         "any",
				DefaultProject:      "any",
				EnableRoleHierarchy: true,
			},
			FeatureFlags: map[string]bool{
				"uri_protocol":        false,
				"semantic_addressing": false,
				"dht_discovery":      false,
				"advanced_resolution": false,
			},
		},
	}
}

// loadFromFile loads configuration from a YAML file
func loadFromFile(config *Config, filePath string) error {
	data, err := ioutil.ReadFile(filePath)
	if err != nil {
		return fmt.Errorf("failed to read config file: %w", err)
	}
	
	if err := yaml.Unmarshal(data, config); err != nil {
		return fmt.Errorf("failed to parse YAML config: %w", err)
	}
	
	return nil
}

// loadFromEnv loads configuration from environment variables
func loadFromEnv(config *Config) error {
	// Hive API configuration
	if url := os.Getenv("BZZZ_HIVE_API_URL"); url != "" {
		config.HiveAPI.BaseURL = url
	}
	if apiKey := os.Getenv("BZZZ_HIVE_API_KEY"); apiKey != "" {
		config.HiveAPI.APIKey = apiKey
	}
	
	// Agent configuration
	if agentID := os.Getenv("BZZZ_AGENT_ID"); agentID != "" {
		config.Agent.ID = agentID
	}
	if capabilities := os.Getenv("BZZZ_AGENT_CAPABILITIES"); capabilities != "" {
		config.Agent.Capabilities = strings.Split(capabilities, ",")
	}
	if specialization := os.Getenv("BZZZ_AGENT_SPECIALIZATION"); specialization != "" {
		config.Agent.Specialization = specialization
	}
	if modelWebhook := os.Getenv("BZZZ_MODEL_SELECTION_WEBHOOK"); modelWebhook != "" {
		config.Agent.ModelSelectionWebhook = modelWebhook
	}
	
	// GitHub configuration
	if tokenFile := os.Getenv("BZZZ_GITHUB_TOKEN_FILE"); tokenFile != "" {
		config.GitHub.TokenFile = tokenFile
	}
	
	// P2P configuration
	if webhook := os.Getenv("BZZZ_ESCALATION_WEBHOOK"); webhook != "" {
		config.P2P.EscalationWebhook = webhook
	}
	
	// Logging configuration
	if level := os.Getenv("BZZZ_LOG_LEVEL"); level != "" {
		config.Logging.Level = level
	}
	
	// SLURP configuration
	if slurpURL := os.Getenv("BZZZ_SLURP_URL"); slurpURL != "" {
		config.Slurp.BaseURL = slurpURL
	}
	if slurpKey := os.Getenv("BZZZ_SLURP_API_KEY"); slurpKey != "" {
		config.Slurp.APIKey = slurpKey
	}
	if slurpEnabled := os.Getenv("BZZZ_SLURP_ENABLED"); slurpEnabled == "true" {
		config.Slurp.Enabled = true
	}
	
	// UCXL protocol configuration
	if ucxlEnabled := os.Getenv("BZZZ_UCXL_ENABLED"); ucxlEnabled == "true" {
		config.UCXL.Enabled = true
	}
	if ucxiPort := os.Getenv("BZZZ_UCXI_PORT"); ucxiPort != "" {
		// Would need strconv.Atoi but keeping simple for now
		// In production, add proper integer parsing
	}
	
	// V2 protocol configuration
	if v2Enabled := os.Getenv("BZZZ_V2_ENABLED"); v2Enabled == "true" {
		config.V2.Enabled = true
	}
	if dhtEnabled := os.Getenv("BZZZ_DHT_ENABLED"); dhtEnabled == "true" {
		config.V2.DHT.Enabled = true
	}
	if dhtMode := os.Getenv("BZZZ_DHT_MODE"); dhtMode != "" {
		config.V2.DHT.Mode = dhtMode
	}
	if bootstrapPeers := os.Getenv("BZZZ_DHT_BOOTSTRAP_PEERS"); bootstrapPeers != "" {
		config.V2.DHT.BootstrapPeers = strings.Split(bootstrapPeers, ",")
	}
	
	return nil
}

// validateConfig validates the configuration values
func validateConfig(config *Config) error {
	// Validate required fields
	if config.HiveAPI.BaseURL == "" {
		return fmt.Errorf("hive_api.base_url is required")
	}
	
	// Note: Agent.ID can be empty - it will be auto-generated from node ID in main.go
	
	if len(config.Agent.Capabilities) == 0 {
		return fmt.Errorf("agent.capabilities cannot be empty")
	}
	
	if config.Agent.PollInterval <= 0 {
		return fmt.Errorf("agent.poll_interval must be positive")
	}
	
	if config.Agent.MaxTasks <= 0 {
		return fmt.Errorf("agent.max_tasks must be positive")
	}
	
	// Validate GitHub token file exists if specified
	if config.GitHub.TokenFile != "" && !fileExists(config.GitHub.TokenFile) {
		return fmt.Errorf("github token file does not exist: %s", config.GitHub.TokenFile)
	}
	
	// Validate SLURP configuration
	if err := ValidateSlurpConfig(config.Slurp); err != nil {
		return fmt.Errorf("slurp configuration invalid: %w", err)
	}
	
	return nil
}

// SaveConfig saves the configuration to a YAML file
func SaveConfig(config *Config, filePath string) error {
	data, err := yaml.Marshal(config)
	if err != nil {
		return fmt.Errorf("failed to marshal config to YAML: %w", err)
	}
	
	if err := ioutil.WriteFile(filePath, data, 0644); err != nil {
		return fmt.Errorf("failed to write config file: %w", err)
	}
	
	return nil
}

// GetGitHubToken reads the GitHub token from the configured file
func (c *Config) GetGitHubToken() (string, error) {
	if c.GitHub.TokenFile == "" {
		return "", fmt.Errorf("no GitHub token file configured")
	}
	
	tokenBytes, err := ioutil.ReadFile(c.GitHub.TokenFile)
	if err != nil {
		return "", fmt.Errorf("failed to read GitHub token: %w", err)
	}
	
	return strings.TrimSpace(string(tokenBytes)), nil
}

// fileExists checks if a file exists
func fileExists(filePath string) bool {
	_, err := os.Stat(filePath)
	return err == nil
}

// GenerateDefaultConfigFile creates a default configuration file
func GenerateDefaultConfigFile(filePath string) error {
	config := getDefaultConfig()
	return SaveConfig(config, filePath)
}