package config

import "time"

const (
	DefaultConfigPath = "./configs/dev.yaml"
	DefaultSource     = "mcp"
)

type Config struct {
	Server        ServerConfig        `yaml:"server"`
	MCP           MCPConfig           `yaml:"mcp"`
	Auth          AuthConfig          `yaml:"auth"`
	Database      DatabaseConfig      `yaml:"database"`
	AI            AIConfig            `yaml:"ai"`
	Capture       CaptureConfig       `yaml:"capture"`
	Search        SearchConfig        `yaml:"search"`
	Logging       LoggingConfig       `yaml:"logging"`
	Observability ObservabilityConfig `yaml:"observability"`
	Backfill      BackfillConfig      `yaml:"backfill"`
	MetadataRetry MetadataRetryConfig `yaml:"metadata_retry"`
}

type ServerConfig struct {
	Host           string        `yaml:"host"`
	Port           int           `yaml:"port"`
	ReadTimeout    time.Duration `yaml:"read_timeout"`
	WriteTimeout   time.Duration `yaml:"write_timeout"`
	IdleTimeout    time.Duration `yaml:"idle_timeout"`
	AllowedOrigins []string      `yaml:"allowed_origins"`
}

type MCPConfig struct {
	Path       string `yaml:"path"`
	ServerName string `yaml:"server_name"`
	Version    string `yaml:"version"`
	Transport  string `yaml:"transport"`
}

type AuthConfig struct {
	HeaderName      string      `yaml:"header_name"`
	QueryParam      string      `yaml:"query_param"`
	AllowQueryParam bool        `yaml:"allow_query_param"`
	Keys            []APIKey    `yaml:"keys"`
	OAuth           OAuthConfig `yaml:"oauth"`
}

type APIKey struct {
	ID          string `yaml:"id"`
	Value       string `yaml:"value"`
	Description string `yaml:"description"`
}

type OAuthConfig struct {
	Clients []OAuthClient `yaml:"clients"`
}

type OAuthClient struct {
	ID           string `yaml:"id"`
	ClientID     string `yaml:"client_id"`
	ClientSecret string `yaml:"client_secret"`
	Description  string `yaml:"description"`
}

type DatabaseConfig struct {
	URL             string        `yaml:"url"`
	MaxConns        int32         `yaml:"max_conns"`
	MinConns        int32         `yaml:"min_conns"`
	MaxConnLifetime time.Duration `yaml:"max_conn_lifetime"`
	MaxConnIdleTime time.Duration `yaml:"max_conn_idle_time"`
}

type AIConfig struct {
	Provider   string             `yaml:"provider"`
	Embeddings AIEmbeddingConfig  `yaml:"embeddings"`
	Metadata   AIMetadataConfig   `yaml:"metadata"`
	LiteLLM    LiteLLMConfig      `yaml:"litellm"`
	Ollama     OllamaConfig       `yaml:"ollama"`
	OpenRouter OpenRouterAIConfig `yaml:"openrouter"`
}

type AIEmbeddingConfig struct {
	Model      string `yaml:"model"`
	Dimensions int    `yaml:"dimensions"`
}

type AIMetadataConfig struct {
	Model            string        `yaml:"model"`
	FallbackModels   []string      `yaml:"fallback_models"`
	FallbackModel    string        `yaml:"fallback_model"` // legacy single fallback
	Temperature      float64       `yaml:"temperature"`
	LogConversations bool          `yaml:"log_conversations"`
	Timeout          time.Duration `yaml:"timeout"`
}

type LiteLLMConfig struct {
	BaseURL                string            `yaml:"base_url"`
	APIKey                 string            `yaml:"api_key"`
	UseResponsesAPI        bool              `yaml:"use_responses_api"`
	RequestHeaders         map[string]string `yaml:"request_headers"`
	EmbeddingModel         string            `yaml:"embedding_model"`
	MetadataModel          string            `yaml:"metadata_model"`
	FallbackMetadataModels []string          `yaml:"fallback_metadata_models"`
	FallbackMetadataModel  string            `yaml:"fallback_metadata_model"` // legacy single fallback
}

type OllamaConfig struct {
	BaseURL        string            `yaml:"base_url"`
	APIKey         string            `yaml:"api_key"`
	RequestHeaders map[string]string `yaml:"request_headers"`
}

type OpenRouterAIConfig struct {
	BaseURL      string            `yaml:"base_url"`
	APIKey       string            `yaml:"api_key"`
	AppName      string            `yaml:"app_name"`
	SiteURL      string            `yaml:"site_url"`
	ExtraHeaders map[string]string `yaml:"extra_headers"`
}

type CaptureConfig struct {
	Source           string                 `yaml:"source"`
	MetadataDefaults CaptureMetadataDefault `yaml:"metadata_defaults"`
}

type CaptureMetadataDefault struct {
	Type          string `yaml:"type"`
	TopicFallback string `yaml:"topic_fallback"`
}

type SearchConfig struct {
	DefaultLimit     int     `yaml:"default_limit"`
	DefaultThreshold float64 `yaml:"default_threshold"`
	MaxLimit         int     `yaml:"max_limit"`
}

type LoggingConfig struct {
	Level  string `yaml:"level"`
	Format string `yaml:"format"`
}

type ObservabilityConfig struct {
	MetricsEnabled bool `yaml:"metrics_enabled"`
	PprofEnabled   bool `yaml:"pprof_enabled"`
}

type BackfillConfig struct {
	Enabled         bool          `yaml:"enabled"`
	RunOnStartup    bool          `yaml:"run_on_startup"`
	Interval        time.Duration `yaml:"interval"`
	BatchSize       int           `yaml:"batch_size"`
	MaxPerRun       int           `yaml:"max_per_run"`
	IncludeArchived bool          `yaml:"include_archived"`
}

type MetadataRetryConfig struct {
	Enabled         bool          `yaml:"enabled"`
	RunOnStartup    bool          `yaml:"run_on_startup"`
	Interval        time.Duration `yaml:"interval"`
	MaxPerRun       int           `yaml:"max_per_run"`
	IncludeArchived bool          `yaml:"include_archived"`
}

func (c AIMetadataConfig) EffectiveFallbackModels() []string {
	models := make([]string, 0, len(c.FallbackModels)+1)
	for _, model := range c.FallbackModels {
		if model != "" {
			models = append(models, model)
		}
	}
	if c.FallbackModel != "" {
		models = append(models, c.FallbackModel)
	}
	return dedupeNonEmpty(models)
}

func (c LiteLLMConfig) EffectiveFallbackMetadataModels() []string {
	models := make([]string, 0, len(c.FallbackMetadataModels)+1)
	for _, model := range c.FallbackMetadataModels {
		if model != "" {
			models = append(models, model)
		}
	}
	if c.FallbackMetadataModel != "" {
		models = append(models, c.FallbackMetadataModel)
	}
	return dedupeNonEmpty(models)
}

func dedupeNonEmpty(values []string) []string {
	seen := make(map[string]struct{}, len(values))
	out := make([]string, 0, len(values))
	for _, value := range values {
		if value == "" {
			continue
		}
		if _, ok := seen[value]; ok {
			continue
		}
		seen[value] = struct{}{}
		out = append(out, value)
	}
	return out
}