package providers

import (
	"fmt"

	"gopkg.in/yaml.v3"
)

// Provider represents a single API key provider definition loaded from YAML.
type Provider struct {
	FormatVersion int        `yaml:"format_version"`
	Name          string     `yaml:"name"`
	DisplayName   string     `yaml:"display_name"`
	Tier          int        `yaml:"tier"`
	LastVerified  string     `yaml:"last_verified"`
	Keywords      []string   `yaml:"keywords"`
	Patterns      []Pattern  `yaml:"patterns"`
	Verify        VerifySpec `yaml:"verify"`
}

// Pattern defines a single regex pattern for API key detection.
type Pattern struct {
	Regex      string  `yaml:"regex"`
	EntropyMin float64 `yaml:"entropy_min"`
	Confidence string  `yaml:"confidence"`
}

// VerifySpec defines how to verify a key is live (used by Phase 5 verification engine).
type VerifySpec struct {
	Method        string            `yaml:"method"`
	URL           string            `yaml:"url"`
	Headers       map[string]string `yaml:"headers"`
	ValidStatus   []int             `yaml:"valid_status"`
	InvalidStatus []int             `yaml:"invalid_status"`
}

// RegistryStats holds aggregate statistics about loaded providers.
type RegistryStats struct {
	Total        int
	ByTier       map[int]int
	ByConfidence map[string]int
}

// UnmarshalYAML implements yaml.Unmarshaler with schema validation (satisfies PROV-10).
func (p *Provider) UnmarshalYAML(value *yaml.Node) error {
	// Use a type alias to avoid infinite recursion
	type ProviderAlias Provider
	var alias ProviderAlias
	if err := value.Decode(&alias); err != nil {
		return err
	}
	if alias.FormatVersion < 1 {
		return fmt.Errorf("provider %q: format_version must be >= 1 (got %d)", alias.Name, alias.FormatVersion)
	}
	if alias.LastVerified == "" {
		return fmt.Errorf("provider %q: last_verified is required", alias.Name)
	}
	validConfidences := map[string]bool{"high": true, "medium": true, "low": true, "": true}
	for _, pat := range alias.Patterns {
		if !validConfidences[pat.Confidence] {
			return fmt.Errorf("provider %q: pattern confidence %q must be high, medium, or low", alias.Name, pat.Confidence)
		}
	}
	*p = Provider(alias)
	return nil
}