package artifacts

import (
	"fmt"
	"sort"
	"strings"

	"gitea.maximumdirect.net/eric/narratio/internal/artifactpolicy"
	"gitea.maximumdirect.net/eric/narratio/internal/config"
)

// EffectiveArtifactSet is the resolved set of configured artifacts that an
// analyze invocation will execute.
type EffectiveArtifactSet struct {
	keys     []string
	resolved bool
}

// ResolveEffectiveArtifactSet applies an explicit artifact selection when one
// is supplied; otherwise it selects the configured enabled artifacts.
func ResolveEffectiveArtifactSet(
	configured map[string]ConfiguredArtifactDefinition,
	selected []string,
) (EffectiveArtifactSet, error) {
	configuredKeys := make(map[string]ConfiguredArtifactDefinition, len(configured))
	for key, definition := range configured {
		trimmed := strings.TrimSpace(key)
		if !artifactpolicy.IsConfiguredKey(trimmed) {
			return EffectiveArtifactSet{}, fmt.Errorf("configured artifact key %q must match ^[a-z][a-z0-9_]*$", key)
		}
		configuredKeys[trimmed] = definition
	}

	if len(selected) > 0 {
		set := make(map[string]struct{}, len(selected))
		for _, key := range selected {
			trimmed := strings.TrimSpace(key)
			if !artifactpolicy.IsConfiguredKey(trimmed) {
				return EffectiveArtifactSet{}, fmt.Errorf("selected artifact key %q must match ^[a-z][a-z0-9_]*$", key)
			}
			if _, ok := configuredKeys[trimmed]; !ok {
				return EffectiveArtifactSet{}, fmt.Errorf("selected artifact %q is not configured", trimmed)
			}
			set[trimmed] = struct{}{}
		}
		return newEffectiveArtifactSet(set), nil
	}

	set := make(map[string]struct{}, len(configuredKeys))
	for key, definition := range configuredKeys {
		if definition.Enabled {
			set[key] = struct{}{}
		}
	}
	return newEffectiveArtifactSet(set), nil
}

// ConfiguredArtifactDefinitions converts Scriptorium configuration into the
// definition form used by the runtime catalog.
func ConfiguredArtifactDefinitions(items map[string]config.ScriptoriumArtifactConfig) map[string]ConfiguredArtifactDefinition {
	if len(items) == 0 {
		return nil
	}
	definitions := make(map[string]ConfiguredArtifactDefinition, len(items))
	for key, item := range items {
		definitions[key] = ConfiguredArtifactDefinition{
			Enabled:    item.Enabled,
			OutputPath: item.OutputPath,
		}
	}
	return definitions
}

// Keys returns the selected configured artifact keys in deterministic order.
func (s EffectiveArtifactSet) Keys() []string {
	return append([]string(nil), s.keys...)
}

// Includes reports whether a configured artifact belongs to the effective set.
func (s EffectiveArtifactSet) Includes(key string) bool {
	trimmed := strings.TrimSpace(key)
	index := sort.SearchStrings(s.keys, trimmed)
	return index < len(s.keys) && s.keys[index] == trimmed
}

// Resolved reports whether the set was created by ResolveEffectiveArtifactSet.
func (s EffectiveArtifactSet) Resolved() bool {
	return s.resolved
}

func newEffectiveArtifactSet(set map[string]struct{}) EffectiveArtifactSet {
	keys := make([]string, 0, len(set))
	for key := range set {
		keys = append(keys, key)
	}
	sort.Strings(keys)
	return EffectiveArtifactSet{keys: keys, resolved: true}
}