package artifacts

import (
	"fmt"
	"sort"
	"strings"

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

const (
	ArtifactProvenanceGeneratedCurrentAnalyzeRun = "generated.current_analyze_run"
	ArtifactProvenanceDisabledFromDisk           = "filesystem.disabled_artifact_output"
)

// ConfiguredArtifactDefinition describes one configured analyze artifact.
type ConfiguredArtifactDefinition struct {
	Enabled    bool
	OutputPath string
}

// CatalogEntry is one runtime catalog entry resolved by source ID.
type CatalogEntry struct {
	SourceID         string
	ConfiguredKey    string
	CanonicalRelPath string
	ProducerStage    string
	OutputKind       string
	Planned          bool
	Executable       bool
	Available        bool
	Path             string
	Provenance       string
}

// ArtifactCatalog tracks built-in and configured artifact definitions and runtime state.
type ArtifactCatalog struct {
	entries         map[string]CatalogEntry
	configuredIndex map[string]string
}

// NewArtifactCatalog returns an empty runtime artifact catalog.
func NewArtifactCatalog() *ArtifactCatalog {
	return &ArtifactCatalog{
		entries:         map[string]CatalogEntry{},
		configuredIndex: map[string]string{},
	}
}

// ConfiguredArtifactSourceID converts a configured artifact key into canonical source ID.
func ConfiguredArtifactSourceID(key string) string {
	return artifactpolicy.ConfiguredSourceID(key)
}

// RegisterBuiltIns registers built-in source definitions used by runtime artifact resolution.
func (c *ArtifactCatalog) RegisterBuiltIns() error {
	for _, id := range runtimeBuiltInArtifactIDs() {
		spec, ok := artifactRegistry[id]
		if !ok {
			return fmt.Errorf("register built-ins: source %q not found in artifact registry", id)
		}
		if err := c.addEntry(CatalogEntry{
			SourceID:         spec.ID,
			CanonicalRelPath: spec.CanonicalRelPath,
			ProducerStage:    spec.ProducerStage,
			OutputKind:       spec.OutputKind,
			Planned:          true,
		}); err != nil {
			return fmt.Errorf("register built-ins: %w", err)
		}
	}
	return nil
}

// RegisterConfiguredArtifacts registers configured artifacts and applies executable selection.
func (c *ArtifactCatalog) RegisterConfiguredArtifacts(
	configured map[string]ConfiguredArtifactDefinition,
	selected []string,
) error {
	keys := make([]string, 0, len(configured))
	for key := range configured {
		keys = append(keys, key)
	}
	sort.Strings(keys)

	selectedSet := map[string]struct{}{}
	for _, key := range selected {
		trimmed := strings.TrimSpace(key)
		if trimmed == "" {
			return fmt.Errorf("selected artifact keys must be non-empty")
		}
		selectedSet[trimmed] = struct{}{}
	}

	for _, key := range keys {
		trimmed := strings.TrimSpace(key)
		if trimmed == "" {
			return fmt.Errorf("configured artifact keys must be non-empty")
		}
		def := configured[key]
		sourceID := ConfiguredArtifactSourceID(trimmed)
		if _, exists := c.configuredIndex[trimmed]; exists {
			return fmt.Errorf("duplicate configured artifact key %q", trimmed)
		}

		executable := def.Enabled
		if len(selectedSet) > 0 {
			_, executable = selectedSet[trimmed]
		}

		if err := c.addEntry(CatalogEntry{
			SourceID:         sourceID,
			ConfiguredKey:    trimmed,
			CanonicalRelPath: strings.TrimSpace(def.OutputPath),
			ProducerStage:    "analyze",
			OutputKind:       "scriptorium_artifact",
			Planned:          true,
			Executable:       executable,
		}); err != nil {
			return fmt.Errorf("register configured artifact %q: %w", trimmed, err)
		}
		c.configuredIndex[trimmed] = sourceID
	}

	if len(selectedSet) > 0 {
		for key := range selectedSet {
			if _, ok := c.configuredIndex[key]; !ok {
				return fmt.Errorf("selected artifact %q is not configured", key)
			}
		}
	}

	return nil
}

// Lookup returns one catalog entry by source ID.
func (c *ArtifactCatalog) Lookup(sourceID string) (CatalogEntry, bool) {
	if c == nil {
		return CatalogEntry{}, false
	}
	entry, ok := c.entries[strings.TrimSpace(sourceID)]
	return entry, ok
}

// SourceIDForConfiguredKey returns canonical source ID for one configured key.
func (c *ArtifactCatalog) SourceIDForConfiguredKey(key string) (string, bool) {
	if c == nil {
		return "", false
	}
	sourceID, ok := c.configuredIndex[strings.TrimSpace(key)]
	return sourceID, ok
}

// ListConfigured returns configured entries sorted by configured key.
func (c *ArtifactCatalog) ListConfigured() []CatalogEntry {
	if c == nil || len(c.configuredIndex) == 0 {
		return nil
	}
	keys := make([]string, 0, len(c.configuredIndex))
	for key := range c.configuredIndex {
		keys = append(keys, key)
	}
	sort.Strings(keys)
	out := make([]CatalogEntry, 0, len(keys))
	for _, key := range keys {
		sourceID := c.configuredIndex[key]
		out = append(out, c.entries[sourceID])
	}
	return out
}

// MarkAvailableGenerated marks one source as available in current analyze execution.
func (c *ArtifactCatalog) MarkAvailableGenerated(sourceID, path string) error {
	return c.markAvailable(sourceID, path, ArtifactProvenanceGeneratedCurrentAnalyzeRun)
}

// MarkAvailableFromDisk marks one source as available from disabled artifact on disk.
func (c *ArtifactCatalog) MarkAvailableFromDisk(sourceID, path string) error {
	return c.markAvailable(sourceID, path, ArtifactProvenanceDisabledFromDisk)
}

func (c *ArtifactCatalog) markAvailable(sourceID, path, provenance string) error {
	if c == nil {
		return fmt.Errorf("artifact catalog is nil")
	}
	normalizedID := strings.TrimSpace(sourceID)
	entry, ok := c.entries[normalizedID]
	if !ok {
		return fmt.Errorf("unknown artifact source %q", sourceID)
	}
	trimmedPath := strings.TrimSpace(path)
	if trimmedPath == "" {
		return fmt.Errorf("artifact path is required")
	}
	entry.Available = true
	entry.Path = trimmedPath
	entry.Provenance = provenance
	c.entries[normalizedID] = entry
	return nil
}

func (c *ArtifactCatalog) addEntry(entry CatalogEntry) error {
	if c == nil {
		return fmt.Errorf("artifact catalog is nil")
	}
	sourceID := strings.TrimSpace(entry.SourceID)
	if sourceID == "" {
		return fmt.Errorf("source id is required")
	}
	if _, exists := c.entries[sourceID]; exists {
		return fmt.Errorf("source id %q is already registered", sourceID)
	}
	entry.SourceID = sourceID
	c.entries[sourceID] = entry
	return nil
}

func runtimeBuiltInArtifactIDs() []string {
	return []string{
		ArtifactTranscriptBase,
		ArtifactTranscriptPolished,
		ArtifactTranscriptFinal,
		ArtifactTranscriptFinalTrimmed,
		ArtifactBoundsSession,
	}
}