package stage

import (
	"context"
	"fmt"
	"path/filepath"

	"gitea.maximumdirect.net/eric/narratio/internal/adapters/notify"
	"gitea.maximumdirect.net/eric/narratio/internal/adapters/storage"
	"gitea.maximumdirect.net/eric/narratio/internal/artifacts"
	"gitea.maximumdirect.net/eric/narratio/internal/manifest"
)

const placeholderMessage = "placeholder stage: no real work executed"

type placeholderStage struct {
	name string
}

func (s placeholderStage) Name() string { return s.name }

func (s placeholderStage) Declares() IODecl {
	return IODecl{
		Inputs:  []artifacts.Ref{{Kind: "artifact", Category: "input", RelativePath: s.name + ".input.placeholder"}},
		Outputs: []artifacts.Ref{{Kind: "artifact", Category: "output", RelativePath: s.name + ".output.placeholder"}},
	}
}

func (s placeholderStage) Run(ctx context.Context, env *Env, m *manifest.Manifest) (*StageResult, error) {
	result := &StageResult{
		Metadata: map[string]any{
			"placeholder": true,
			"stage":       s.name,
			"message":     placeholderMessage,
		},
	}

	if env == nil || env.Config == nil || env.ArtifactStore == nil {
		return result, nil
	}

	sessionID := m.SessionID
	if sessionID == "" && env.Config.Session != nil {
		sessionID = env.Config.Session.SessionID
	}
	if sessionID == "" {
		return result, nil
	}

	paths := env.ArtifactStore.SessionPaths(sessionID)

	switch s.name {
	case "archive":
		if env.Storage != nil {
			req := storage.ArchiveRequest{
				SessionID:    sessionID,
				ManifestPath: paths.ManifestPath,
				Items: []storage.ArchiveItem{{
					Kind:      "artifact",
					LocalPath: filepath.Join(paths.ArtifactsDir, "session-log.md"),
					RemoteKey: "sessions/" + sessionID + "/artifacts/session-log.md",
				}},
			}
			_, err := env.Storage.Archive(ctx, req)
			if err != nil {
				return nil, fmt.Errorf("placeholder archive adapter call failed: %w", err)
			}
		}
	case "notify":
		if env.Notifier != nil {
			req := notify.SendRequest{
				Subject: "narratio placeholder run complete",
				Body:    "placeholder stage execution finished",
				Metadata: map[string]string{
					"session_id": sessionID,
				},
			}
			_, err := env.Notifier.Send(ctx, req)
			if err != nil {
				return nil, fmt.Errorf("placeholder notify adapter call failed: %w", err)
			}
		}
	}

	return result, nil
}

// All returns the canonical ordered stage list for full pipeline execution.
func All() []Stage {
	return []Stage{
		prepareStage{},
		transcribeStage{},
		placeholderStage{name: "normalize"},
		mergeStage{},
		polishStage{},
		analyzeStage{},
		placeholderStage{name: "archive"},
		placeholderStage{name: "notify"},
	}
}

// Select returns one stage by exact name from the canonical stage set.
func Select(name string) (Stage, error) {
	for _, s := range All() {
		if s.Name() == name {
			return s, nil
		}
	}
	return nil, fmt.Errorf("unknown stage %q", name)
}