package audita

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

	"gitea.maximumdirect.net/eric/narratio/internal/adapters/subprocess"
	"gitea.maximumdirect.net/eric/narratio/internal/fileops"
)

// NoopRunner is a deterministic no-op audita adapter.
type NoopRunner struct{}

// Run returns requested output path with placeholder metadata.
func (n *NoopRunner) Run(ctx context.Context, req PolishRequest) (PolishResult, error) {
	if err := ctx.Err(); err != nil {
		return PolishResult{}, err
	}
	if err := materializePlaceholders(req); err != nil {
		return PolishResult{}, err
	}
	return PolishResult{
		ProcessedTranscriptPath: req.OutputProcessedPath,
		ReportPath:              req.ReportPath,
		WorkDir:                 req.WorkDir,
		StdoutLogPath:           req.StdoutLogPath,
		StderrLogPath:           req.StderrLogPath,
		GeneratedConfigPath:     req.GeneratedConfigPath,
		Metadata:                map[string]any{"placeholder": true},
	}, nil
}

// FakeRunner captures polish requests and returns deterministic responses.
type FakeRunner struct {
	Requests []PolishRequest
	Err      error
	Result   PolishResult
}

// Run records request and returns configured response.
func (f *FakeRunner) Run(ctx context.Context, req PolishRequest) (PolishResult, error) {
	if err := ctx.Err(); err != nil {
		return PolishResult{}, err
	}
	f.Requests = append(f.Requests, req)
	if f.Err != nil {
		return PolishResult{}, f.Err
	}
	if err := materializePlaceholders(req); err != nil {
		return PolishResult{}, err
	}
	res := f.Result
	if res.ProcessedTranscriptPath == "" {
		res.ProcessedTranscriptPath = req.OutputProcessedPath
	}
	if res.ReportPath == "" {
		res.ReportPath = req.ReportPath
	}
	if res.WorkDir == "" {
		res.WorkDir = req.WorkDir
	}
	if res.StdoutLogPath == "" {
		res.StdoutLogPath = req.StdoutLogPath
	}
	if res.StderrLogPath == "" {
		res.StderrLogPath = req.StderrLogPath
	}
	if res.GeneratedConfigPath == "" {
		res.GeneratedConfigPath = req.GeneratedConfigPath
	}
	if res.Metadata == nil {
		res.Metadata = map[string]any{"fake": true}
	}
	return res, nil
}

func materializePlaceholders(req PolishRequest) error {
	if req.GeneratedConfigPath != "" {
		payload := map[string]any{
			"schema":                 "audita.generated.v1",
			"placeholder":            true,
			"merged_transcript_path": req.MergedTranscriptPath,
			"output_path":            req.OutputProcessedPath,
		}
		if err := subprocess.WriteYAMLAtomic(req.GeneratedConfigPath, payload, fileops.WorkspaceFileMode); err != nil {
			return fmt.Errorf("write generated config %q: %w", req.GeneratedConfigPath, err)
		}
	}
	if req.StdoutLogPath != "" {
		if err := subprocess.WriteFileAtomic(req.StdoutLogPath, []byte("audita noop/fake stdout placeholder\n"), fileops.WorkspaceFileMode); err != nil {
			return fmt.Errorf("write stdout log %q: %w", req.StdoutLogPath, err)
		}
	}
	if req.StderrLogPath != "" {
		if err := subprocess.WriteFileAtomic(req.StderrLogPath, []byte("audita noop/fake stderr placeholder\n"), fileops.WorkspaceFileMode); err != nil {
			return fmt.Errorf("write stderr log %q: %w", req.StderrLogPath, err)
		}
	}
	if err := writeJSONIfRequested(req.OutputProcessedPath, map[string]any{
		"schema":   "audita.processed.v1",
		"segments": []any{},
	}); err != nil {
		return err
	}
	if err := writeJSONIfRequested(req.ReportPath, map[string]any{
		"schema": "audita.report.v1",
		"steps":  []any{},
	}); err != nil {
		return err
	}
	return nil
}

func writeJSONIfRequested(path string, payload any) error {
	if path == "" {
		return nil
	}
	if err := fileops.EnsureWorkspaceDirectory(filepath.Dir(path)); err != nil {
		return fmt.Errorf("create parent directory %q: %w", filepath.Dir(path), err)
	}
	data, err := json.Marshal(payload)
	if err != nil {
		return fmt.Errorf("marshal placeholder json for %q: %w", path, err)
	}
	if err := subprocess.WriteFileAtomic(path, data, fileops.WorkspaceFileMode); err != nil {
		return fmt.Errorf("write placeholder json %q: %w", path, err)
	}
	return nil
}