package render

import (
	"context"
	"fmt"
	"os"

	"gitea.maximumdirect.net/eric/seriatim/internal/artifact"
	"gitea.maximumdirect.net/eric/seriatim/internal/config"
)

// Run executes artifact-level render orchestration.
func Run(ctx context.Context, cfg config.RenderConfig) error {
	if err := ctx.Err(); err != nil {
		return err
	}

	data, err := os.ReadFile(cfg.InputFile)
	if err != nil {
		return fmt.Errorf("read --input-file %q: %w", cfg.InputFile, err)
	}

	inputArtifact, err := artifact.ParseOutputArtifactJSON(data)
	if err != nil {
		return fmt.Errorf("--input-file %q: %w", cfg.InputFile, err)
	}

	model, err := FromOutputArtifact(inputArtifact)
	if err != nil {
		return fmt.Errorf("normalize artifact for render: %w", err)
	}

	registry := NewRegistry()
	renderer, err := registry.Resolve(cfg.Format)
	if err != nil {
		return err
	}

	rendered, err := renderer.Render(model, Options{
		Title:             cfg.Title,
		IncludeTimestamps: cfg.IncludeTimestamps,
		IncludeSegmentIDs: cfg.IncludeSegmentIDs,
		IncludeMetadata:   cfg.IncludeMetadata,
	})
	if err != nil {
		return fmt.Errorf("render %q output: %w", cfg.Format, err)
	}

	if err := writeFile(cfg.OutputFile, rendered); err != nil {
		return fmt.Errorf("write --output-file %q: %w", cfg.OutputFile, err)
	}

	return nil
}

func writeFile(path string, content string) (err error) {
	file, err := os.Create(path)
	if err != nil {
		return fmt.Errorf("create %q: %w", path, err)
	}
	defer func() {
		closeErr := file.Close()
		if err == nil && closeErr != nil {
			err = fmt.Errorf("close %q: %w", path, closeErr)
		}
	}()

	if _, err := file.WriteString(content); err != nil {
		return fmt.Errorf("write %q: %w", path, err)
	}
	return nil
}