// Package catalog selects the maintained configuration assets supplied with
// PromptKit. ConfigKit owns their composition and effective validation.
package catalog

import (
	"context"
	"fmt"
	"io/fs"

	"gitea.maximumdirect.net/eric/ConfigKit"
	openrouter "gitea.maximumdirect.net/eric/promptkit-backend-openrouter/v3"
	rakestrawhome "gitea.maximumdirect.net/eric/promptkit-backend-rakestrawhome/v3"
	"gitea.maximumdirect.net/eric/promptkit/internal/backend"
	"gitea.maximumdirect.net/eric/promptkit/internal/filecatalog"
)

// Underlays selects external catalogs followed by PromptKit-owned profiles.
// Neither group is interpreted before the final effective configuration loads.
func Underlays() ([]configkit.Underlay, error) {
	openrouterInputs, err := assetInputs("OpenRouter catalog", openrouter.FS(), openrouter.Root)
	if err != nil {
		return nil, err
	}
	rakestrawhomeInputs, err := assetInputs("Rakestrawhome catalog", rakestrawhome.FS(), rakestrawhome.Root)
	if err != nil {
		return nil, err
	}
	catalogInputs := append(openrouterInputs, rakestrawhomeInputs...)
	openrouterSmokeTestInputs, err := assetInputs("OpenRouter smoke-test catalog", openrouter.FS(), openrouter.SmokeTestsRoot)
	if err != nil {
		return nil, err
	}
	rakestrawhomeSmokeTestInputs, err := assetInputs("Rakestrawhome smoke-test catalog", rakestrawhome.FS(), rakestrawhome.SmokeTestsRoot)
	if err != nil {
		return nil, err
	}
	catalogInputs = append(catalogInputs, openrouterSmokeTestInputs...)
	catalogInputs = append(catalogInputs, rakestrawhomeSmokeTestInputs...)
	owned := configkit.Input{Source: configkit.Mapping("PromptKit-owned profiles", map[string]any{
		"profiles": map[string]any{
			"promptkit-openrouter-standard": map[string]any{"extends": "gemini-flash-latest"},
			"promptkit-openrouter-auto":     map[string]any{"backend": backend.OpenRouterID, "model": "openrouter/auto"},
		},
	})}
	return []configkit.Underlay{{Inputs: catalogInputs}, {Inputs: []configkit.Input{owned}}}, nil
}

func assetInputs(label string, filesystem fs.FS, root string) ([]configkit.Input, error) {
	files, err := filecatalog.FindFSYAMLFiles(context.Background(), filesystem, root)
	if err != nil {
		return nil, fmt.Errorf("discover %s configuration: %w", label, err)
	}
	namespace := configkit.NewFilesystem(label, filesystem)
	inputs := make([]configkit.Input, 0, len(files))
	for _, name := range files {
		inputs = append(inputs, configkit.Input{
			Source:     namespace.File(name),
			Filesystem: &configkit.FilesystemContext{FS: &namespace, Root: root},
		})
	}
	return inputs, nil
}