package autotest

import (
	"fmt"
	"os"
	"path/filepath"
	"strings"
)

const (
	ConfigDir   = "testdata/configs"
	ScenarioDir = "testdata/scenarios"
)

func ResolveConfigPath(name string) (string, error) {
	return resolveJSON(name, ConfigDir)
}

func ResolveScenarioPath(name string) (string, error) {
	return resolveJSON(name, ScenarioDir)
}

func resolveJSON(name, dir string) (string, error) {
	if name == "" {
		return "", fmt.Errorf("empty name")
	}
	if filepath.Ext(name) == ".json" {
		if fileExists(name) {
			return name, nil
		}
	}
	base := name
	if filepath.Ext(base) != ".json" {
		base += ".json"
	}
	for _, root := range configRoots() {
		p := filepath.Join(root, dir, base)
		if fileExists(p) {
			return p, nil
		}
	}
	return "", fmt.Errorf("not found: %s (searched %s under gotool)", base, dir)
}

func configRoots() []string {
	var roots []string
	if wd, err := os.Getwd(); err == nil {
		roots = append(roots, wd)
	}
	// When run from repo root via make.
	roots = append(roots, "goTool", filepath.Join("..", "goTool"))
	return roots
}

func fileExists(path string) bool {
	st, err := os.Stat(path)
	return err == nil && !st.IsDir()
}

func ListJSONFiles(dir string) ([]string, error) {
	for _, root := range configRoots() {
		p := filepath.Join(root, dir)
		entries, err := os.ReadDir(p)
		if err != nil {
			continue
		}
		var names []string
		for _, e := range entries {
			if e.IsDir() || filepath.Ext(e.Name()) != ".json" {
				continue
			}
			names = append(names, strings.TrimSuffix(e.Name(), ".json"))
		}
		if len(names) > 0 {
			return names, nil
		}
	}
	return nil, fmt.Errorf("directory %s not found", dir)
}