package knowledge

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

func LoadSoul(path string) (string, error) {
	b, err := os.ReadFile(path)
	if err != nil {
		return "", fmt.Errorf("read soul file failed: %w", err)
	}
	content := strings.TrimSpace(string(b))
	if content == "" {
		return "", fmt.Errorf("soul file is empty")
	}
	return content, nil
}

func LoadSkills(dir string) (string, error) {
	entries, err := os.ReadDir(dir)
	if err != nil {
		return "", fmt.Errorf("read skills dir failed: %w", err)
	}

	files := make([]string, 0)
	for _, entry := range entries {
		if entry.IsDir() {
			continue
		}
		name := entry.Name()
		if strings.HasSuffix(strings.ToLower(name), ".md") {
			files = append(files, filepath.Join(dir, name))
		}
	}
	sort.Strings(files)

	builder := strings.Builder{}
	for _, file := range files {
		b, err := os.ReadFile(file)
		if err != nil {
			return "", fmt.Errorf("read skill file failed: %w", err)
		}
		content := strings.TrimSpace(string(b))
		if content == "" {
			continue
		}
		builder.WriteString("## ")
		builder.WriteString(filepath.Base(file))
		builder.WriteString("\n")
		builder.WriteString(content)
		builder.WriteString("\n\n")
	}

	out := strings.TrimSpace(builder.String())
	if out == "" {
		return "", fmt.Errorf("no non-empty markdown skills loaded from %s", dir)
	}
	return out, nil
}