package game

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

	"thirdcollapse/internal/net"
	"gopkg.in/yaml.v3"
)

type HelpDef struct {
	Name     string `yaml:"name"`
	Category string `yaml:"category"`
	Content  string `yaml:"description"`
}

func LoadHelp(dataDir string) ([]HelpDef, error) {
	dir := filepath.Join(dataDir, "help")
	entries, err := os.ReadDir(dir)
	if err != nil {
		return nil, err
	}

	var helps []HelpDef
	for _, entry := range entries {
		if entry.IsDir() || filepath.Ext(entry.Name()) != ".yaml" {
			continue
		}
		data, err := os.ReadFile(filepath.Join(dir, entry.Name()))
		if err != nil {
			continue
		}
		var h HelpDef
		if err := yaml.Unmarshal(data, &h); err != nil {
			continue
		}
		helps = append(helps, h)
	}
	return helps, nil
}

func (g *Game) doHelp(sess *net.Session, topic string) {
	helps, err := LoadHelp(g.dataDir)
	if err != nil || len(helps) == 0 {
		sess.WriteLine("No help available.")
		return
	}

	if topic == "" {
		// Group by category
		cats := make(map[string][]HelpDef)
		var catOrder []string
		for _, h := range helps {
			if _, ok := cats[h.Category]; !ok {
				catOrder = append(catOrder, h.Category)
			}
			cats[h.Category] = append(cats[h.Category], h)
		}

		sess.WriteLine("\nCommands:")
		for _, cat := range catOrder {
			sess.WriteLine(fmt.Sprintf("\n  %s:", cat))
			for _, h := range cats[cat] {
				sess.WriteLine(fmt.Sprintf("    %-12s - %s", h.Name, firstLine(h.Content)))
			}
		}
		sess.WriteLine("\n  Use 'help <command>' for details.")
		return
	}

	topic = strings.ToLower(topic)
	for _, h := range helps {
		if strings.ToLower(h.Name) == topic {
			sess.WriteLine(fmt.Sprintf("\n  %s", h.Content))
			return
		}
	}
	sess.WriteLine(fmt.Sprintf("No help found for '%s'.", topic))
}

func firstLine(s string) string {
	if idx := strings.Index(s, "\n"); idx >= 0 {
		return s[:idx]
	}
	return s
}