package main

import (
	"encoding/json"
	"flag"
	"fmt"
	"io"
	"net/http"
	"os"
	"os/exec"
	"path/filepath"
	"regexp"
	"strings"
)

type Choice struct {
	TargetID string `json:"targetId"`
	Text     string `json:"text"`
}

type StoryNode struct {
	ID         string            `json:"id"`
	Title      string            `json:"title"`
	Content    string            `json:"content"`
	Choices    []Choice          `json:"choices"`
	IsReboot   bool              `json:"isReboot"`
	IsEnd      bool              `json:"isEnd"`
	FileSource string            `json:"fileSource"`
	Metadata   map[string]string `json:"metadata"`
}

type StoryGraph struct {
	Nodes        map[string]*StoryNode `json:"nodes"`
	StartNodeID  string                `json:"startNodeId"`
	BrokenLinks  []string              `json:"brokenLinks"`
	OrphanNodes  []string              `json:"orphanNodes"`
	DeadEndNodes []string              `json:"deadEndNodes"`
}

var (
	adocNodeRegex   = regexp.MustCompile(`\[\[([a-zA-Z0-9_\-]+)\]\]`)
	adocChoiceRegex = regexp.MustCompile(`<<([a-zA-Z0-9_\-]+)\s*,\s*([^>]+)>>`)
	mdChoiceRegex   = regexp.MustCompile(`\[([^\]]+)\]\((?:#)?([a-zA-Z0-9_\-]+)\)`)
	headingRegex    = regexp.MustCompile(`^(?:={1,4}|#{1,4})\s+(.+)`)
	metaRegex       = regexp.MustCompile(`(?i)\[meta:\s*([a-zA-Z0-9_]+)\s*=\s*([^\]]+)\]`)
)

func main() {
	dirPtr := flag.String("dir", "./stories", "Verzeichnis mit AsciiDoc/Markdown Dateien")
	frontendPtr := flag.String("frontend", "./frontend", "Pfad zum Verzeichnis der statischen Frontend-Dateien")
	outPtr := flag.String("out", "export", "Ziel-Ordner für den Dateiexport (SSG Modus)")
	servePtr := flag.Bool("serve", false, "Startet den Live-Preview-Server (API Modus)")
	portPtr := flag.Int("port", 3344, "Port für den Server")
	flag.Parse()

	fmt.Println("\033[1;36m=== Computer Historyz :: CYOA SSG & API ===\033[0m")

	if info, err := os.Stat(*frontendPtr); os.IsNotExist(err) || !info.IsDir() {
		fmt.Printf("\033[1;33m[WARNUNG]\033[0m Frontend-Verzeichnis '%s' nicht gefunden!\n", *frontendPtr)
	}

	if *servePtr {
		startServer(*portPtr, *dirPtr, *frontendPtr)
		return
	}

	// --- EXPORT MODUS (Static Site Generation) ---
	fmt.Printf("\033[1;34m[EXPORT]\033[0m Kompiliere Story-Graph via Asciidoctor...\n")
	graph := loadStoryGraphFromDir(*dirPtr)
	validateGraph(graph)

	// Export Ordner anlegen
	os.MkdirAll(*outPtr, 0755)

	// 1. Statische Daten als JSON schreiben
	graphPath := filepath.Join(*outPtr, "graph.json")
	graphJson, _ := json.MarshalIndent(graph, "", "  ")
	os.WriteFile(graphPath, graphJson, 0644)

	// 2. Frontend-Dateien 1:1 kopieren
	copyFile(filepath.Join(*frontendPtr, "index.html"), filepath.Join(*outPtr, "index.html"))
	copyFile(filepath.Join(*frontendPtr, "style.css"), filepath.Join(*outPtr, "style.css"))
	copyFile(filepath.Join(*frontendPtr, "engine_logic.js"), filepath.Join(*outPtr, "engine_logic.js"))
	copyFile(filepath.Join(*frontendPtr, "engine_ui.js"), filepath.Join(*outPtr, "engine_ui.js"))

	fmt.Printf("\033[1;32m[ERFOLG]\033[0m Web-App erfolgreich exportiert nach -> \033[1;33m%s/\033[0m\n", *outPtr)
}

func copyFile(src, dst string) {
	input, err := os.ReadFile(src)
	if err != nil {
		fmt.Printf("\033[1;33m[WARNUNG]\033[0m Frontend-Datei %s fehlt.\n", src)
		return
	}
	os.WriteFile(dst, input, 0644)
}

func startServer(port int, watchDir string, frontendDir string) {
	addr := fmt.Sprintf(":%d", port)
	fmt.Printf("\n\033[1;32m[SERVER LÄUFT]\033[0m http://localhost:%d\n", port)

	// Dynamischer API-Endpunkt für graph.json
	http.HandleFunc("/graph.json", func(w http.ResponseWriter, r *http.Request) {
		w.Header().Set("Access-Control-Allow-Origin", "*")
		w.Header().Set("Content-Type", "application/json")

		var graph *StoryGraph
		if r.Method == http.MethodPost {
			bodyBytes, _ := io.ReadAll(r.Body)
			graph = &StoryGraph{Nodes: make(map[string]*StoryNode)}
			parseContent(string(bodyBytes), "API_POST_Stream", graph)
		} else {
			graph = loadStoryGraphFromDir(watchDir)
		}
		validateGraph(graph)
		json.NewEncoder(w).Encode(graph)
	})

	// Liefert alles andere aus dem /frontend Ordner
	fs := http.FileServer(http.Dir(frontendDir))
	http.Handle("/", fs)

	if err := http.ListenAndServe(addr, nil); err != nil {
		fmt.Printf("\033[1;31m[FEHLER]\033[0m %v\n", err)
	}
}

// renderAsciidoctor piped rohen AsciiDoc Text in den lokalen Container-Prozess
func renderAsciidoctor(text string) string {
	if strings.TrimSpace(text) == "" {
		return ""
	}
	cmd := exec.Command("asciidoctor", "--embedded", "-")
	cmd.Stdin = strings.NewReader(text)
	out, err := cmd.Output()
	if err != nil {
		fmt.Printf("\033[1;33m[WARNUNG]\033[0m Asciidoctor Rendering fehlgeschlagen: %v\n", err)
		return strings.ReplaceAll(text, "\n", "<br>")
	}
	return string(out)
}

func cleanBodyText(raw string) string {
	cleaned := adocChoiceRegex.ReplaceAllString(raw, "")
	cleaned = mdChoiceRegex.ReplaceAllString(cleaned, "")
	return strings.TrimSpace(cleaned)
}

func parseContent(rawContent string, sourceName string, graph *StoryGraph) {
	lines := strings.Split(rawContent, "\n")
	var currentNode *StoryNode = nil
	var currentBody strings.Builder

	for _, line := range lines {
		if matches := adocNodeRegex.FindStringSubmatch(line); len(matches) > 1 {
			if currentNode != nil {
				currentNode.Content = renderAsciidoctor(cleanBodyText(currentBody.String()))
				graph.Nodes[currentNode.ID] = currentNode
				currentBody.Reset()
			}
			nodeID := matches[1]
			currentNode = &StoryNode{ ID: nodeID, Title: nodeID, Choices: make([]Choice, 0), FileSource: sourceName, Metadata: make(map[string]string) }
			if graph.StartNodeID == "" || nodeID == "start" || nodeID == "node_start" { graph.StartNodeID = nodeID }
			continue
		}

		if currentNode == nil {
			if strings.TrimSpace(line) != "" {
				baseID := "start"
				if sourceName != "API_POST_Stream" { baseID = strings.TrimSuffix(filepath.Base(sourceName), filepath.Ext(sourceName)) }
				currentNode = &StoryNode{ ID: baseID, Title: baseID, Choices: make([]Choice, 0), FileSource: sourceName, Metadata: make(map[string]string) }
				if graph.StartNodeID == "" { graph.StartNodeID = baseID }
			} else { continue }
		}

		if mMatches := metaRegex.FindStringSubmatch(line); len(mMatches) > 2 {
			currentNode.Metadata[strings.ToLower(mMatches[1])] = strings.TrimSpace(mMatches[2])
			continue
		}

		if hMatches := headingRegex.FindStringSubmatch(line); len(hMatches) > 1 && currentNode.Title == currentNode.ID {
			currentNode.Title = strings.TrimSpace(hMatches[1])
		}

		if cMatches := adocChoiceRegex.FindAllStringSubmatch(line, -1); len(cMatches) > 0 {
			for _, match := range cMatches { currentNode.Choices = append(currentNode.Choices, Choice{TargetID: match[1], Text: strings.TrimSpace(match[2])}) }
		}

		if mMatches := mdChoiceRegex.FindAllStringSubmatch(line, -1); len(mMatches) > 0 {
			for _, match := range mMatches { currentNode.Choices = append(currentNode.Choices, Choice{TargetID: match[2], Text: strings.TrimSpace(match[1])}) }
		}

		lowerLine := strings.ToLower(line)
		if strings.Contains(lowerLine, "[reboot]") || strings.Contains(lowerLine, "speicherabbild") { currentNode.IsReboot = true }
		if strings.Contains(lowerLine, "[ende]") || strings.Contains(lowerLine, "[end]") { currentNode.IsEnd = true }

		currentBody.WriteString(line + "\n")
	}

	if currentNode != nil {
		currentNode.Content = renderAsciidoctor(cleanBodyText(currentBody.String()))
		graph.Nodes[currentNode.ID] = currentNode
	}
}

func loadStoryGraphFromDir(rootDir string) *StoryGraph {
	graph := &StoryGraph{Nodes: make(map[string]*StoryNode)}
	filepath.Walk(rootDir, func(path string, info os.FileInfo, err error) error {
		if err != nil || info.IsDir() { return nil }
		ext := strings.ToLower(filepath.Ext(path))
		if ext != ".adoc" && ext != ".md" { return nil }
		contentBytes, err := os.ReadFile(path)
		if err == nil {
			relPath, _ := filepath.Rel(rootDir, path)
			parseContent(string(contentBytes), relPath, graph)
		}
		return nil
	})
	return graph
}

func validateGraph(g *StoryGraph) {
	referenced := make(map[string]bool)
	if g.StartNodeID != "" { referenced[g.StartNodeID] = true }
	for id, node := range g.Nodes {
		for _, choice := range node.Choices {
			referenced[choice.TargetID] = true
			if _, exists := g.Nodes[choice.TargetID]; !exists {
				g.BrokenLinks = append(g.BrokenLinks, fmt.Sprintf("%s -> %s (in %s)", id, choice.TargetID, node.FileSource))
			}
		}
		if len(node.Choices) == 0 && !node.IsReboot && !node.IsEnd {
			g.DeadEndNodes = append(g.DeadEndNodes, id)
		}
	}
	for id := range g.Nodes {
		if !referenced[id] { g.OrphanNodes = append(g.OrphanNodes, id) }
	}
}