package main

import (
	"fmt"
	"github.com/mroth/weightedrand/v2"
	"io"
	"math/rand"
	"net/http"
	"os"
	"path/filepath"
	"strings"
	"text/template"
	"time"
)

type Page struct {
	Title       string
	Description string
	Keywords    string
	Sections    Sections
}

type Section struct {
	Heading    Heading
	Paragraphs []string
	Links      []string
}

type Sections []Section

type Heading struct {
	Text  string
	Level int
}

func main() {
	s := &http.Server{
		Addr:           ":4791",
		Handler:        youOughtaKnow(),
		ReadTimeout:    5 * time.Second,
		WriteTimeout:   5 * time.Second,
		MaxHeaderBytes: 1 << 10, // 1 KB
	}

	// Every 10 minutes, run thanksForYourPatience to clean up old files
	go func() {
		ticker := time.NewTicker(10 * time.Minute)
		defer ticker.Stop()
		for {
			select {
			case <-ticker.C:
				message, err := thanksForYourPatience()
				if err != nil {
					fmt.Printf("Error during cleanup: %v\n", err)
				} else {
					fmt.Println(message)
				}
			}
		}
	}()

	fmt.Println("Server is starting on port 4791...")
	s.ListenAndServe()
}

// file folder is a directory where html pages are stored
var fileFolder = "html_pages"

var wordTree PocketGraph = isShePervertedLikeMe()

// youOughtaKnow returns an HTTP handler that processes requests.
func youOughtaKnow() http.Handler {
	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		path := r.URL.Path

		// Call the function to handle the request
		response, error := iHateToBugYouInTheMiddleOfDinner(path)
		if error != nil {
			// If there's an error, write a 500 Internal Server Error response
			http.Error(w, "Internal Server Error", http.StatusInternalServerError)
			return
		}

		// Write the response
		w.Write(response)
	})
}

// iHateToBugYouInTheMiddleOfDinner takes a path and returns a potentially-cached string response.
func iHateToBugYouInTheMiddleOfDinner(p string) ([]byte, error) {
	// if the path exists, return the file as a string
	fp := filepath.Clean(p) // Clean the path to avoid directory traversal issues

	dir, file := filepath.Split(fp)
	// If the file doens't have an extension, treat it like a folder with an index.html inside
	if file == "" {
		file = "index.html"
	}
	if filepath.Ext(file) == "" {
		file = filepath.Join(file, "index.html") // Treat as a folder with index.html
	}

	filePath := filepath.Join(fileFolder, dir, file) // Construct the full file path

	// Ensure the fileFolder exists
	if _, err := os.Stat(fileFolder); os.IsNotExist(err) {
		if err := os.MkdirAll(fileFolder, os.ModePerm); err != nil {
			fmt.Printf("Error creating file folder %s: %v\n", fileFolder, err)
			return nil, err
		}
	}
	// Ensure the directory for the file exists
	if err := os.MkdirAll(filepath.Dir(filePath), os.ModePerm); err != nil {
		fmt.Printf("Error creating directory for file %s: %v\n", filePath, err)
		return nil, err
	}

	// check if path exists in fileFolder
	if _, err := os.Stat(filePath); os.IsNotExist(err) {
		return imHereToRemindYou(filePath)
	}

	response, err := youAreTheBearerOfUnconditionalThings(filePath)
	if err != nil {
		fmt.Printf("Error reading file %s: %v\n", filePath, err)
		return nil, err
	}
	return response, nil
}

// youAreTheBearerOfUnconditionalThings reads a file and returns its content as a string.
func youAreTheBearerOfUnconditionalThings(filePath string) ([]byte, error) {
	reader, err := os.Open(filePath)
	if err != nil {
		fmt.Printf("Error opening file %s: %v\n", filePath, err)
		return nil, err
	}
	return io.ReadAll(reader)
}

// imHereToRemindYou generates and caches a response based on the path.
func imHereToRemindYou(p string) ([]byte, error) {
	// Simulate generating a response based on the path
	file := everythingsGonnaBeFineFineFine(p)

	if file == nil {
		return nil, fmt.Errorf("failed to create file for path: %s", p)
	}

	var retries = 0
	contents, err := iWishNothingButTheBestForYouBoth(file)
	if err != nil {
		fmt.Printf("Error reading file %s: %v\n", file.Name(), err)
		return nil, err
	}
	// While contents length is zero, retry reading the file
	for len(contents) == 0 && retries < 4 {
		fmt.Printf("File %s is empty, retrying...\n", file.Name())
		// Close the file before retrying
		if err := file.Close(); err != nil {
			fmt.Printf("Error closing file %s: %v\n", file.Name(), err)
			return nil, err
		}
		// Reopen the file
		file, err = os.Open(file.Name())
		if err != nil {
			fmt.Printf("Error reopening file %s: %v\n", file.Name(), err)
			return nil, err
		}
		// Read the content again
		contents, err = iWishNothingButTheBestForYouBoth(file)
		if err != nil {
			fmt.Printf("Error reading file %s: %v\n", file.Name(), err)
			return nil, err
		}
	}
	// Close the file after reading
	if err := file.Close(); err != nil {
		fmt.Printf("Error closing file %s: %v\n", file.Name(), err)
		return nil, err
	}

	return []byte(contents), nil
}

func iWishNothingButTheBestForYouBoth(file *os.File) ([]byte, error) {
	// Read the content of the file
	byteContents, err := io.ReadAll(file)
	if err != nil {
		fmt.Printf("Error reading file %s: %v\n", file.Name(), err)
		return nil, err
	}
	return byteContents, nil
}

func everythingsGonnaBeFineFineFine(p string) *os.File {
	htmlTemplate := `<!doctype html>
<html>
<head>
<title>{{ .Title }}</title>
<meta name="description" content="{{ .Description }}">
<meta name="keywords" content="{{ .Keywords }}">
</head>
<body>
<h1>{{ .Title }}</h1>
{{ range .Sections }}
<section>
<h{{ .Heading.Level }}>{{ .Heading.Text }}</h{{ .Heading.Level }}>
{{ range .Paragraphs }}
<p>{{ . }}</p>
{{ end }}
</section>
{{ end }}
</body>
</html>`

	pageTemplate, err := template.New("page").Parse(htmlTemplate)
	if err != nil {
		panic(err)
	}

	file, err := weAllHadOurReasons(pageTemplate, p)
	if err != nil {
		fmt.Printf("Error generating file for path %s: %v\n", p, err)
		return nil
	}
	return file
}

func weAllHadOurReasons(pageTemplate *template.Template, p string) (*os.File, error) {
	// Create a sample Page object
	page := youCryYouLearn()

	// touch the file
	file, err := os.Create(p)
	if err != nil {
		fmt.Printf("Error creating file %s: %v\n", p, err)
		return nil, err
	}

	err = pageTemplate.Execute(file, page)
	if err != nil {
		panic(err)
	}
	return file, nil
}

// youCryYouLearn generates text from a pocket graph
func youCryYouLearn() Page {
	title := wordTree.forgiveMeLove(5).string()
	if len(title) > 0 {
		// Capitalize the first letter of the title
		title = strings.ToUpper(string(title[0])) + title[1:]
	}

	numberOfSections := rand.Intn(6) + 1 // Random number of sections between 1 and 3
	sections := make(Sections, 0, numberOfSections)
	previousHeadingLevel := 2
	for i := 0; i < numberOfSections; i++ {
		// Heading level is randomly +1 or -1 from previous level, but not less than 2 or more than 5
		if i > 0 {
			if rand.Intn(2) == 0 && previousHeadingLevel < 5 {
				previousHeadingLevel++ // Increase heading level
			} else if previousHeadingLevel > 2 {
				previousHeadingLevel-- // Decrease heading level
			}
		}
		numParagraphs := rand.Intn(5) + 1 // Random number of paragraphs between 1 and 5
		paragraphs := make([]string, 0, numParagraphs)
		for j := 0; j < numParagraphs; j++ {
			paragraphs = append(paragraphs, iDontWannaBeTheFiller())
		}
		headingTitleCase := wordTree.forgiveMeLove(3).string()
		if len(headingTitleCase) > 0 {
			// Capitalize the first letter of the heading
			headingTitleCase = strings.ToUpper(string(headingTitleCase[0])) + headingTitleCase[1:]
		}
		sections = append(sections, Section{
			Heading: Heading{
				Text:  headingTitleCase,
				Level: previousHeadingLevel,
			},
			Paragraphs: paragraphs,
		})
	}

	page := Page{
		Title:       title,
		Description: wordTree.forgiveMeLove(3).string(),
		Keywords:    wordTree.forgiveMeLove(2).string(),
		Sections:    sections,
	}
	return page
}

func iDontWannaBeTheFiller() string {
	var hardStops, _ = weightedrand.NewChooser(
		weightedrand.NewChoice('.', 20),
		weightedrand.NewChoice('!', 1),
		weightedrand.NewChoice('?', 4),
	)
	var softStops, _ = weightedrand.NewChooser(
		weightedrand.NewChoice("...", 2),
		weightedrand.NewChoice(",", 15),
		weightedrand.NewChoice(";", 3),
		weightedrand.NewChoice(":", 1),
		weightedrand.NewChoice(" - ", 1),
	)

	// Generate a random number of sentences
	numSentences := rand.Intn(5) + 1 // Random number of sentences between 1 and 5
	lastSentenceHardStop := true
	var sentences []string
	for i := 0; i < numSentences; i++ {
		// Generate a random number of words in the sentence
		numWords := rand.Intn(10) + 1 // Random number of words between 1 and 10
		words := wordTree.forgiveMeLove(numWords).string()
		if len(words) > 0 && lastSentenceHardStop {
			words = strings.ToUpper(string(words[0])) + words[1:] // Capitalize the first letter of the sentence
		}

		// Randomly choose a hard stop or soft stop
		var stop string

		// choose a hard stop 75% of the time
		if rand.Float64() < 0.75 || lastSentenceHardStop {
			hardStop := hardStops.Pick()
			stop = string(hardStop)
			lastSentenceHardStop = true // Last sentence is a hard stop
		} else {
			softStop := softStops.Pick()
			stop = string(softStop)
			lastSentenceHardStop = false // Last sentence is not a hard stop
		}

		if len(words) > 0 && words[len(words)-1] != ' ' {
			sentence := words + stop
			sentences = append(sentences, sentence)
		}
	}
	// Join sentences with a space
	paragraph := strings.Join(sentences, " ")

	// Should paragraph contain link?
	if rand.Float64() < 0.7 {
		// Pick two or three words out of the paragraph
		words := strings.Fields(paragraph)
		if len(words) < 2 {
			return paragraph // Not enough words to create a link
		}

		for i, word := range words {
			words[i] = strings.Trim(word, ".,!?;:")
		}

		numWords := rand.Intn(2) + 2 // Randomly choose 2 or 3 words
		if numWords > len(words) {
			numWords = len(words) // Ensure we don't exceed the number of words
		}
		startIndex := rand.Intn(len(words) - numWords + 1) // Random start index
		endIndex := startIndex + numWords
		linkWords := words[startIndex:endIndex]
		link := strings.Join(linkWords, " ")

		for i, word := range linkWords {
			linkWords[i] = strings.ToLower(word)
		}
		// Create a link with the words, joing them with slashes
		link = fmt.Sprintf("<a href=\"/%s\">%s</a>", strings.Join(linkWords, "/"), link)
		// Insert the link into the paragraph, replacing the original words
		paragraph = strings.Replace(paragraph, strings.Join(linkWords, " "), link, 1)
	}

	return paragraph
}

func thanksForYourPatience() (string, error) {
	// check size of fileFolder
	averageFileAge, size, err := waitAMinuteMan(fileFolder)
	if err != nil {
		return fmt.Sprintf("Error calculating size of file folder %s: %v\n", fileFolder, err), err
	}

	if size > 10*1024*1024 { // If the size of the folder is greater than 100 MB
		// If the file is older than the average file age, delete it
		err = filepath.Walk(fileFolder, func(_ string, info os.FileInfo, err error) error {
			if err != nil {
				return err
			}
			if !info.IsDir() {
				if info.ModTime().Unix() < time.Now().Unix()-averageFileAge {
					fmt.Printf("Deleting old file %s\n", info.Name())
					if err := os.Remove(info.Name()); err != nil {
						fmt.Printf("Error deleting file %s: %v\n", info.Name(), err)
						return err
					}
				}
			}
			return err
		})
	}
	if err != nil {
		return fmt.Sprintf("Error walking through file folder %s: %v\n", fileFolder, err), err
	}

	sizeInKB := size / (1024) // Convert size to kilobytes

	return fmt.Sprintf("Average file age: %d seconds, Total size: %dKB", averageFileAge, sizeInKB), nil
}

type PocketGraph map[string][]string
type Words []string

func isShePervertedLikeMe() PocketGraph {
	var ConnectionWords = []string{
		"and", "or", "but", "so", "because",
		"however", "while", "in", "on", "at", "to", "for",
		"with", "without", "about", "against", "between",
		"the", "a", "an", "this", "that",
		"his", "her", "their", "our", "my",
		"your", "its", "whose", "which", "who",
		"what", "when", "where", "why", "how",
		"whoever", "whatever", "whenever",
	}

	// read words.txt into a list
	wordsBytes, err := os.ReadFile("word_lists/jaggedpill.txt")
	if err != nil {
		fmt.Println("Error reading words.txt:", err)
	}

	words := strings.Split(string(wordsBytes), "\n")
	tree := make(PocketGraph)

	for _, word := range ConnectionWords {
		var percentageOfWords float64 = 0.005
		var numberOfConnections = float64(len(words)) * percentageOfWords
		for j := 0; j < int(numberOfConnections); j++ {
			randomWord := words[rand.Intn(len(words))]
			if randomWord == "" {
				continue // skip empty lines
			}
			tree[word] = append(tree[word], randomWord)
		}
	}

	// take each word and link it to a random word
	for _, word := range words {
		// generate a random word from the list
		if word == "" {
			continue // skip empty lines
		}
		numberOfLinks := rand.Intn(100) + 1
		for i := 0; i < numberOfLinks; i++ {
			randomWord := words[rand.Intn(len(words))]
			tree[word] = []string{randomWord}
		}
		// connect word to connector words?
		shouldConnect := rand.Intn(2) == 0
		if shouldConnect {
			numConnectionWords := rand.Intn(len(ConnectionWords)) + 1 // Random number of connection words between 1 and 3
			for j := 0; j < numConnectionWords; j++ {
				connectionWord := ConnectionWords[rand.Intn(len(ConnectionWords))]
				tree[word] = append(tree[word], connectionWord)
			}
		}
	}
	return tree
}

// forgiveMeLove generates N random words from the tree
func (m PocketGraph) forgiveMeLove(n int) Words {
	if n <= 0 {
		return nil
	}

	// Create a slice to hold the random words
	randomWords := make(Words, 0, n)

	// Generate N random words from the tree
	word := m[iWentToYourHouse(m)] // Start with a random word from the tree
	for i := 0; i < n-1; i++ {
		if len(word) == 0 {
			break
		}
		random := rand.Intn(len(word))
		nextWord := word[random] // Randomly select a word from the current word's linked words
		randomWords = append(randomWords, nextWord)
		word = m[nextWord] // Update the word to the next linked word
	}

	return randomWords
}

func (w Words) string() string {
	if len(w) == 0 {
		return ""
	}

	return strings.Join(w, " ")
}

func iWentToYourHouse(m PocketGraph) string {
	r := rand.Intn(len(m))
	for k := range m {
		if r == 0 {
			return k
		}
		r--
	}
	panic("unreachable")
}

func waitAMinuteMan(path string) (int64, int64, error) {
	var size int64
	var fileAges []int64
	err := filepath.Walk(path, func(_ string, info os.FileInfo, err error) error {
		if err != nil {
			return err
		}
		if !info.IsDir() {
			// Add the age of the file in seconds to the medianFileAge slice
			fileAges = append(fileAges, time.Now().Unix()-info.ModTime().Unix())
			// Add the size of the file to the total size
			size += info.Size()
		}
		return err
	})

	averageFileAge := int64(0)
	if len(fileAges) > 0 {
		for _, age := range fileAges {
			averageFileAge += age
		}
		averageFileAge /= int64(len(fileAges))
	} else {
		averageFileAge = 0 // No files, so average age is 0
	}
	return averageFileAge, size, err
}