package main

import (
	"bufio"
	"fmt"
	"log"
	"os"
	"sort"
	"strings"
	"sync"
	"time"

	"forgejo.edf-bootstrap.cx.fg1.ffm.osc.live/richardrobertreitz/docudile/lib"
)

type field struct {
	name        string
	enums       string
	kind        string
	required    bool
	description []string
	fields      []field
	uuid        string
}

type spec struct {
	uuid        string
	group       string
	kind        string
	version     string
	field       []string
	description []string
	fields      []field
	enums       string
	specs       []spec
}

type index struct {
	name    string
	version string
	key     string
	uuid    string
	group   string
}

func main() {
	if len(os.Args) != 2 {
		log.Fatal("args: <directory> # output directory for generated files")
	}

	cluster, err := lib.ExecNotFatal(`#!/bin/bash
	kubectl config current-context
	`, []string{})

	if err != nil {
		log.Fatal("error: ", err)
	}
	t := time.Now()
	cluster = ", " + cluster + ", " + t.String()

	outputDir := os.Args[1]
	if !strings.HasSuffix(outputDir, "/") {
		outputDir += "/"
	}

	create(false, "", outputDir, cluster)
	//create(true, "pod", outputDir)
	//create(true, "bashes.provisioning.shell.crossplane.io", outputDir)
	//return

	out, err := lib.ExecNotFatal(`#!/bin/bash
	kubectl api-resources --verbs=list -o name | sort
	`, []string{})

	if err != nil {
		log.Fatal("error: ", err)
	}

	scans := []string{}
	scanner := bufio.NewScanner(strings.NewReader(out))
	for scanner.Scan() {
		scans = append(scans, scanner.Text())
	}

	if err := scanner.Err(); err != nil {
		log.Fatal("error: ", err)
	}

	var wg sync.WaitGroup
	wg.Add(len(scans))

	for _, page := range scans {
		go func(page string) {
			defer wg.Done()
			if !strings.HasPrefix(page, "events.events.k8s.io") && !strings.HasPrefix(page, "nodes.metrics.k8s.io") && !strings.HasPrefix(page, "pods.metrics.k8s.io") {
				create(true, page, outputDir, cluster)
				fmt.Println("scaned " + page)
			} else {
				fmt.Println("warning, skipped " + page)
			}
		}(page)
	}
	wg.Wait()
}

func create(pages bool, page string, dir string, cluster string) {
	specs := make(map[string]spec)
	arg := ""

	if !pages {
		out, err := lib.ExecNotFatal(`#!/bin/bash
	kubectl api-resources --verbs=list -o name | sort
	`, []string{})

		if err != nil {
			log.Fatal("error: ", err)
		}

		scanner := bufio.NewScanner(strings.NewReader(out))
		for scanner.Scan() {
			spec := getSpec(0, scanner.Text())
			if len(spec.uuid) > 0 {
				specs[spec.uuid] = spec
			}
		}

		if err := scanner.Err(); err != nil {
			log.Fatal("error: ", err)
		}
	} else {
		arg = page
		spec := getSpec(1, page)
		specs[spec.uuid] = spec
	}

	tree := []spec{}

	for _, spec := range specs {
		tree = append(tree, spec)
	}

	sort.SliceStable(tree, func(i, j int) bool {
		if tree[i].group == tree[j].group {
			return tree[i].kind < tree[j].kind
		} else {
			groupA := strings.Fields(strings.Replace(tree[i].group, ".", " ", -1))
			revGroupA := strings.Join(reverse(groupA), ".")
			groupB := strings.Fields(strings.Replace(tree[j].group, ".", " ", -1))
			revGroupB := strings.Join(reverse(groupB), ".")
			return revGroupA < revGroupB
		}
	})

	if !pages {
		fmt.Println("create index")
		out := createFile(dir + "index.html")
		outOne := createFile(dir + "onepage.html")
		writeFile(out, "multi page <a href=\"onepage.html\">one page</a>"+cluster)
		writeFile(outOne, "<a href=\"index.html\">multi page</a> one page"+cluster)
		writeFile(out, "<p><h3>Groups</h3>")
		writeFile(outOne, "<p><h3>Groups</h3>")
		last := ""
		for _, object := range tree {
			if len(object.group) == 0 {
				if last != "default" {
					last = "default"
					writeFile(out, last+"<dl><dd>")
					writeFile(outOne, last+"<dl><dd>")
				}
				writeFile(out, "<a href=\"index_"+object.uuid+".html\">"+object.kind+"</a><br>")
				writeFile(outOne, "<a href=\"onepage_"+object.uuid+".html\">"+object.kind+"</a><br>")
			} else {
				group := strings.Fields(strings.Replace(object.group, ".", " ", -1))
				revGroup := strings.Join(reverse(group), ".")
				if last != revGroup {
					last = revGroup
					writeFile(out, "</dd></dl>"+revGroup+"<dl><dd>")
					writeFile(outOne, "</dd></dl>"+revGroup+"<dl><dd>")
				}
				writeFile(out, "<a href=\"index_"+object.uuid+".html\">"+object.kind+"</a><br>")
				writeFile(outOne, "<a href=\"onepage_"+object.uuid+".html\">"+object.kind+"</a><br>")
			}
		}
		writeFile(out, "</dd></dl</p>")
		writeFile(outOne, "</dd></dl</p>")

		objects := []index{}

		for name, spec := range specs {
			objects = append(objects, index{spec.kind, spec.version, name, spec.uuid, spec.group})
		}

		sort.SliceStable(objects, func(i, j int) bool {
			groupA := strings.Fields(strings.Replace(objects[i].group, ".", " ", -1))
			revGroupA := strings.Join(reverse(groupA), ".")
			groupB := strings.Fields(strings.Replace(objects[j].group, ".", " ", -1))
			revGroupB := strings.Join(reverse(groupB), ".")
			if objects[i].name == objects[j].name && revGroupA == revGroupB {
				return objects[i].version < objects[j].version
			} else if objects[i].name == objects[j].name {
				return revGroupA < revGroupB
			} else {
				return objects[i].name < objects[j].name
			}
		})

		writeFile(out, "<p><h3>Index</h3>")
		writeFile(outOne, "<p><h3>Index</h3>")
		for _, object := range objects {
			if len(object.group) == 0 {
				writeFile(out, "<a href=\"index_"+object.uuid+".html\">"+object.name+"</a> default<br>")
				writeFile(outOne, "<a href=\"onepage_"+object.uuid+".html\">"+object.name+"</a> default<br>")
			} else {
				group := strings.Fields(strings.Replace(object.group, ".", " ", -1))
				revGroup := strings.Join(reverse(group), ".")
				writeFile(out, "<a href=\"index_"+object.uuid+".html\">"+object.name+"</a> "+revGroup+"<br>")
				writeFile(outOne, "<a href=\"onepage_"+object.uuid+".html\">"+object.name+"</a> "+revGroup+"<br>")
			}
		}
		writeFile(out, "</p>")
		writeFile(outOne, "</p>")
		closeFile(out)
		closeFile(outOne)
	} else {
		for _, spec := range tree {
			printSpec(spec, true, arg, dir)
		}

		for _, spec := range tree {
			recurseSpecs(spec, arg, dir)
		}
	}
}

func getSpec(level int, specName string) spec {
	spec := spec{}

	if strings.HasPrefix(specName, "customresourcedefinitions.apiextensions.k8s.io.spec.versions.schema.openAPIV3Schema") {
		fmt.Println("warning, skipping " + specName)
		return spec
	}

	out, err := lib.ExecNotFatal(`#!/bin/bash
	kubectl explain "${SPEC}"
	`, []string{"SPEC=" + specName})

	if err != nil {
		if specName == "events.events.k8s.io" || specName == "nodes.metrics.k8s.io" || specName == "pods.metrics.k8s.io" {
			return spec
		} else {
			log.Fatal("cant lookup "+specName+": ", err)
		}
	}

	spec.uuid = specName

	currentField := field{}
	scanner := bufio.NewScanner(strings.NewReader(out))
	step := 0
	scans := []string{}
	for scanner.Scan() {
		scans = append(scans, scanner.Text())
	}
	//fmt.Println("--- " + specName)
	for u := range scans {
		line := scans[u]
		if step == 0 {
			if strings.HasPrefix(line, "GROUP:") {
				word := line[6:]
				spec.group = strings.Join(strings.Fields(word), " ")
			} else if strings.HasPrefix(line, "KIND:") {
				word := line[5:]
				spec.kind = strings.Join(strings.Fields(word), " ")
				step++
			}
			step++
		} else if step == 1 {
			if strings.HasPrefix(line, "KIND:") {
				word := line[5:]
				spec.kind = strings.Join(strings.Fields(word), " ")
				step++
			} else {
				log.Fatal("cant find kind type")
			}
		} else if step == 2 {
			if strings.HasPrefix(line, "VERSION:") {
				word := line[8:]
				spec.version = strings.Join(strings.Fields(word), " ")
				step++
			} else {
				log.Fatal("cant find kind type")
			}
		} else if step == 3 {
			if len(strings.TrimSpace(line)) == 0 {
				step++
			} else {
				log.Fatal("cant find new line 1")
			}
		} else if step == 8 {
			if len(strings.TrimSpace(line)) == 0 {
				step = 4
			} else {
				spec.enums += ", " + strings.TrimSpace(line)
			}
		} else if step == 5 {
			if len(strings.TrimSpace(line)) == 0 {
				step = 3
			} else {
				if strings.TrimSpace(line) == "ENUM:" {
					step = 8
				} else {
					log.Fatal("cant find new line 2 :" + line + ":")
				}
			}
		} else if step == 4 {
			if strings.HasPrefix(line, "FIELD:") {
				word := line[6:]
				spec.field = strings.Fields(word)
				step = 5
			} else if strings.HasPrefix(line, "DESCRIPTION:") {
				step = 6
			} else {
				log.Fatal("cant find field or description type")
			}
		} else if step == 6 {
			if !strings.HasPrefix(line, "FIELDS:") {
				if len(line) != 0 {
					spec.description = append(spec.description, strings.TrimSpace(line))
				}
			} else {
				step++
			}
		} else if step == 7 {
			runes := []rune(line)
			if strings.HasPrefix(strings.TrimSpace(line), "enum:") {
				currentField.enums = line[8:]
			} else if len(runes) > 0 && runes[0] == 32 && runes[1] == 32 && runes[2] != 32 {
				stringSlice := strings.Fields(line)
				if !(len(stringSlice) == 2 || len(stringSlice) == 3) {
					log.Fatal("wrong object type: " + line)
				}
				currentField.name = stringSlice[0]
				currentField.kind = stringSlice[1][1 : len(stringSlice[1])-1]
				if len(stringSlice) == 3 && stringSlice[2] == "-required-" {
					currentField.required = true
				}
			} else {
				currentField.uuid = spec.uuid
				currentField.description = append(currentField.description, strings.TrimSpace(line))
				if len(strings.TrimSpace(line)) == 0 {
					if u >= len(scans)-1 {
						if len(strings.TrimSpace(currentField.name)) == 0 {
							log.Fatal("field requires a name:" + line)
						}
						if level > 0 {
							subSpec := getSpec(level+1, specName+"."+strings.TrimSpace(currentField.name))
							currentField.fields = append(currentField.fields, subSpec.fields...)
							spec.specs = append(spec.specs, subSpec)
						}
						spec.fields = append(spec.fields, currentField)
						currentField = field{}
					} else {
						localRunes := []rune(scans[u+1])
						if len(localRunes) > 0 && localRunes[0] == 32 && localRunes[1] == 32 && localRunes[2] != 32 {
							if len(strings.TrimSpace(currentField.name)) == 0 {
								log.Fatal("field requires a name:" + line)
							}
							if level > 0 {
								subSpec := getSpec(level+1, specName+"."+strings.TrimSpace(currentField.name))
								currentField.fields = append(currentField.fields, subSpec.fields...)
								spec.specs = append(spec.specs, subSpec)
							}
							spec.fields = append(spec.fields, currentField)
							currentField = field{}
						}
					}
				}
			}
		}
	}

	if err := scanner.Err(); err != nil {
		log.Fatal("error: ", err)
	}

	if len(spec.field) != 2 && len(spec.field) != 0 {
		log.Fatal("type field should contain 2 or 0 elements, found " + fmt.Sprint(len(spec.field)))
	}

	if len(spec.description) > 0 {
		if len(strings.TrimSpace(spec.description[len(spec.description)-1])) == 0 {
			spec.description = spec.description[:len(spec.description)-1]
		}
	}

	return spec
}

func recurseSpecs(spec spec, arg string, dir string) {
	printSpec(spec, false, arg, dir)
	for _, subSpec := range spec.specs {
		if len(subSpec.specs) > 0 {
			recurseSpecs(subSpec, arg, dir)
		}
	}
}

func printSpec(spec spec, recurse bool, arg string, dir string) {
	var out *os.File
	if recurse {
		out = createFile(dir + "onepage_" + spec.uuid + ".html")
		writeFile(out, "<a href=\"onepage.html\">index</a><br />")
	} else {
		out = createFile(dir + "index_" + spec.uuid + ".html")
		link := spec.uuid[len(arg):]
		if len(link) > 0 {
			link = link[1:]
		}
		if len(link) > 0 {
			if strings.LastIndex(link, ".") >= 0 {
				link = "." + link[:strings.LastIndex(link, ".")]
			} else {
				link = ""
			}
		}
		if len(arg) != len(spec.uuid) {
			writeFile(out, "<a href=\"index.html\">index</a> <a href=\"index_"+arg+link+".html\">"+strings.ToLower(spec.kind)+link+"</a><br />")
		} else {
			writeFile(out, "<a href=\"index.html\">index</a><br />")
		}
	}
	writeFile(out, "<pre>")
	writeFile(out, "### uuid = "+spec.uuid)
	if len(spec.group) == 0 {
		writeFile(out, "group = 'default'")
	} else {
		writeFile(out, "group = '"+spec.group+"'")
	}
	writeFile(out, "kind = '"+spec.kind+"'")
	writeFile(out, "version = '"+spec.version+"'")
	writeFile(out, "field["+fmt.Sprint(len(spec.field))+"]:")
	for i := 0; i < len(spec.field); i++ {
		writeFile(out, "  "+spec.field[i])
	}
	writeFile(out, "description["+fmt.Sprint(len(spec.description))+"]:")
	for i := 0; i < len(spec.description); i++ {
		writeFile(out, "  "+spec.description[i])
	}
	writeFile(out, "fields["+fmt.Sprint(len(spec.fields))+"]:")
	printFields(1, spec.fields, len(spec.uuid), strings.ToLower(spec.kind), recurse, arg, out)

	writeFile(out, "</pre>")
	closeFile(out)
}

func printFields(level int, fields []field, baseUuidLength int, baseName string, recurse bool, arg string, out *os.File) {
	fill := ""
	for i := 0; i < level; i++ {
		fill += "    "
	}
	for i := range fields {
		linked := ""
		if len(fields[i].fields) > 0 {
			if !recurse {
				linked = ", <a href=\"index_" + fields[i].uuid + "." + fields[i].name + ".html\">link</a>"
			}
		}
		if fields[i].uuid+"."+fields[i].name == "customresourcedefinitions.apiextensions.k8s.io.spec.versions.schema.openAPIV3Schema" {
			writeFile(out, fill+"  "+fields[i].name+", "+fields[i].kind+", "+fmt.Sprint(fields[i].required)+", enums["+fields[i].enums+"]"+linked+" broken")
		} else {
			writeFile(out, fill+"  "+fields[i].name+", "+fields[i].kind+", "+fmt.Sprint(fields[i].required)+", enums["+fields[i].enums+"]"+linked)
		}
		if len(fields[i].uuid) > baseUuidLength && len(fields[i].uuid[baseUuidLength+1:]) > 0 {
			writeFile(out, fill+"  "+baseName+"."+fields[i].uuid[baseUuidLength+1:])
		} else if len(fields[i].uuid) == baseUuidLength {
			if recurse {
				writeFile(out, fill+"  "+baseName)
			} else {
				writeFile(out, fill+"  "+baseName+fields[i].uuid[len(arg):])
			}
		}
		for j := range fields[i].description {
			writeFile(out, fill+"    "+fields[i].description[j])
		}
		if recurse {
			printFields(level+1, fields[i].fields, baseUuidLength, baseName, recurse, arg, out)
		}
	}
}

func reverse(s []string) []string {
	a := make([]string, len(s))
	copy(a, s)

	for i := len(a)/2 - 1; i >= 0; i-- {
		opp := len(a) - 1 - i
		a[i], a[opp] = a[opp], a[i]
	}

	return a
}

func check(e error) {
	if e != nil {
		panic(e)
	}
}

func closeFile(file *os.File) {
	file.Close()
}

func createFile(fileName string) *os.File {
	f, err := os.Create(fileName)
	check(err)
	//fmt.Println("created file " + fileName)
	return f
}

func writeFile(file *os.File, data string) {
	_, err := file.WriteString(data + "\n")
	check(err)
}