package main

import (
	"bufio"
	"context"
	"errors"
	"fmt"
	"iter"
	"math/rand"
	"net/url"
	"os"
	"os/exec"
	"path/filepath"
	"runtime"
	"slices"
	"strconv"
	"strings"
	"sync"
	"time"
	"unicode"

	"fiatjaf.com/nostr"
	"fiatjaf.com/nostr/nip05"
	"fiatjaf.com/nostr/nip19"
	"fiatjaf.com/nostr/schema"
	"fiatjaf.com/nostr/sdk"
	"github.com/chzyer/readline"
	"github.com/fatih/color"
	jsoniter "github.com/json-iterator/go"
	"github.com/lithammer/fuzzysearch/fuzzy"
	"github.com/mattn/go-isatty"
	"github.com/mattn/go-tty/v2"
	"github.com/urfave/cli/v3"
	"golang.org/x/term"
)

var sys *sdk.System

var json = jsoniter.ConfigFastest

const (
	LINE_PROCESSING_ERROR = iota
)

var (
	log        = func(msg string, args ...any) { fmt.Fprintf(color.Error, msg, args...) }
	logverbose = func(msg string, args ...any) {} // by default do nothing
	stdout     = func(args ...any) { fmt.Fprintln(color.Output, args...) }
)

var connectTimeout = 2 * time.Second

func isPiped() bool {
	stat, err := os.Stdin.Stat()
	if err != nil {
		panic(err)
	}

	mode := stat.Mode()
	is := mode&os.ModeCharDevice == 0
	return is
}

func getJsonsOrBlank() iter.Seq[string] {
	var curr strings.Builder

	var finalJsonErr error
	return func(yield func(string) bool) {
		stopped := false
		hasStdin := writeStdinLinesOrNothing(func(stdinLine string) bool {
			// we're look for an event, but it may be in multiple lines, so if json parsing fails
			// we'll try the next line until we're successful
			curr.WriteString(stdinLine)
			stdinEvent := curr.String()

			var dummy any
			if err := json.Unmarshal([]byte(stdinEvent), &dummy); err != nil {
				finalJsonErr = err
				return true
			}
			finalJsonErr = nil

			if !yield(stdinEvent) {
				stopped = true
				return false
			}

			curr.Reset()
			return true
		})

		if stopped {
			return
		}

		if !hasStdin {
			if !yield("{}") {
				return
			}
		}

		if finalJsonErr != nil {
			log(color.YellowString("stdin json parse error: %s", finalJsonErr))
		}
	}
}

func getStdinLinesOrBlank() iter.Seq[string] {
	return func(yield func(string) bool) {
		stopped := false
		hasStdin := writeStdinLinesOrNothing(func(stdinLine string) bool {
			if !yield(stdinLine) {
				stopped = true
				return false
			}
			return true
		})

		if stopped {
			return
		}

		if !hasStdin {
			if !yield("") {
				return
			}
		}
	}
}

func getStdinLinesOrArguments(args cli.Args) iter.Seq[string] {
	return getStdinLinesOrArgumentsFromSlice(args.Slice())
}

func getStdinLinesOrArgumentsFromSlice(args []string) iter.Seq[string] {
	// try the first argument
	if len(args) > 0 {
		return slices.Values(args)
	}

	// try the stdin
	return func(yield func(string) bool) {
		writeStdinLinesOrNothing(yield)
	}
}

func writeStdinLinesOrNothing(yield func(string) bool) (hasStdinLines bool) {
	if isPiped() {
		// piped
		scanner := bufio.NewScanner(os.Stdin)
		scanner.Buffer(make([]byte, 16*1024*1024), 256*1024*1024)
		hasEmittedAtLeastOne := false
		for scanner.Scan() {
			if !yield(strings.TrimSpace(scanner.Text())) {
				return
			}
			hasEmittedAtLeastOne = true
		}
		return hasEmittedAtLeastOne
	} else {
		// not piped
		return false
	}
}

func normalizeAndValidateRelayURLs(wsurls []string) error {
	for i, wsurl := range wsurls {
		wsurl = nostr.NormalizeURL(wsurl)
		wsurls[i] = wsurl

		u, err := url.Parse(wsurl)
		if err != nil {
			return fmt.Errorf("invalid relay url '%s': %s", wsurl, err)
		}

		if u.Scheme != "ws" && u.Scheme != "wss" {
			return fmt.Errorf("relay url must use wss:// or ws:// schemes, got '%s'", wsurl)
		}

		if u.Host == "" {
			return fmt.Errorf("relay url '%s' is missing the hostname", wsurl)
		}
	}

	return nil
}

func connectToAllRelays(
	ctx context.Context,
	c *cli.Command,
	relayUrls []string,
) []*nostr.Relay {
	// first pass to check if these are valid relay URLs
	for i, url := range relayUrls {
		url = nostr.NormalizeURL(url)
		relayUrls[i] = url
		if !nostr.IsValidRelayURL(url) {
			log("invalid relay URL: %s\n", url)
			os.Exit(4)
		}
	}

	relays := make([]*nostr.Relay, 0, len(relayUrls))

	if supportsDynamicMultilineMagic() {
		// overcomplicated multiline rendering magic
		lines := make([][][]byte, len(relayUrls))
		flush := func() {
			for _, line := range lines {
				for _, part := range line {
					os.Stderr.Write(part)
				}
				os.Stderr.Write([]byte{'\n'})
			}
		}
		render := func() {
			clearLines(len(lines))
			flush()
		}
		flush()

		wg := sync.WaitGroup{}
		wg.Add(len(relayUrls))
		mu := sync.Mutex{} // guards lines and relays, written from the goroutines below
		for i, url := range relayUrls {
			lines[i] = make([][]byte, 1, 2)
			logthis := func(s string, args ...any) {
				mu.Lock()
				lines[i] = append(lines[i], []byte(fmt.Sprintf(s, args...)))
				render()
				mu.Unlock()
			}
			colorizepreamble := func(c func(string, ...any) string) {
				mu.Lock()
				lines[i][0] = []byte(fmt.Sprintf("%s... ", c(url)))
				mu.Unlock()
			}
			colorizepreamble(color.CyanString)

			go func() {
				relay := connectToSingleRelay(ctx, c, url, colorizepreamble, logthis)
				if relay != nil {
					mu.Lock()
					relays = append(relays, relay)
					mu.Unlock()
				}
				wg.Done()
			}()
		}
		wg.Wait()
	} else {
		// simple flow
		for _, url := range relayUrls {
			log("connecting to %s... ", color.CyanString(strings.Split(url, "/")[2]))
			relay := connectToSingleRelay(ctx, c, url, nil, log)
			if relay != nil {
				relays = append(relays, relay)
			}
			log("\n")
		}
	}

	return relays
}

func connectToSingleRelay(
	ctx context.Context,
	c *cli.Command,
	url string,
	colorizepreamble func(c func(string, ...any) string),
	logthis func(s string, args ...any),
) *nostr.Relay {
	nm := nostr.NormalizeURL(url)

	relay, ok := sys.Pool.Relays.Load(nm)
	if !ok || relay == nil || !relay.IsConnected() {
		connectCtx, cancel := context.WithTimeout(context.Background(), connectTimeout)
		defer cancel()

		var err error
		if relay, err = nostr.RelayConnect(connectCtx, url, sys.Pool.RelayOptions); err != nil {
			if colorizepreamble != nil {
				colorizepreamble(colors.errorf)
			}
			logthis(clampError(err, len(url)+12))
			return nil
		}

		sys.Pool.Relays.Store(nm, relay)
		go func(r *nostr.Relay, relayURL string) {
			<-r.Context().Done()
			if current, ok := sys.Pool.Relays.Load(relayURL); ok && current == r {
				sys.Pool.Relays.Delete(relayURL)
			}
		}(relay, nm)
	}

	if c.Bool("force-pre-auth") {
		if colorizepreamble != nil {
			colorizepreamble(color.YellowString)
		}
		logthis("waiting for auth challenge... ")
		time.Sleep(time.Millisecond * 200)

		for range 5 {
			if err := relay.Auth(ctx, func(ctx context.Context, authEvent *nostr.Event) error {
				challengeTag := authEvent.Tags.Find("challenge")
				if challengeTag == nil || len(challengeTag) < 2 || challengeTag[1] == "" {
					return fmt.Errorf("auth not received yet *****") // what a giant hack
				}
				return authSigner(ctx, c, logthis, authEvent)
			}); err == nil {
				// auth succeeded
				goto preauthSuccess
			} else {
				// auth failed
				if strings.HasSuffix(err.Error(), "auth not received yet *****") {
					time.Sleep(time.Second)
					continue
				} else {
					if colorizepreamble != nil {
						colorizepreamble(colors.errorf)
					}
					logthis(err.Error())
					return nil
				}
			}
		}
		if colorizepreamble != nil {
			colorizepreamble(colors.errorf)
		}
		logthis("failed to get an AUTH challenge in enough time.")
		return nil
	}

preauthSuccess:
	if colorizepreamble != nil {
		colorizepreamble(colors.successf)
	}
	logthis("ok.")
	return relay
}

func clearLines(lineCount int) {
	for i := 0; i < lineCount; i++ {
		os.Stderr.Write([]byte("\033[0A\033[2K\r"))
	}
}

func supportsDynamicMultilineMagic() bool {
	if runtime.GOOS == "windows" {
		return false
	}
	if !term.IsTerminal(0) {
		return false
	}

	if !isatty.IsTerminal(os.Stdout.Fd()) {
		return false
	}

	width, _, err := term.GetSize(int(os.Stderr.Fd()))
	if err != nil {
		return false
	}
	if width < 110 {
		return false
	}

	return true
}

func lineProcessingError(ctx context.Context, msg string, args ...any) context.Context {
	log(msg+"\n", args...)
	return context.WithValue(ctx, LINE_PROCESSING_ERROR, true)
}

func exitIfLineProcessingError(ctx context.Context) {
	if val := ctx.Value(LINE_PROCESSING_ERROR); val != nil && val.(bool) {
		os.Exit(123)
	}
}

const letterBytes = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ"

func randString(n int) string {
	b := make([]byte, n)
	for i := range b {
		b[i] = letterBytes[rand.Intn(len(letterBytes))]
	}
	return string(b)
}

func unwrapAll(err error) error {
	low := err
	for n := low; n != nil; n = errors.Unwrap(low) {
		low = n
	}
	return low
}

func clampMessage(msg string, prefixAlreadyPrinted int) string {
	termSize, _, _ := term.GetSize(int(os.Stderr.Fd()))

	prf := "expected handshake response status code 101 but got "
	if len(msg) > len(prf) && msg[0:len(prf)] == prf {
		msg = "status " + msg[len(prf):]
	}

	if len(msg) > termSize-prefixAlreadyPrinted && prefixAlreadyPrinted+1 < termSize {
		msg = msg[0:termSize-prefixAlreadyPrinted-1] + "…"
	}

	return msg
}

func clampError(err error, prefixAlreadyPrinted int) string {
	termSize, _, _ := term.GetSize(0)
	msg := err.Error()
	if len(msg) > termSize-prefixAlreadyPrinted {
		err = unwrapAll(err)
		msg = clampMessage(err.Error(), prefixAlreadyPrinted)
	}
	return msg
}

func askConfirmation(msg string) bool {
	if isPiped() {
		tty, err := tty.Open()
		if err != nil {
			return false
		}
		defer tty.Close()

		log(color.YellowString(msg))
		answer, err := tty.ReadString()
		if err != nil {
			return false
		}

		// print newline after password input
		fmt.Fprintln(os.Stderr)

		answer = strings.TrimSpace(string(answer))
		return answer == "y" || answer == "yes"
	} else {
		config := &readline.Config{
			Stdout:                 color.Error,
			Prompt:                 color.YellowString(msg),
			InterruptPrompt:        "^C",
			DisableAutoSaveHistory: true,
			EnableMask:             false,
			MaskRune:               '*',
		}

		rl, err := readline.NewEx(config)
		if err != nil {
			return false
		}

		answer, err := rl.Readline()
		if err != nil {
			return false
		}
		answer = strings.ToLower(strings.TrimSpace(answer))
		return answer == "y" || answer == "yes"
	}
}

func parsePubKey(value string) (nostr.PubKey, error) {
	if nip05.IsValidIdentifier(value) {
		ctx, cancel := context.WithTimeout(context.Background(), time.Second*3)
		pp, err := nip05.QueryIdentifier(ctx, value)
		cancel()
		if err != nil {
			return nostr.ZeroPK, err
		}
		return pp.PublicKey, nil
	}

	pk, err := nostr.PubKeyFromHex(value)
	if err == nil {
		return pk, nil
	}

	if prefix, decoded, err := nip19.Decode(value); err == nil {
		switch prefix {
		case "npub":
			if pk, ok := decoded.(nostr.PubKey); ok {
				return pk, nil
			}
		case "nprofile":
			if profile, ok := decoded.(nostr.ProfilePointer); ok {
				return profile.PublicKey, nil
			}
		}
	}

	return nostr.PubKey{}, fmt.Errorf("invalid pubkey (\"%s\"): expected hex, npub, or nprofile", value)
}

func parseSecretKey(input string) (nostr.SecretKey, error) {
	if prefix, ski, err := nip19.Decode(input); err == nil && prefix == "nsec" {
		return ski.(nostr.SecretKey), nil
	}

	sk, err := nostr.SecretKeyFromHex(input)
	if err != nil {
		return nostr.SecretKey{}, fmt.Errorf("invalid secret key: %w", err)
	}

	return sk, nil
}

func parseEventID(value string) (nostr.ID, error) {
	id, err := nostr.IDFromHex(value)
	if err == nil {
		return id, nil
	}

	if prefix, decoded, err := nip19.Decode(value); err == nil {
		switch prefix {
		case "note":
			if event, ok := decoded.(nostr.EventPointer); ok {
				return event.ID, nil
			}
		case "nevent":
			if event, ok := decoded.(nostr.EventPointer); ok {
				return event.ID, nil
			}
		}
	}

	return nostr.ID{}, fmt.Errorf("invalid event id (\"%s\"): expected hex, note, or nevent", value)
}

func decodeTagValue(value string, letter rune) string {
	letter = unicode.ToLower(letter)

	if letter == 'p' {
		if nip05.IsValidIdentifier(value) {
			ctx, cancel := context.WithTimeout(context.Background(), time.Second*3)
			pp, err := nip05.QueryIdentifier(ctx, value)
			cancel()
			if err == nil {
				return pp.PublicKey.Hex()
			}
		}
	}

	if (letter == 'p' && (strings.HasPrefix(value, "npub1") || strings.HasPrefix(value, "nprofile1"))) ||
		((letter == 'a' || letter == 'q') && strings.HasPrefix(value, "naddr1")) ||
		((letter == 'e' || letter == 'q') && (strings.HasPrefix(value, "nevent1") || strings.HasPrefix(value, "note1"))) {
		if ptr, err := nip19.ToPointer(value); err == nil {
			return ptr.AsTagReference()
		}
	}
	return value
}

func editWithDefaultEditor(filename string, initialContent string, wipe bool) (string, error) {
	fullpath := filepath.Join(os.TempDir(), filename)

	if err := os.MkdirAll(filepath.Dir(fullpath), 0700); err != nil {
		return "", fmt.Errorf("failed to create temp directory: %w", err)
	}

	if wipe {
		if err := os.Remove(fullpath); err != nil && !errors.Is(err, os.ErrNotExist) {
			return "", fmt.Errorf("failed to remove temp file: %w", err)
		}
	}

	tmp, err := os.OpenFile(fullpath, os.O_RDWR|os.O_CREATE|os.O_EXCL, 0600)
	if err != nil {
		return "", fmt.Errorf("failed to create temp file: %w", err)
	}

	if _, err := tmp.WriteString(initialContent); err != nil {
		tmp.Close()
		return "", fmt.Errorf("failed to write temp file: %w", err)
	}
	if err := tmp.Close(); err != nil {
		return "", fmt.Errorf("failed to close temp file: %w", err)
	}

	editor := strings.TrimSpace(os.Getenv("VISUAL"))
	if editor == "" {
		editor = strings.TrimSpace(os.Getenv("EDITOR"))
	}
	if editor == "" {
		editor = "edit"
	}

	parts := strings.Fields(editor)
	if len(parts) == 0 {
		return "", fmt.Errorf("failed to parse editor command '%s'", editor)
	}

	args := append(parts[1:], tmp.Name())
	cmd := exec.Command(parts[0], args...)
	cmd.Stdin = os.Stdin
	cmd.Stdout = os.Stdout
	cmd.Stderr = os.Stderr
	if err := cmd.Run(); err != nil {
		return "", fmt.Errorf("editor command failed: %w", err)
	}

	data, err := os.ReadFile(tmp.Name())
	if err != nil {
		return "", fmt.Errorf("failed to read edited temp file: %w", err)
	}

	return string(data), nil
}

func clampWithEllipsis(s string, size int) string {
	if len(s) <= size {
		return s
	}
	return s[0:size-1] + "…"
}

var (
	schemaURI       string
	fetchSchemaOnce sync.Once
	schemaCache     schema.Schema
	schemaErrCache  error
)

func getSchema() (schema.Schema, error) {
	fetchSchemaOnce.Do(func() {
		if strings.HasPrefix(schemaURI, "http") {
			schemaCache, schemaErrCache = schema.FetchSchemaFromURL(schemaURI)
		} else {
			schemaCache, schemaErrCache = schema.NewSchemaFromFile(schemaURI)
		}
	})
	return schemaCache, schemaErrCache
}

func stringToKind(value string) (nostr.Kind, error) {
	if n, err := strconv.Atoi(value); err == nil && n >= 0 {
		if n > 65535 {
			return 0, fmt.Errorf("kind number %d is out of range (0-65535)", n)
		}
		return nostr.Kind(n), nil
	}

	// find kind from name
	sch, err := getSchema()
	if err != nil {
		return 0, err
	}

	fuzzyWords := make([]string, 0, len(sch.Kinds))
	fuzzyIndexes := make([]string, 0, len(sch.Kinds))

	// exact match
	for k, ks := range sch.Kinds {
		fuzzyWords = append(fuzzyWords, ks.Description)
		fuzzyIndexes = append(fuzzyIndexes, k)

		if strings.EqualFold(ks.Description, value) {
			return ks.Kind, nil
		}
	}

	// fuzzy match
	result := fuzzy.RankFindNormalizedFold(value, fuzzyWords)
	bestDesc := "<none>"
	bestDist := "-"

	if len(result) > 0 {
		if bd := result[0].Distance; bd < 26 {
			return sch.Kinds[fuzzyIndexes[result[0].OriginalIndex]].Kind, nil
		} else {
			bestDesc = sch.Kinds[fuzzyIndexes[result[0].OriginalIndex]].Description
			bestDist = strconv.Itoa(bd)
		}
	}

	return 0, fmt.Errorf("unknown kind: %q (closest: %q, distance: %s)", value, bestDesc, bestDist)
}

var colors = struct {
	reset      func(...any) (int, error)
	italic     func(...any) string
	italicf    func(string, ...any) string
	bold       func(...any) string
	boldf      func(string, ...any) string
	underline  func(...any) string
	underlinef func(string, ...any) string
	error      func(...any) string
	errorf     func(string, ...any) string
	success    func(...any) string
	successf   func(string, ...any) string
}{
	color.New(color.Reset).Print,
	color.New(color.Italic).Sprint,
	color.New(color.Italic).Sprintf,
	color.New(color.Bold).Sprint,
	color.New(color.Bold).Sprintf,
	color.New(color.Underline).Sprint,
	color.New(color.Underline).Sprintf,
	color.New(color.Bold, color.FgHiRed).Sprint,
	color.New(color.Bold, color.FgHiRed).Sprintf,
	color.New(color.Bold, color.FgHiGreen).Sprint,
	color.New(color.Bold, color.FgHiGreen).Sprintf,
}

func combineFlags(flagSlices [][]cli.Flag, extraFlags ...cli.Flag) []cli.Flag {
	total := 0
	for _, s := range flagSlices {
		total += len(s)
	}
	total += len(extraFlags)
	result := make([]cli.Flag, 0, total)
	for _, s := range flagSlices {
		result = append(result, s...)
	}
	result = append(result, extraFlags...)
	return result
}