package main

import (
	"context"
	"encoding/json"
	"fmt"
	"os"
	"strconv"
	"strings"
	"time"

	"github.com/bgentry/speakeasy"
	"github.com/mailru/easyjson"
	"github.com/nbd-wtf/go-nostr"
	"github.com/nbd-wtf/go-nostr/nip19"
	"github.com/nbd-wtf/go-nostr/nson"
	"github.com/urfave/cli/v2"
	"golang.org/x/exp/slices"
)

const CATEGORY_EVENT_FIELDS = "EVENT FIELDS"

var event = &cli.Command{
	Name:  "event",
	Usage: "generates an encoded event and either prints it or sends it to a set of relays",
	Description: `outputs an event built with the flags. if one or more relays are given as arguments, an attempt is also made to publish the event to these relays.

example:
		nak event -c hello wss://nos.lol
		nak event -k 3 -p 3bf0c63fcb93463407af97a5e5ee64fa883d107ef9e558472c4eb9aaaefa459d

if an event -- or a partial event -- is given on stdin, the flags can be used to optionally modify it. if it is modified it is rehashed and resigned, otherwise it is just returned as given, but that can be used to just publish to relays.

example:
		echo '{"id":"a889df6a387419ff204305f4c2d296ee328c3cd4f8b62f205648a541b4554dfb","pubkey":"c6047f9441ed7d6d3045406e95c07cd85c778e4b8cef3ca7abac09b95c709ee5","created_at":1698623783,"kind":1,"tags":[],"content":"hello from the nostr army knife","sig":"84876e1ee3e726da84e5d195eb79358b2b3eaa4d9bd38456fde3e8a2af3f1cd4cda23f23fda454869975b3688797d4c66e12f4c51c1b43c6d2997c5e61865661"}' | nak event wss://offchain.pub
		echo '{"tags": [["t", "spam"]]}' | nak event -c 'this is spam'
`,
	Flags: []cli.Flag{
		&cli.StringFlag{
			Name:        "sec",
			Usage:       "secret key to sign the event, as hex or nsec",
			DefaultText: "the key '1'",
			Value:       "0000000000000000000000000000000000000000000000000000000000000001",
		},
		&cli.BoolFlag{
			Name:  "prompt-sec",
			Usage: "prompt the user to paste a hex or nsec with which to sign the event",
		},
		&cli.BoolFlag{
			Name:  "envelope",
			Usage: "print the event enveloped in a [\"EVENT\", ...] message ready to be sent to a relay",
		},
		&cli.BoolFlag{
			Name:  "nson",
			Usage: "encode the event using NSON",
		},
		&cli.IntFlag{
			Name:        "kind",
			Aliases:     []string{"k"},
			Usage:       "event kind",
			DefaultText: "1",
			Value:       0,
			Category:    CATEGORY_EVENT_FIELDS,
		},
		&cli.StringFlag{
			Name:        "content",
			Aliases:     []string{"c"},
			Usage:       "event content",
			DefaultText: "hello from the nostr army knife",
			Value:       "",
			Category:    CATEGORY_EVENT_FIELDS,
		},
		&cli.StringSliceFlag{
			Name:     "tag",
			Aliases:  []string{"t"},
			Usage:    "sets a tag field on the event, takes a value like -t e=<id>",
			Category: CATEGORY_EVENT_FIELDS,
		},
		&cli.StringSliceFlag{
			Name:     "e",
			Usage:    "shortcut for --tag e=<value>",
			Category: CATEGORY_EVENT_FIELDS,
		},
		&cli.StringSliceFlag{
			Name:     "p",
			Usage:    "shortcut for --tag p=<value>",
			Category: CATEGORY_EVENT_FIELDS,
		},
		&cli.StringFlag{
			Name:        "created-at",
			Aliases:     []string{"time", "ts"},
			Usage:       "unix timestamp value for the created_at field",
			DefaultText: "now",
			Value:       "",
			Category:    CATEGORY_EVENT_FIELDS,
		},
	},
	ArgsUsage: "[relay...]",
	Action: func(c *cli.Context) error {
		// try to connect to the relays here
		var relays []*nostr.Relay
		if relayUrls := c.Args().Slice(); len(relayUrls) > 0 {
			_, relays = connectToAllRelays(c.Context, relayUrls)
			if len(relays) == 0 {
				log("failed to connect to any of the given relays.\n")
				os.Exit(3)
			}
		}

		// gather the secret key first
		sec := c.String("sec")
		if c.Bool("prompt-sec") {
			if isPiped() {
				return fmt.Errorf("can't prompt for a secret key when processing data from a pipe, try again without --prompt-sec")
			}
			var err error
			sec, err = speakeasy.FAsk(os.Stderr, "type your secret key as nsec or hex: ")
			if err != nil {
				return fmt.Errorf("failed to get secret key: %w", err)
			}
		}
		if strings.HasPrefix(sec, "nsec1") {
			_, hex, err := nip19.Decode(sec)
			if err != nil {
				return fmt.Errorf("invalid nsec: %w", err)
			}
			sec = hex.(string)
		}
		if len(sec) > 64 {
			return fmt.Errorf("invalid secret key: too large")
		}
		sec = strings.Repeat("0", 64-len(sec)) + sec // left-pad
		if err := validate32BytesHex(sec); err != nil {
			return fmt.Errorf("invalid secret key")
		}

		// then process input and generate events
		for stdinEvent := range getStdinLinesOrBlank() {
			evt := nostr.Event{
				Tags: make(nostr.Tags, 0, 3),
			}

			kindWasSupplied := true
			mustRehashAndResign := false
			if stdinEvent != "" {
				if err := json.Unmarshal([]byte(stdinEvent), &evt); err != nil {
					lineProcessingError(c, "invalid event received from stdin: %s", err)
					continue
				}
				kindWasSupplied = strings.Contains(stdinEvent, `"kind"`)
			}
			kindWasSupplied = slices.Contains(c.FlagNames(), "kind")

			if kind := c.Int("kind"); kindWasSupplied {
				evt.Kind = kind
				mustRehashAndResign = true
			}

			if content := c.String("content"); content != "" {
				evt.Content = content
				mustRehashAndResign = true
			} else if evt.Content == "" && evt.Kind == 1 {
				evt.Content = "hello from the nostr army knife"
				mustRehashAndResign = true
			}

			tags := make(nostr.Tags, 0, 5)
			for _, tagFlag := range c.StringSlice("tag") {
				// tags are in the format key=value
				spl := strings.Split(tagFlag, "=")
				if len(spl) == 2 && len(spl[0]) > 0 {
					tag := nostr.Tag{spl[0]}
					// tags may also contain extra elements separated with a ";"
					spl2 := strings.Split(spl[1], ";")
					tag = append(tag, spl2...)
					// ~
					tags = append(tags, tag)
				}
			}
			for _, etag := range c.StringSlice("e") {
				tags = append(tags, []string{"e", etag})
				mustRehashAndResign = true
			}
			for _, ptag := range c.StringSlice("p") {
				tags = append(tags, []string{"p", ptag})
				mustRehashAndResign = true
			}
			if len(tags) > 0 {
				for _, tag := range tags {
					evt.Tags = append(evt.Tags, tag)
				}
				mustRehashAndResign = true
			}

			if createdAt := c.String("created-at"); createdAt != "" {
				ts := time.Now()
				if createdAt != "now" {
					if v, err := strconv.ParseInt(createdAt, 10, 64); err != nil {
						return fmt.Errorf("failed to parse timestamp '%s': %w", createdAt, err)
					} else {
						ts = time.Unix(v, 0)
					}
				}
				evt.CreatedAt = nostr.Timestamp(ts.Unix())
				mustRehashAndResign = true
			} else if evt.CreatedAt == 0 {
				evt.CreatedAt = nostr.Now()
				mustRehashAndResign = true
			}

			if evt.Sig == "" || mustRehashAndResign {
				if err := evt.Sign(sec); err != nil {
					return fmt.Errorf("error signing with provided key: %w", err)
				}
			}

			if len(relays) > 0 {
				fmt.Println(evt.String())
				os.Stdout.Sync()
				for _, relay := range relays {
					log("publishing to %s... ", relay.URL)
					if relay, err := nostr.RelayConnect(c.Context, relay.URL); err != nil {
						log("failed to connect: %s\n", err)
					} else {
						ctx, cancel := context.WithTimeout(c.Context, 10*time.Second)
						defer cancel()
						if status, err := relay.Publish(ctx, evt); err != nil {
							log("failed: %s\n", err)
						} else {
							log("%s.\n", status)
						}
					}
				}
			} else {
				var result string
				if c.Bool("envelope") {
					j, _ := json.Marshal([]any{"EVENT", evt})
					result = string(j)
				} else if c.Bool("nson") {
					result, _ = nson.Marshal(&evt)
				} else {
					j, _ := easyjson.Marshal(&evt)
					result = string(j)
				}
				fmt.Println(result)
			}
		}

		exitIfLineProcessingError(c)
		return nil
	},
}