package main

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

	"github.com/mailru/easyjson"
	"github.com/nbd-wtf/go-nostr"
	"github.com/nbd-wtf/go-nostr/nson"
	"github.com/urfave/cli/v2"
)

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",
			DefaultText: "the key '1'",
			Value:       "0000000000000000000000000000000000000000000000000000000000000001",
		},
		&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 {
		evt := nostr.Event{
			Tags: make(nostr.Tags, 0, 3),
		}

		mustRehashAndResign := false

		if stdinEvent := getStdin(); stdinEvent != "" {
			if err := json.Unmarshal([]byte(stdinEvent), &evt); err != nil {
				return fmt.Errorf("invalid event received from stdin: %w", err)
			}
		}

		if kind := c.Int("kind"); kind != 0 {
			evt.Kind = kind
			mustRehashAndResign = true
		} else if evt.Kind == 0 {
			evt.Kind = 1
			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(c.String("sec")); err != nil {
				return fmt.Errorf("error signing with provided key: %w", err)
			}
		}

		relays := c.Args().Slice()
		if len(relays) > 0 {
			fmt.Println(evt.String())
			for _, url := range relays {
				fmt.Fprintf(os.Stderr, "publishing to %s... ", url)
				if relay, err := nostr.RelayConnect(c.Context, url); err != nil {
					fmt.Fprintf(os.Stderr, "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 {
						fmt.Fprintf(os.Stderr, "failed: %s\n", err)
					} else {
						fmt.Fprintf(os.Stderr, "%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)
		}

		return nil
	},
}