package simplex_test

import (
	"errors"
	"slices"
	"strconv"
	"strings"
	"testing"
	"time"

	"sneak.berlin/go/simplexcalc/internal/simplex"
)

// Chat items as simplex-chat v7.0.2 sends them, oldest first: an event it
// records in a chat, the greeting the bot sent, a text, a formatted text
// and a picture a contact sent, and a text the bot sent.
const (
	itemEvent = `{"chatDir":{"type":"directRcv"},"meta":{"itemId":7,
		"itemTs":"2026-09-29T03:13:46.521359978Z",
		"itemText":"Audio/video calls: enabled","itemStatus":{"type":"rcvRead"},
		"createdAt":"2026-09-29T03:13:46.521359978Z"},
		"content":{"type":"rcvChatFeature","feature":"calls",
		"enabled":{"forUser":true,"forContact":true}},"mentions":{},"reactions":[]}`

	itemGreeting = `{"chatDir":{"type":"directSnd"},"meta":{"itemId":8,
		"itemTs":"2026-09-29T03:13:46.925072391Z","itemText":"hi",
		"itemStatus":{"type":"sndRcvd","msgRcptStatus":"ok","sndProgress":"complete"},
		"createdAt":"2026-09-29T03:13:46.925072391Z"},
		"content":{"type":"sndMsgContent","msgContent":{"type":"text","text":"hi"}},
		"mentions":{},"reactions":[]}`

	itemText = `{"chatDir":{"type":"directRcv"},"meta":{"itemId":9,
		"itemTs":"2026-09-29T03:14:34Z","itemText":"2 + 2",
		"itemStatus":{"type":"rcvNew"},"itemSharedMsgId":"bCtLTUFwY3NCSFZIR002Ng==",
		"createdAt":"2026-09-29T03:14:34.865730547Z"},
		"content":{"type":"rcvMsgContent","msgContent":{"type":"text","text":"2 + 2"}},
		"mentions":{},"reactions":[]}`

	itemFormatted = `{"chatDir":{"type":"directRcv"},"meta":{"itemId":10,
		"itemTs":"2026-09-29T03:14:34Z","itemText":"*bold* and _italic_",
		"itemStatus":{"type":"rcvNew"},"createdAt":"2026-09-29T03:14:34.935833284Z"},
		"content":{"type":"rcvMsgContent",
		"msgContent":{"type":"text","text":"*bold* and _italic_"}},"mentions":{},
		"formattedText":[{"format":{"type":"bold"},"text":"bold"},{"text":" and "},
		{"format":{"type":"italic"},"text":"italic"}],"reactions":[]}`

	itemPicture = `{"chatDir":{"type":"directRcv"},"meta":{"itemId":11,
		"itemTs":"2026-09-29T03:14:34Z","itemText":"a picture",
		"itemStatus":{"type":"rcvNew"},"createdAt":"2026-09-29T03:14:35.020538268Z"},
		"content":{"type":"rcvMsgContent","msgContent":{"type":"image",
		"text":"a picture","image":"data:image/jpg;base64,/9j/4AAQSkZJRgABAQ=="}},
		"mentions":{},"reactions":[]}`

	itemSent = `{"chatDir":{"type":"directSnd"},"meta":{"itemId":12,
		"itemTs":"2026-09-29T03:14:43.519552587Z","itemText":"hello from the API",
		"itemStatus":{"type":"sndNew"},"createdAt":"2026-09-29T03:14:43.519552587Z"},
		"content":{"type":"sndMsgContent",
		"msgContent":{"type":"text","text":"hello from the API"}},
		"mentions":{},"reactions":[]}`
)

// The chat client's answer to /_send, and its refusals: of a contact the
// bot does not have, of one who has deleted their chat with the bot, and
// of a text too long for one message.
const (
	sentItems = `{"type":"newChatItems","user":{"userId":1},"chatItems":[
		{"chatInfo":{"type":"direct","contact":{"contactId":3,
		"localDisplayName":"tester","contactStatus":"active"}},
		"chatItem":` + itemSent + `}]}`

	contactNotFound = `{"type":"chatCmdError","chatError":{"type":"errorStore",
		"storeError":{"type":"contactNotFound","contactId":4}}}`

	contactNotReady = `{"type":"chatCmdError","chatError":{"type":"error",
		"errorType":{"type":"contactNotReady","contact":{"contactId":4,
		"localDisplayName":"tester_1","contactStatus":"deleted",
		"activeConn":{"connId":3,"connStatus":{"type":"deleted"}}}}}}`

	largeMsg = `{"type":"chatCmdError","chatError":{"type":"errorStore",
		"storeError":{"type":"largeMsg"}}}`
)

// apiChat is the chat client's answer to /_get chat, holding items.
func apiChat(items ...string) string {
	return `{"type":"apiChat","user":{"userId":1},"chat":{"chatInfo":{
		"type":"direct","contact":{"contactId":3,"localDisplayName":"tester",
		"contactStatus":"active"}},"chatItems":[` + strings.Join(items, ",") + `],
		"chatStats":{"unreadCount":0,"minUnreadItemId":0,"unreadChat":false}},
		"navInfo":null}`
}

// describe sums up a chat item as its id, content type, message if it
// has one, and time.
func describe(item simplex.ChatItem) string {
	s := strconv.FormatInt(item.Meta.ItemID, 10) + " " + item.Content.Type

	if m := item.Content.MsgContent; m != nil {
		s += " " + m.Type + " " + strconv.Quote(m.Text)
	}

	return s + " " + item.Meta.ItemTs.Format(time.RFC3339Nano)
}

// TestChatItems: the chat's last items come back oldest first, read five
// at a time from the newest backwards, and reading stops at the start
// of the chat.
func TestChatItems(t *testing.T) {
	t.Parallel()

	f, url := newFakeChat(t, map[string]string{
		"/_get chat @3 count=5": apiChat(
			itemGreeting, itemText, itemFormatted, itemPicture, itemSent),
		"/_get chat @3 before=8 count=2": apiChat(itemEvent),
	})
	c, ctx := dial(t, url, nil)

	items, err := c.ChatItems(ctx, 3, 7)
	if err != nil {
		t.Fatalf("ChatItems: %v", err)
	}

	for _, want := range []string{
		"/_get chat @3 count=5",
		"/_get chat @3 before=8 count=2",
	} {
		if got := f.next(t); got != want {
			t.Errorf("command = %s, want %s", got, want)
		}
	}

	want := []string{
		`7 rcvChatFeature 2026-09-29T03:13:46.521359978Z`,
		`8 sndMsgContent text "hi" 2026-09-29T03:13:46.925072391Z`,
		`9 rcvMsgContent text "2 + 2" 2026-09-29T03:14:34Z`,
		`10 rcvMsgContent text "*bold* and _italic_" 2026-09-29T03:14:34Z`,
		`11 rcvMsgContent image "a picture" 2026-09-29T03:14:34Z`,
		`12 sndMsgContent text "hello from the API" 2026-09-29T03:14:43.519552587Z`,
	}

	got := make([]string, 0, len(items))
	for _, item := range items {
		got = append(got, describe(item))
	}

	if !slices.Equal(got, want) {
		t.Errorf("ChatItems =\n%s\nwant\n%s",
			strings.Join(got, "\n"), strings.Join(want, "\n"))
	}
}

// TestSendMessage: a text goes out as /_send, and comes back as the chat
// client recorded it.
func TestSendMessage(t *testing.T) {
	t.Parallel()

	f, url := newFakeChat(t, map[string]string{"/_send": sentItems})
	c, ctx := dial(t, url, nil)

	item, err := c.SendMessage(ctx, 3, "hello from the API")
	if err != nil {
		t.Fatalf("SendMessage: %v", err)
	}

	want := `/_send @3 json [{"msgContent":{"type":"text",` +
		`"text":"hello from the API"},"mentions":{}}]`
	if got := f.next(t); got != want {
		t.Errorf("command = %s\nwant      %s", got, want)
	}

	wantItem := `12 sndMsgContent text "hello from the API" ` +
		`2026-09-29T03:14:43.519552587Z`
	if got := describe(item); got != wantItem {
		t.Errorf("SendMessage = %s, want %s", got, wantItem)
	}
}

// TestRefusals: the chat client's refusals that callers answer for come
// back as this package's errors, still carrying the chat client's
// reason.
func TestRefusals(t *testing.T) {
	t.Parallel()

	for name, tc := range map[string]struct {
		record string
		read   bool // ChatItems rather than SendMessage
		want   error
	}{
		"reading, no such contact": {contactNotFound, true, simplex.ErrNoContact},
		"sending, no such contact": {contactNotFound, false, simplex.ErrNoContact},
		"sending, contact deleted": {contactNotReady, false, simplex.ErrContactNotReady},
		"sending, text too long":   {largeMsg, false, simplex.ErrMessageTooLarge},
	} {
		t.Run(name, func(t *testing.T) {
			t.Parallel()

			_, url := newFakeChat(t, map[string]string{
				"/_get": tc.record, "/_send": tc.record,
			})
			c, ctx := dial(t, url, nil)

			var err error
			if tc.read {
				_, err = c.ChatItems(ctx, 4, 20)
			} else {
				_, err = c.SendMessage(ctx, 4, "hi")
			}

			var cerr *simplex.CommandError
			if !errors.Is(err, tc.want) || !errors.As(err, &cerr) {
				t.Errorf("error = %v, want %v with the chat client's reason", err, tc.want)
			}
		})
	}
}