package gallerydl

import (
	"context"
	"errors"
	"os"
	"path/filepath"
	"strings"
	"testing"

	"git.nakama.town/fmartingr/butterrobot/internal/model"
)

// fakeDownloader returns a Downloader that optionally writes a file and/or
// returns an error, and records whether it was called and with which URL.
func fakeDownloader(writeFile bool, returnErr error, gotURL *string) Downloader {
	return func(ctx context.Context, binPath, destDir, url string) error {
		if gotURL != nil {
			*gotURL = url
		}
		if writeFile {
			_ = os.WriteFile(filepath.Join(destDir, "media.jpg"), []byte("data"), 0o600)
		}
		return returnErr
	}
}

func newMessage(text, author, replyTo string, raw map[string]interface{}) *model.Message {
	return &model.Message{
		Text:    text,
		Author:  author,
		Chat:    "chat1",
		ID:      "msg1",
		ReplyTo: replyTo,
		Raw:     raw,
		Channel: &model.Channel{Platform: "telegram", PlatformChannelID: "chat1"},
	}
}

func telegramReplyRaw(originalText string) map[string]interface{} {
	return map[string]interface{}{
		"message": map[string]interface{}{
			"reply_to_message": map[string]interface{}{
				"text": originalText,
			},
		},
	}
}

func TestOnMessage(t *testing.T) {
	allowed := map[string]interface{}{"allowed_users": "alice, bob"}

	tests := []struct {
		name         string
		msg          *model.Message
		config       map[string]interface{}
		writeFile    bool
		downloadErr  error
		wantActions  int
		wantType     model.ActionType
		wantReplyTo  string
		wantText     string // substring expected in a text reply (if any)
		wantDownload bool
		wantDownURL  string
	}{
		{
			name:        "not the command",
			msg:         newMessage("hello there", "alice", "", nil),
			config:      allowed,
			wantActions: 0,
		},
		{
			name:        "deny by default (empty allowlist)",
			msg:         newMessage("!gallerydl https://example.com/x", "alice", "", nil),
			config:      map[string]interface{}{},
			wantActions: 1,
			wantType:    model.ActionSendMessage,
			wantText:    "not allowed",
		},
		{
			name:        "deny user not in allowlist",
			msg:         newMessage("!gallerydl https://example.com/x", "carol", "", nil),
			config:      allowed,
			wantActions: 1,
			wantType:    model.ActionSendMessage,
			wantText:    "not allowed",
		},
		{
			name:         "authorized with URL in message",
			msg:          newMessage("!gallerydl https://example.com/gallery/1", "alice", "", nil),
			config:       allowed,
			writeFile:    true,
			wantActions:  1,
			wantType:     model.ActionSendMedia,
			wantReplyTo:  "msg1",
			wantDownload: true,
			wantDownURL:  "https://example.com/gallery/1",
		},
		{
			name:         "authorized with URL from replied-to message",
			msg:          newMessage("!gallerydl", "bob", "orig99", telegramReplyRaw("look https://example.com/gallery/2 nice")),
			config:       allowed,
			writeFile:    true,
			wantActions:  1,
			wantType:     model.ActionSendMedia,
			wantReplyTo:  "orig99",
			wantDownload: true,
			wantDownURL:  "https://example.com/gallery/2",
		},
		{
			name:         "authorized via @-prefixed allowlist entry",
			msg:          newMessage("!gallerydl https://example.com/z", "alice", "", nil),
			config:       map[string]interface{}{"allowed_users": "@Alice"},
			writeFile:    true,
			wantActions:  1,
			wantType:     model.ActionSendMedia,
			wantReplyTo:  "msg1",
			wantDownload: true,
		},
		{
			name:        "authorized but no link",
			msg:         newMessage("!gallerydl", "alice", "", nil),
			config:      allowed,
			wantActions: 1,
			wantType:    model.ActionSendMessage,
			wantText:    "No link found",
		},
		{
			name:         "download error",
			msg:          newMessage("!gallerydl https://example.com/x", "alice", "", nil),
			config:       allowed,
			downloadErr:  errors.New("boom"),
			wantActions:  1,
			wantType:     model.ActionSendMessage,
			wantText:     "Download failed",
			wantDownload: true,
		},
		{
			name:         "nothing downloaded",
			msg:          newMessage("!gallerydl https://example.com/x", "alice", "", nil),
			config:       allowed,
			writeFile:    false,
			wantActions:  1,
			wantType:     model.ActionSendMessage,
			wantText:     "Nothing was downloaded",
			wantDownload: true,
		},
	}

	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			p := New()
			var gotURL string
			p.download = fakeDownloader(tt.writeFile, tt.downloadErr, &gotURL)

			actions := p.OnMessage(tt.msg, tt.config, nil)

			if len(actions) != tt.wantActions {
				t.Fatalf("got %d actions, want %d", len(actions), tt.wantActions)
			}
			if tt.wantActions == 0 {
				if gotURL != "" {
					t.Errorf("downloader should not have run, got url %q", gotURL)
				}
				return
			}

			action := actions[0]
			if action.Type != tt.wantType {
				t.Fatalf("got action type %q, want %q", action.Type, tt.wantType)
			}

			switch action.Type {
			case model.ActionSendMedia:
				if action.Message.ReplyTo != tt.wantReplyTo {
					t.Errorf("ReplyTo = %q, want %q", action.Message.ReplyTo, tt.wantReplyTo)
				}
				if len(action.Message.Files) == 0 {
					t.Errorf("expected media files, got none")
				}
				if dir, ok := action.Message.Raw["cleanup_dir"].(string); !ok || dir == "" {
					t.Errorf("expected cleanup_dir in Raw, got %v", action.Message.Raw)
				} else {
					t.Cleanup(func() { _ = os.RemoveAll(dir) })
				}
			case model.ActionSendMessage:
				if tt.wantText != "" && !strings.Contains(action.Message.Text, tt.wantText) {
					t.Errorf("reply text %q does not contain %q", action.Message.Text, tt.wantText)
				}
			}

			if tt.wantDownload {
				if gotURL == "" {
					t.Errorf("expected downloader to run, but it did not")
				}
				if tt.wantDownURL != "" && gotURL != tt.wantDownURL {
					t.Errorf("downloaded url = %q, want %q", gotURL, tt.wantDownURL)
				}
			} else if gotURL != "" {
				t.Errorf("downloader should not have run, got url %q", gotURL)
			}
		})
	}
}