Flight Attendant reported they were informed that the aircraft had no power and there was smoke in the cabin. The flight continued to destination and landed safely.

Narrative

During the service the Purser; who was working the top of the beverage left the cart to go pass the pilots their meals. The cockpit had a jump seater so it wasn't necessary however he went. I continued on with the service without him. At some point the galley flight attendant came up to join me on the cart. Around row XX a passenger told us the power on her tv went out. We looked around and saw all the tvs were out. We continued doing the service. At another point I went to the back galley to get more coffee. The jump seater decided to help us with the service because I told her I had no idea what was going on the two flight attendants were just standing at the forward galley. I go back to the cart and then noticed the cockpit door was wide open. We were finishing the service. The cockpit door was still open. The jump seater told me that we might deviate because the power was out and the cabin was hot. I went up to the forward galley to figure out why the cockpit door was wide open and why both flight attendants were standing while we continued working. When I asked the FA's (Flight Attendant) what was going on the Captain appeared around the corner aggressively saying Once we know what's going we will tell you." I said "Well you know something but nothing has been communicated to the working crew…."He yelled "Ma'am this doesn't concern you"I said "Ma'am? I am your working crew" (The Captain didn't do a briefing or introduce himself to the crew) I also continued on "I wasn't addressing you; I'm talking to the flight attendants trying to figure out why they didn't help us with the service" that's when the purser finally told me the we might deviate and there was smoke in the cabin and they were dealing with a potential emergency situation. I made my way back to the back galley. The Captain called asking for the "Deadheading Flight Attendant A" (Flight Attendant A is on my wings my middle name) I talked to the pilot and he continued asking me about the "deadheading FA" but he was talking to me I again told him I am your working crew….I didn't communicate with him further. He asked for the purser. We landed in ZZZ safely. I was told the jumpseating pilot would occupy the jumpseat in the front and the flight attendant would come to the back for landing. (Person A and I switched positions on this leg.)Communication was completely lacking between both the flight deck and the Purser. It seems like the forward working flight attendants thought they were talking to the working crew but they weren't. The reason behind my "attitude" was I was worried for the safety of myself and everyone on board when I saw the cockpit door open for WAY longer than 3 seconds. With only one Pilot in the flight deck at the time. The Captain was outside of the cockpit as well as the jump seater and If I had to count; I would say it was open for 5 minutes with no communication to me as to whyAfter the flight the Captain pulled me for a conversation I asked for a supervisor to join us he said he wanted to resolve it between us. (There was a gate agent supervisor present at the time I asked her to call for the cabin crew department. She called once the Captain said no supervisors I told her she could disconnect the call) I told him everything from my perspective; he said he was having a bad day when he first approached me and admitted that it was wrong. He told me what happened and the reason why he was out of the cockpit he said there was smoke in the cabin; which is the first time I heard this. (I was told that the Cabin was too hot or that the cabin walls were too hot) I was then informed that the cockpit door was open for light in galley. He said they were going through a checklist which is why they couldn't tell us what was happening. He said he felt like it was resolved between us and apologized 'if I felt offended' and didn't need to escalate it. I'm not sure what he meant but I did inform him that I wrote a report already and his demeanor changed he no longer seemed approachable or open to the conversation- he then said I came up and 'made things worse' I'm not sure how me addressing the flight attendants to figure out what was going on could have made the situation worse. He implied that I interpreted a conversation however as I approached the forward galley; I didn't know the Captain was in the galley until he yelled at me. Which shocked me to find him out of the cockpit; but I told him despite that I felt like it was important for me to write the report he said he didn't agree. I offered to show him my report. He declined. I walked away."