This song by Bruno Mars is in F.
These are the “cheat” chords I played…
Part 1a: Dm - Am
Part 1b: same as Part 1a
Part 2a: same as Part 1a
Part 2b: Dm - Bb - A
Part 3a: Dm - Bb - F - C
Part 3b: same as Part 3a
Part 3c: same as Part 3a
Part 3d: same as Part 3a
Part 4a: Bb - C
Part 4b: F - A - Dm - C
Part 4c: Bb - A
Part 5a: Gm - Dm
Part 5b: Gm - A
Part 5c: Dm - Bb - A