Box score trade ledger

Build season scoring totals for a basketball league where players get traded mid-season.

You are given the opening rosters as [player, team] pairs, the season's trades as [day, player, new_team], and the lines of the box scores as [day, player, minutes, points]. Days are integers.

• A trade on day d takes effect from day d + 1: games played on day d still count for the old team. Several trades of the same player can occur; apply them in order of day, and for the same day in the order they are listed (the later one wins).
• A line's team is the player's team on that line's day. Lines for players who are not on the opening rosters are ignored.
• If the same player has more than one line on the same day, the last one listed replaces the earlier ones (a stat correction).
• A line with minutes == 0 means the player did not play: it adds no game and no points. Every other line is one game played, and its points are added.

Input: rosters, trades and lines, as above.

Output: one row [player, team, games, points] for every (player, team) pair with at least one game, ordered by points descending, then by player ascending, then by team ascending. Names compare by plain alphabetical (code point) order.