Refactor alliance storage to use a single object per alliance instead of one per alliance-team association.

model/alliance.go

@@ -0,0 +1,84 @@
+// Copyright 2022 Team 254. All Rights Reserved.
+// Author: pat@patfairbank.com (Patrick Fairbank)
+//
+// Model and datastore CRUD methods for a playoff alliance.
+
+package model
+
+import "sort"
+
+type Alliance struct {
+	Id      int `db:"id,manual"`
+	TeamIds []int
+	Lineup  [3]int
+}
+
+func (database *Database) CreateAlliance(alliance *Alliance) error {
+	return database.allianceTable.create(alliance)
+}
+
+func (database *Database) GetAllianceById(id int) (*Alliance, error) {
+	return database.allianceTable.getById(id)
+}
+
+func (database *Database) UpdateAlliance(alliance *Alliance) error {
+	return database.allianceTable.update(alliance)
+}
+
+func (database *Database) DeleteAlliance(id int) error {
+	return database.allianceTable.delete(id)
+}
+
+func (database *Database) TruncateAlliances() error {
+	return database.allianceTable.truncate()
+}
+
+func (database *Database) GetAllAlliances() ([]Alliance, error) {
+	alliances, err := database.allianceTable.getAll()
+	if err != nil {
+		return nil, err
+	}
+	sort.Slice(alliances, func(i, j int) bool {
+		return alliances[i].Id < alliances[j].Id
+	})
+	return alliances, nil
+}
+
+// Returns two arrays containing the IDs of any teams for the red and blue alliances, respectively, who are part of the
+// elimination alliance but are not playing in the given match.
+// If the given match isn't an elimination match, empty arrays are returned.
+func (database *Database) GetOffFieldTeamIds(match *Match) ([]int, []int, error) {
+	redOffFieldTeams, err := database.getOffFieldTeamIdsForAlliance(
+		match.ElimRedAlliance, match.Red1, match.Red2, match.Red3,
+	)
+	if err != nil {
+		return nil, nil, err
+	}
+
+	blueOffFieldTeams, err := database.getOffFieldTeamIdsForAlliance(
+		match.ElimBlueAlliance, match.Blue1, match.Blue2, match.Blue3,
+	)
+	if err != nil {
+		return nil, nil, err
+	}
+
+	return redOffFieldTeams, blueOffFieldTeams, nil
+}
+
+func (database *Database) getOffFieldTeamIdsForAlliance(allianceId int, teamId1, teamId2, teamId3 int) ([]int, error) {
+	if allianceId == 0 {
+		return []int{}, nil
+	}
+
+	alliance, err := database.GetAllianceById(allianceId)
+	if err != nil {
+		return nil, err
+	}
+	offFieldTeamIds := []int{}
+	for _, allianceTeamId := range alliance.TeamIds {
+		if allianceTeamId != teamId1 && allianceTeamId != teamId2 && allianceTeamId != teamId3 {
+			offFieldTeamIds = append(offFieldTeamIds, allianceTeamId)
+		}
+	}
+	return offFieldTeamIds, nil
+}