package logic

import "testing"

func TestValidateYarnRatio(t *testing.T) {
	tests := []struct {
		name    string
		raw     string
		wantErr bool
	}{
		{
			name:    "empty ratio is valid",
			raw:     "",
			wantErr: false,
		},
		{
			name:    "both sides add up to ten",
			raw:     `{"warp":[{"yarn_id":"y1","ratio":6},{"yarn_id":"y2","ratio":4}],"weft":[{"yarn_id":"y3","ratio":10}]}`,
			wantErr: false,
		},
		{
			name:    "one empty side is valid",
			raw:     `{"warp":[{"yarn_id":"y1","ratio":10}],"weft":[]}`,
			wantErr: false,
		},
		{
			name:    "side with yarn must add up to ten",
			raw:     `{"warp":[{"yarn_id":"y1","ratio":9}],"weft":[]}`,
			wantErr: true,
		},
		{
			name:    "ratio must be integer",
			raw:     `{"warp":[{"yarn_id":"y1","ratio":9.5}],"weft":[]}`,
			wantErr: true,
		},
		{
			name:    "yarn id is required",
			raw:     `{"warp":[{"ratio":10}],"weft":[]}`,
			wantErr: true,
		},
		{
			name:    "invalid json is rejected",
			raw:     `{warp}`,
			wantErr: true,
		},
	}

	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			err := validateYarnRatio(tt.raw)
			if (err != nil) != tt.wantErr {
				t.Fatalf("validateYarnRatio() error = %v, wantErr %v", err, tt.wantErr)
			}
		})
	}
}