Description of Company and Basis of Presentation (Details - Consolidated balance sheet) - USD ($) $ in Thousands	Oct. 31, 2023	Jul. 31, 2023	Apr. 30, 2023	Oct. 31, 2022	Jul. 31, 2022	Apr. 30, 2022
Current assets:
Cash and cash equivalents	$ 31,424		$ 38,542	$ 77,292		$ 126,166
Accounts receivable, net	13,379		18,298
Contract assets	10,847		9,609
Inventory	38,583		43,908
Prepaid expenses and other current assets	9,972		2,094
Total current assets	104,205		112,451
Property and equipment, net	187,874		177,770
Operating lease right-of-use assets	41,973		42,772
Deferred tax assets	116,760		113,751
Other assets	4,673		4,473
Total assets	455,485		451,567
Current liabilities:
Accounts payable	22,784		24,593
Accrued compensation and benefits	4,244		8,780
Contract liabilities	46,437		37,352
Convertible senior notes, net	141,154
Current portion of operating lease liabilities	1,263		1,358
Other current liabilities	3,394		2,440
Total current liabilities	219,276		215,146
Convertible senior notes, net	0
Operating lease liabilities, less current portion	45,036		45,690
Finance lease liabilities, less current portion	7,840		1,562
Total liabilities	272,152		262,398
Commitments and contingencies
Stockholders’ equity:
Preferred stock, $0.001 par value; 5,000 shares authorized; no shares issued and outstanding at respective dates	0		0
Common stock, $0.001 par value; 150,000 shares authorized; 63,234 and 62,692 shares issued and outstanding at respective dates	63		63
Additional paid-in capital	626,031		620,224
Accumulated deficit	(442,761)		(431,118)
Total stockholders’ equity	183,333	$ 190,268	189,169	$ 181,628	$ 178,796	$ 174,526
Total liabilities and stockholders’ equity	455,485		451,567
Previously Reported [Member]
Current assets:
Cash and cash equivalents	31,424
Accounts receivable, net	13,379
Contract assets	10,847
Inventory	38,583
Prepaid expenses and other current assets	9,972
Total current assets	104,205
Property and equipment, net	187,174
Operating lease right-of-use assets	41,973
Deferred tax assets	116,617
Other assets	4,673
Total assets	454,642
Current liabilities:
Accounts payable	22,784
Accrued compensation and benefits	4,244
Contract liabilities	46,437
Convertible senior notes, net	0
Current portion of operating lease liabilities	1,263
Other current liabilities	2,209
Total current liabilities	76,937
Convertible senior notes, net	141,154
Operating lease liabilities, less current portion	45,036
Finance lease liabilities, less current portion	7,840
Total liabilities	270,967
Commitments and contingencies
Stockholders’ equity:
Preferred stock, $0.001 par value; 5,000 shares authorized; no shares issued and outstanding at respective dates	0
Common stock, $0.001 par value; 150,000 shares authorized; 63,234 and 62,692 shares issued and outstanding at respective dates	63
Additional paid-in capital	626,031
Accumulated deficit	(442,419)
Total stockholders’ equity	183,675	190,598	189,470
Total liabilities and stockholders’ equity	454,642
Revision of Prior Period, Adjustment [Member]
Current assets:
Cash and cash equivalents	0
Accounts receivable, net	0
Contract assets	0
Inventory	0
Prepaid expenses and other current assets	0
Total current assets	0
Property and equipment, net	700
Operating lease right-of-use assets	0
Deferred tax assets	143
Other assets	0
Total assets	843
Current liabilities:
Accounts payable	0
Accrued compensation and benefits	0
Contract liabilities	0
Convertible senior notes, net	141,154
Current portion of operating lease liabilities	0
Other current liabilities	1,185
Total current liabilities	142,339
Convertible senior notes, net	(141,154)
Operating lease liabilities, less current portion	0
Finance lease liabilities, less current portion	0
Total liabilities	1,185
Commitments and contingencies
Stockholders’ equity:
Preferred stock, $0.001 par value; 5,000 shares authorized; no shares issued and outstanding at respective dates	0
Common stock, $0.001 par value; 150,000 shares authorized; 63,234 and 62,692 shares issued and outstanding at respective dates	0
Additional paid-in capital	0
Accumulated deficit	(342)
Total stockholders’ equity	(342)	$ (330)	$ (301)
Total liabilities and stockholders’ equity	$ 843