A man accused of plotting a mass casualty terror attack targeting public buildings and places of worship believed his assault would be worse than the Bondi beach mass shootings, a court has heard.

Jayson Joseph Michaels detailed his alleged plan for a violent assault on Western Australia police headquarters, WA Parliament House and mosques in a diary, the Perth magistrates court was told during a failed bid for bail on Wednesday.

The 20-year-old is facing five charges, including acting in preparation for a terrorist act, after police seized the diary during a raid on his parents’ home in the town of Bindoon, north of Perth, in February.

It contained entries that amounted to a list of actions Michaels planned to undertake, including making weapons and body armour for a “day of justice,” commonwealth prosecutor Kirsten Nelson said.

“The diary is a clear expression of his intent to engage in a terrorist act,” she said.

Michaels, who appeared in court via video link from Casuarina prison sporting a chin beard and long hair past his shoulders, allegedly planned to buy a 3D printer to make a gun and got a job where he could access bomb-making materials, but left empty-handed after one day.

He also compared the Bondi beach attack to his own terror plot and wrote notes about how it might impact it, Nelson said.

“What I want to do to both these groups pales in comparison to today,” he allegedly wrote after the 14 December shootings that killed 15 and injured many more.

“What will they all think when my face is on TV?” he allegedly wrote.

Michaels allegedly accessed online material about extremist white supremacist ideology, some of which was described as a manifesto and instruction manual from a declared terrorist organisation.

He wrote about researching entry points and door locks at his target locations and considered using a van that looked like an ambulance to make his escape, Nelson said.

He also allegedly penned a notes about buying a ballistic helmet, designing and building body armour or an Iron Man-style metal suit.

“I think I’m addicted to the [Watch People Die] website,” he allegedly wrote in another diary entry.

The website was open on his computer when police burst into his room, the court has heard.

Michaels’ defence lawyer, former federal attorney general Christian Porter, said his client was an isolated and depressed young man who had no intention to carry out the plan.

“This was a pie-in-the-sky dream,” he said.

“A Walter Mitty-esque fantasy.”

Michaels’ diary had “all the hallmarks of a Marvel comic,” Porter said.

“He is revealed in this diary as a pretender full of big talk,” he said.

The crown’s case is weak because it relies on the diary, Porter said.

Magistrate Belinda Coleman said the diary, found in a locked drawer, had “disturbing” entries and were not just “ramblings”.

“It was chilling material,” with derogatory references to various ethnic groups, she said.

Michaels also had two guns, 900 rounds of ammunition and various knives in his bedroom, she said as she refused bail.

Michaels is yet to enter pleas and due to face Stirling Gardens magistrates court on 13 May.