Notice that the verb tense which follows 'I wish' is 'more in the past' than the tense corresponding to its meaning.

In the case of 'will' , where 'will' means 'show willingness' we use 'would'.

Where 'will' means a future event, we cannot use 'wish' and must use 'hope'.

In more formal English, we use the subjunctive form 'were' and not 'was' after 'wish'.