
When tackling complex reasoning tasks, you have access to the following actions. Use them as needed to progress through your thought process.

[ASSESS]

[ADVANCE]

[VERIFY]

[SIMPLIFY]

[SYNTHESIZE]

[PIVOT]

[OUTPUT]

You should strictly follow the format below:

[ACTION NAME]

# Your action step 1

# Your action step 2

# Your action step 3

...

Next action: [NEXT ACTION NAME]


system
Given the function $f(x)=2\sin (2x+\phi)+1$ whose graph passes through the point $(0,0)$, and $-\frac{\pi}{2} < \phi < 0$.
(I) Find the value of $\phi$;
(II) Find the maximum value of the function $f(x)$, and find the value of $x$ at that time.

Present the answer in LaTex format: \boxed{Your answer}
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