Shanghai ascii game sticks

Question

Remove one stick and output the stack updated.

Description

You can remove only sticks on top( completely drawn).

You can assume:

• there are 5 sticks on the table.
• there's one and only one stick you can remove.
• sticks are recognizable : there aren't overlapping sticks on the same orientation and there aren't sticks joined which form a longer line.
• input should be not ambiguous, there should be only one valid solution as pointed out by @Arnauld comment, for example this input is not valid
• Trailing /leading spaces doesn't matter.

Sticks are 4 chars long and are placed vertically or horizontally.

 | ————
 |
 | 
 |

Test cases [Before, after]

[" 
 ||| 
 —|—— 
 ||| 
 |||— 
 ",
" 
 | | 
 ———— 
 | | 
 |—|— 
 "],
[" 
 ||| 
 —|—— 
 ||| 
 |||—— 
 
 ",
" 
 | | 
 ———— 
 | | 
 |—|—— 
 
 "],
[" 
 ||| 
 —|—— 
 ||| 
 |||——— 
 
 ",
" 
 | | 
 ———— 
 | | 
 | |——— 
 
 "],
[" 
 | 
 ———| 
 |——— 
 | | 
 |———— 
 ",
" 
 | 
 ———| 
 |——— 
 | | 
 | 
 "],
[" 
 | 
 | 
 | 
 ———— 
 | | 
 | | 
 |——— 
 | 
 ",
" 
 | 
 | 
 | 
 || 
 | | 
 | | 
 |——— 
 | 
 "],
[" 
 
 | 
 ———— 
 ——|— 
 |——— 
 | 
 
 
 ",
" 
 
 | 
 | | 
 ——|— 
 |——— 
 | 
 
 
 "],
[" 
 
 | | 
 ————| 
 | |——— 
 | | | 
 | 
 
 ",
" 
 
 | | 
 | | | 
 | |——— 
 | | | 
 | 
 
 "],
[" 
 
 ———| 
 ——|— 
 —|—— 
 |——— 
 
 
 ",
" 
 
 ———— 
 ———— 
 ———— 
 ———— 
 
 
 "],
[" 
 | 
 —||— 
 || 
 ———— 
 | | 
 | 
 | 
 ",
" 
 | 
 —||— 
 || 
 ||| 
 | | 
 | 
 | 
 "],
[" 
 
 |——— | 
 | | | 
 | | | 
 ———| | 
 
 ",
" 
 
 |——— 
 | | 
 | | 
 ———| 
 
 "]

Input specifications
You can add trailing and leading whitespaces / lines as your wish, , I hope this can help focusing on the task by avoiding data bounds checking.

here is a small program to get input data in some formatting. In the header section you can change some characters like array bounds and others.
Data is in the form of a square matrix and the image is surrounded by whitespaces.

Rules

• Input/output can be given by any convenient method.
• You can print it to STDOUT, return it as a function result or error message/s.
• Either a full program or a function are acceptable.
• Standard loopholes are forbidden.
• This is code-golf so all usual golfing rules apply, and the shortest code (in bytes) wins.

Sandbox

Answer 1

Charcoal, 102 bytes

×ばつ§-|¬η4F4↓§ -⊙EErlKDχ✳κ...κ⌕Eκ›μ 0∧›5LκNoκ-¿η‖T↗

Try it online! Link is to verbose version of code. Takes input as a list of strings containing spaces, minus signs or pipes. Explanation:

WS⊞υι

Input the game.

υ

Output the game to the canvas.

×ばつ-4η≔Σηζ

Try to locate a horizontal stick.

¿η

If one was found, then...

‖T↗

... reflect the canvas transforming between minus signs and pipes, ...

«

Otherwise, ...

≔Eθ⭆υ§λκυ

... transpose the game array (sadly without transforming), ...

×ばつ|4ζ

... and find a vertical stick.

×ばつ§-|¬η4

Jump to the stick's current location on the canvas.

F4↓§ -⊙EErlKDχ✳κ...κ⌕Eκ›μ 0∧›5LκNoκ-

Overwrite the pipes of the (possibly transformed) stick with spaces, unless there are at most four consecutive non-blank characters (including the pipe itself) including at least one minus sign on at least one side of the pipe, in which case overwrite with a minus sign instead.

¿η‖T↗

Transform the canvas back if necessary before it's implicitly printed.

• l4m2: Fail it turns into a 5 char long stick
• Neil: @l4m2 Thanks; I've implemented a completely different algorithm now.
• tsh: I want try this testcase, but I don't know how to make it work. Should I padding some more spaces around?
• Neil: @tsh Sorry, I got bit by Charcoal behaviour. It's very difficult to use if because the else is implicit (verbose mode lets you drop the else but it's still there really) so if I don't want an else then I use a for loop instead, but then that reallocates the implicit for variables... anyway, should be fixed now.