[14.0][IMP] l10n_th_withholding_tax, Add PIT feature.

[kittiu]

This PR do not change any logic in calculate WHT. But add a useful field "Withholding Base Amount", and as such, it is now possible to change base amount in order to calculate back the withholding tax.

[kittiu]

@Saran440 can you help review this one please.

[Saran440]

@kittiu
On wizard. Fields Amount + Payment Difference must equal Withholding Base always?
if yes, you should add function for check this.

[kittiu]

@kittiu On wizard. Fields Amount + Payment Difference must equal Withholding Base always? if yes, you should add function for check this.

No, not necessary. It is possible that, only 1 out of 2 invoice line is the base amount. I do this intentionally.
Also, even if in invoice line, there are not WHT lines, we can still select the WHT in payment wizard and type in base amount manually.

Now, it is very flexible.

[Saran440]

Functional Test,
Vat + WT -> 👍
WT only -> 👍

[kittiu]

@saran, as discussed,

• I moved PIT feature from [14.0][ADD] l10n_th_withholding_tax_pit #261 here.
• Except "Create Cert.", I will create another PR for l10n_th_withholding_tax_cert
• I will also create PR for l10n_th_withholding_tax_multi to make it support PIT too.

Please help review/approve this PR, and we will continue with the rest.

[kittiu]

Ready for review.

[kittiu]

@Saran440 @ps-tubtim This PR is ready for review.

[Saran440]

Functional Test

Case: Cancel Payment with PIT

1. Create Vendor Bills and select line with PIT > Register Payment normal process
2. View PIT on vendor (it's correct)
   
3. Cancel Payment and View PIT on vendor again
   

Should be check cancel checkbox?
and I test payment reset to draft and cancel again.
It reversed and not check cancel last line.

---

Case: Some field is not used

1. Payment View
   

2. Vendor View
   

[Saran440]

Review above

[peerayaproud]

I would like to raise issue about employee expense
If the employee made an expense report and there is PIT.
The Odoo will record PIT data in "that employee" master data not the vendor who got paid from employee.
Also the WHT Certificate will print employee's name.
The employee is just a middle man who transfer company's money to Vendor.

[newtratip]

@kittiu, Could you fix the conflict files ?

[kittiu]

TODO:

• Fix the reported bugs (above)
• Make sure that, when this module works with expense and clearing (and l10n_th_expense_tax), it use correct bill_partner_id when withhold.
• (not this PR), Fix for normal Tax Invoice, currently, the module l10n_th_expense_tax invoice should also dr/cr on bill_partner_id

@Saran440

[kittiu]

Review above

Note on the Type of Income, it is intentional to have user fill it later one (just before printing cert is ok).

[kittiu]

Closed as move to #272