ASA airdrops and Open sale for Algos

We have created an ASA, and we have the following requirements, request a suitable approach to achieve the functionality.

  1. Sale of ASA for Algos: User should be able to send x Aglos receive x ASA tokens as per the sale schedule.
  2. Recieve airdrop of xASA tokens as per specific schedule for every unique wallet address.

To acheive the above functionalities, whats the best approach. Any one who can suggest a suitable approach in the above requirement appreciated.

Welcome to Algorand!

For the first part, you can use GitHub - algorandfoundation/buildweb3: Repository for the Algorand class of the "Building with Blockchain for Web 3.0" course (https://buildweb3.org) (you need to read the previous parts which also give an introduction to Algorand and ASA).

For the second part, the receiver must opt-in to the ASA before being able to receive it. They must buy some Algos for that purpose and then send an opt-in transactions. You may also consider sending them 0.201 Algo for that purpose. But they would still need to sign the opt-in transaction.
Once opt-in is dealt with, you can just send the ASA airdrop using a scripts generating and signing those transactions.

Is opt-in via algosigner and to participate is airdrop is possible through algosigner?

For example to participate in open sale, sign via algosigner, and
To participate in airdrop sign via algo signer is possible.

We wanted to airdrop to every unique Algorand address.

Yes, algosigner can sign any transaction including opt-in.

To airdrop to every unique Algorand address, you may consider having an off-chain server signing the airdrop transaction to users that are interested, and exclude addresses that have been created too recently.
Otherwise, a user can create many addresses to get many times the airdrop.