Implement Trade view

[TimDaub]

Scope

• In "Planet A" two players can trade.

• A trade emits CO2

• CO2 is tracked on a per-player basis. Essentially each player will have a CO2 score

• The trading process works as follows:

  • Two players (A and B) meet in real life and talk about the game
  • Player A asks Player B to trade within the game
  • To initiate the trade, Player A selects "trade" from their wallet. The wallet generates a QR code
  • If Player B decides to accept the trade of Player A, then some goods are exchanged between the two, CO2 is globally emitted ("into the air") and also credited to their individual balance

  "Mechanics"

• From the testing a light version of the game, it became clear that the following things make trading more fun:

  • knowing the other players Goellars, Plants and CO2 balance
  • being able to assume how the other player got their Goellars, Plants, CO2 (e.g. do some players wash their balances green?)
  • Players shouldn't constantly be able to trade. Instead there should be a cool down. If that turns out to be difficult to implement within the time frame of the Ethereum meetup, a simple frontend block might be sufficient to test the idea

Deliverables

• Build a trade view according to the specifications above

Note

• The trade view will be one of the first views, we want a user to explore. It should hence be "easily accessible" to the user in terms of usability. Meaning it should be simple and "intuitive" to use.
• **Please note that since @johannbarbie is not available in the week of the meetup, this issue as special priority to be completed before July 19th, Friday.

Roles

bounty gardener: @TimDaub / 10% bounty worker: name / 75% bounty reviewer: name / 15%

[johannbarbie]

here are some more details in the mock: https://docs.google.com/drawings/d/1rcTgrE9ZsbClerhOGthGe9J6eLHYrQnq7ZJp8h7mwYs

[vrde]

Unit test that implements this functionality.

[johannbarbie]

Spec for QR code generation:

1. query getUnspent(citizenAddr, passportColor) and read first passport data as dataBefore.
2. update CO2 in passport data as dataAfter.
3. create sig by ecsign(hashPersonalMessage(dataBefore, dataAfter), PRIV).
4. concatenate | 2 bytes passportColor | 20 bytes citizenAddr | 32 bytes dataAfter | 32 bytes sigR | 32 bytes sigS | 1 byte sigV |.
5. build URL https://toco2.leap.rocks/trade#<119 bytes receipt encoded as base64 url (rfc4648)>.

Spec for scanning and verifying QR code:

1. scan URL, extract passportColor, citizenAddr, dataAfter and sig.
2. query getUnspent(citizenAddr, passportColor), take first result, read data as dataBefore.
3. ecrecover(hashPersonalMessage(dataBefore, dataAfter)) and compare to citizenAddr, should match.
4. use sig and dataAfter in transaction payload.