#https://marketplace.visualstudio.com/items?itemName=davidnussio.vscode-jq-playground

## Just saying Hi
jq .
"Hello JSON Lovers"

## Displaying contents of demo.json with pretty output
jq -r .
./demo.json

## Get the count of Total Documents
jq -r '.|length' 
./demo.json

## Get the number of elements in first document.
jq -r '.[0]|length' 
./demo.json

## Displaying the First Document
jq -r 'first(.[])' 
./demo.json

## Displaying the Last Document
jq -r 'last(.[])' 
./demo.json

## Getting the Keys from Root
jq -r '.|keys'
./demo.json

jq -r '.[0]|keys'
./demo.json


## Total elements in each document
jq -r '.[]|length' 
./demo.json

## Get First and Last Name

#Try 1 : Get the first and last names from all documents.
jq -r '.[]|.name.first,.name.last' 
./demo.json

#Try 2 : Convert the multi line output to Array by adding []
jq -r '.[]|[.name.first,.name.last]' 
./demo.json 

# Try 3: This is flattening the output to CSV format
jq -r '.[]|[.name.first,.name.last] | @csv' 
./demo.json

## Adding few more items

jq -r '.[]|[.name.first,.name.last,.email,.phone] | @csv' 
./demo.json 

## Alternate way to display using String Interpolation
## Try 1 :
jq -r '.[]|(.name.first),(.name.last),(.age),(.email),(.phone)' 
./demo.json 

## Try 2:
jq -r '.[]|"\(.name.first),\(.name.last),\(.age),\(.email),\(.phone)"' 
./demo.json


## Now lets try to parse child array
## Try 1
jq -r '.[]|.friends[].name' 
./demo.json

## Try 2 :
jq -r '.[]|[.friends[].name]' 
./demo.json 

## Try 3 : 
jq -r '.[]|[.friends[].name] | @csv' 
./demo.json 

## Denormalizing Parent data with child data

jq -r '.[]|"\(.name.first),\(.name.last),\(.age),\(.email),\(.phone),\(.friends[]|[.id,.name]|@csv)"' 
./demo.json 

## Denormaling it further by adding one more array Temperature

jq -r '.[]|"\(.name.first),\(.name.last),\(.age),\(.email),\(.phone),\(.friends[]|[.id,.name]|@csv),\(.temperature[]|@csv)"' 
./demo.json 

##Adding custom variable

jq -r --arg todayDate "2021-04-24"  '.[]|"\($todayDate),\(.name.first),\(.name.last),\(.age),\(.email),\(.phone),\(.friends[]|[.id,.name]|@csv),\(.temperature[]|@csv)"' 
./demo.json 

## using functions to convert to lower case in jq
jq -r --arg todayDate "2021-04-24"  '.[]|"\($todayDate),\(.name.first|ascii_downcase),\(.name.last|ascii_downcase),\(.age),\(.email),\(.phone),\(.friends[]|[.id,(.name|ascii_downcase)]|@csv),\(.temperature[]|@csv)"' 
./demo.json

## Get eye colors
jq '.[]| [.eyeColor] ' 
./demo.json 

## Filter by eyeColor blue
jq '.[]|select(.eyeColor=="blue")| [.eyeColor,.name.first]' 
./demo.json 

## Applying the same logic on to previous denormalized output.
jq -r --arg todayDate "2021-04-24"  '.[]| select(.eyeColor=="blue")| "\($todayDate),\(.name.first|ascii_downcase),\(.name.last|ascii_downcase),\(.eyeColor),\(.age),\(.email),\(.phone),\(.friends[]|[.id,(.name|ascii_downcase)]|@csv),\(.temperature[]|@csv)"' 
./demo.json

## Separating Data from Filter
## This is a CLI functionality wont work on VSCode Notebook.
jq -r --arg todayDate "2021-04-24" --from-file ./demoparser.jq 
./demo.json