Shiny app for using and displaying text data from csv files

Looking for a shiny app and corresponding R code to achieve the following:

1. Receive directory from user into text box (or allow to click and find)
2. Get all files with CSV termination and start as "result".
A sample of a file that will be picked up: 
results20200731 zar-daily rr 0.01.csv
results20190213 eurmxn-weekly rr 0.0025.csv

3. Create data.frame with columns Date , ccy, frq, filename where output would look like:
date    ccy    frq    filename
07/31/20    zar    daily    results20200731 zar-daily rr 0.01.csv
02/13/19    eurmxn    weekly    results20190213 eurmxn-weekly rr 0.0025.csv
(notice date column is in Date format)

4.Provide user option to load information for a certain currency + Date + freq combo via dropdown and load that information into data frame.
Inside each csv information in format string1&string2&string3 example inside of file:
string1.1&string2.1&string3.1
string1.1&string2.1&string3.2
string1.1&string2.2&string3.1
string1.1&string2.2&string3.2
string2.1&string2.1&string3.1
string2.1&string2.1&string3.2
string2.1&string2.2&string3.1
string2.1&string2.2&string3.2

so data frame should look like:

Date    ccy    freq    cond1    cond2    cond3
07/31/20    zar    daily    string1.1    string2.1    string3.1
07/31/20    zar    daily    string1.1    string2.1    string3.2
07/31/20    zar    daily    string1.1    string2.2    string3.1
07/31/20    zar    daily    string1.1    string2.2    string3.2
07/31/20    zar    daily    string1.2    string2.1    string3.1
07/31/20    zar    daily    string1.2    string2.1    string3.2
07/31/20    zar    daily    string1.2    string2.2    string3.1
07/31/20    zar    daily    string1.2    string2.2    string3.2


5. Allow user to create element tree view (that looks like window file explorer style) by cond1, cond2, or cond3  (hierarchy 1, hierarchy 2)
for example: if hierarchy 1 selected is cond1 and hierarchy 2 is cond2 then user would see tree as:
string1.1->
    string.2.1->
        string.3.1
        string 3.2
    string.2.2->
        string.3.1
        string 3.2
string1.2->
    string.2.1->
        string.3.1
        string 3.2
    string.2.2->
        string.3.1
        string 3.2

for example: if hierarchy 1 selected is cond3 and hierarchy 2 is cond1 then user would see tree as:

string3.1->
    string.1.1->
        string.2.1
        string 2.2
    string.1.2->
        string.2.1
        string 2.2
string3.2->
    string.1.1->
        string.2.1
        string 2.2
    string.1.2->
        string.2.1
        string 2.2



6.  Construct text output based on elements from tree selected by user.


Example:  if user selects as follows
string1.1->
    string.2.1->
        string.3.1  XSELECTED
        string 3.2
    string.2.2->
        string.3.1
        string 3.2 XSELECTED
string1.2->
    string.2.1->
        string.3.1
        string 3.2
    string.2.2->
        string.3.1 XSELECTED
        string 3.2 XSELECTED

Output text would be: 
c("string1.1&string2.1&string3.1",
"string1.1&string2.2&string3.2",
"string1.2&string2.2&string3.1",
"string1.2&string2.2&string3.1")

Output text would be displayed in textbox

7. Allow user to copy output text to clipboard and also to save it to a csv file