--Vi Inspired Textual Editor === VITE
-- Version alpha 0.02
filename="./dummy.txt"
VER="v0.02" 
nc=require("nocurses")


function at(s,p)
    return string.sub(s,p,p)
end

----------------------------end small funcs
function start()
    nc.setunderline(true)
    print("VITE === Vi Inspired Textual Editor === "..VER)    
    
    nc.setunderline(false)
    currline=-1
    currfile=-1
    lines_tbl={}
    cmd()
    --after closing
    if currfile ~= -1 then
        print("closing vite...bye")
        currfile:close()
    end
end
-- list of Commands 
-- ----------------
-- * = newfile
-- > = appendtext
-- : = commands
--
function cmd()
    while inp~=":q" do
        -- main loop
     if currline== -1 then
            print("No file opened")
     elseif currline~=-1 then
            print(currline..":")
     end
     nc.setfontcolor("YELLOW")
     inp = io.input():read("*l")
     nc.setfontcolor("WHITE")
     -- all commands start with a symbol 
        if at(inp,1)=="*" and string.len(inp)<=1 then
           print("You must enter a valid filename...")
        elseif at(inp,1)=="*" and string.len(inp)>1 then
            newfn=string.sub(inp,2)
            new_file(newfn)
            print("New File:"..newfn.."\n")
            currline=1
        elseif at(inp,1) == ">" and string.len(inp)==1  then
            print("line [#"..currline.."]:")
        -- if inp has > symbol, then its a literal line to write to file 
        elseif at(inp,1) == ">" and string.len(inp)>1 then  
            table.insert(lines_tbl,currline,string.sub(inp,2))
            currline=currline+1
        elseif at(inp,1) == ":" and at(inp,2)=="l" and string.len(inp)>2 then
              -- TODO MAKE LOAD FUNC TODO
        elseif at(inp,1) == ":" and at(inp,2)=="w" then
           write_file() 
        elseif at(inp,1) == "=" and string.len(inp)==1 then
            display_text()
        elseif string.match(inp,"[%d*][%>][%g*]") and string.len(inp)>2 then
            add_line(lpos,str)
        elseif at(inp,1)=="x" and at(inp,2)=="!" then
            break
        else
            nc.setfontcolor("RED")
            print("Unknown Command!")
            nc.setfontcolor("WHITE")
        -- end of command def ==========
        end
        
    end
end



function add_line(lpos,str)
    local str,lpos
    if currfile~=-1 then
        table.insert(lines_tbl,lpos,str)
    else
        print("No file Open!")
    end
end

function write_file() -- flush data to the file":w" 
    if currfile~=-1 then
        currfile:write(table.concat(lines_tbl,"\n").."\n")
        print("Flushed buffer unto "..newfn) 
        -- TODO Show filesize
    else
        print("No file to write to !")
    end
end

function new_file(fn) --also load
    if currfile==-1 then 
        currfile = io.open(fn,"w+")
    elseif currfile~=-1 then
        currfile:close()
        -- XXX Make it ask for confirm
        -- XXX make it display whats going on
    currfile = io.open(fn,"w+")
    end
end

function display_file()
    currfile:seek("set")
    local lnum = 1
    for line in currfile:lines() do
        nc.gotoxy(1,lnum)
        print(lnum..":"..line)
        lnum=lnum+1
    end
    print("=================================\n\n")
end
function display_text() -- prints lines_tbl
    currfile:seek("set")
    local line
    nc.clrscr()
    nc.setfontcolor("CYAN")
    for k,ln in pairs(lines_tbl) do
        nc.gotoxy(1,k)
        print(k..":"..ln)
    end
    print("=================================\n\n")
    nc.setfontcolor("WHITE")

end

start()