Browser

--[[ Midday Navigator Ver. 1.0
     Created by Dimus
     No rights reserved ]]

os.loadAPI('ip')

if not term.isColour() then
    print( "Use advanced computer for view hypertext" )
    return
end

local w,h = term.getSize()
local scrollX, scrollY = 0,0

local tLines = {}
local maxLen=0
local bRunning = true

-- Colours
local highlightColour, textColour, bgColour, tagColour
    bgColour = colours.black
    textColour = colours.white
    highlightColour = colours.yellow
    tagColour = colours.cyan

-- Menus
local bMenu = false
local nMenuItem = 1
local tMenuItems = {"Back","Save","Exit"}
local sTitle = ""
local Site = ""
local Host = ""
local History = {}
local objects={}

local tags={}

local function tagWork(tag)
    local tag_name=tag:match('[/%w_]+')
    if tags[tag_name] then
        local tag_params={}
        for k,v in tag:gmatch('(%w+)=([%w/_]+)') do tag_params[k]=v end
        tags[tag_name](tag_params)
    else
        term.write( '<'..tag..'>' )
    end
end

local function writeHighlighted( sLine )
    local tag,txt
    while string.len(sLine) > 0 do
        -- search tag
        tag,txt=sLine:match("^<(.-)>(.*)")
        while tag do
            sLine=txt
            tagWork( tag )
            tag,txt=sLine:match("^<(.-)>(.*)")
        end
        txt,tag=sLine:match("(.-)(<.->.*)")
        if txt then
            sLine=tag
        else
            txt,sLine=sLine,''
        end
        term.write( txt )
    end
    local lineEnd=term.getCursorPos()
    if lineEnd>maxLen then maxLen=lineEnd end
end

local function redrawText()
    maxLen=0
    objects={}
    term.setTextColour( textColour )
    for y=1,h-2 do
        term.setCursorPos( 1 - scrollX, y + 2 )
        term.clearLine()

        local sLine = tLines[ y + scrollY ]
        if sLine ~= nil then
            writeHighlighted( sLine )
        end
    end
--    local x,y = 1 - scrollX, 3
--  term.setCursorPos( x, y )
--  term.clearLine()
--  local sLine = tLines[ y + scrollY ]
--  if sLine ~= nil then
--      writeHighlighted( sLine )
--  end
--    x,y=term.getCursorPos

end

local function redrawMenu()
    term.setBackgroundColour( colours.blue )
    term.setCursorPos( 1, 1 )
    term.clearLine()

    local sLeft
    local nLeftColour, nLeftHighlight1, nLeftHighlight2
    if bMenu then
        local sMenu = ""
        for n,sItem in ipairs( tMenuItems ) do
            if n == nMenuItem then
                nLeftHighlight1 = sMenu:len() + 1
                nLeftHighlight2 = sMenu:len() + sItem:len() + 2
            end
            sMenu = sMenu.." "..sItem.." "
        end
        sLeft = sMenu
        nLeftColour = textColour
    else
        sLeft = sTitle
        if #sLeft>0 then sLeft=sLeft.." - " end
        sLeft = sLeft.."Midday Navigator"
        nLeftColour = highlightColour
    end

    if sLeft then
        term.setCursorPos( 1, 1 )
        term.setTextColour( nLeftColour )
        term.write(sLeft)
        if nLeftHighlight1 then
            term.setTextColour( highlightColour )
            term.setCursorPos( nLeftHighlight1, 1 )
            term.write( "[" )
            term.setCursorPos( nLeftHighlight2, 1 )
            term.write( "]" )
        end
    end

    term.setCursorPos( w-2 , 1 )
    term.write( "< " )
    term.setBackgroundColour( colours.red )
    term.write( "X" )

    term.setBackgroundColour( colours.white )
    term.setTextColour( colours.black )
    term.setCursorPos( 2, 2 )
    term.clearLine()
    term.write( Host..'/'..Site )

    term.setTextColour( textColour )
    term.setBackgroundColour( bgColour )
end

local function load(_sPath)
    if _sPath=='' or _sPath ==nil then redrawMenu() return end
    tLines = {}
    scrollX, scrollY = 0,0
    Host,Site=_sPath:match('(.-)/(.*)')
    if not Host then Host=_sPath Site='' end
    if Host=='' then
        local file = io.open( Site, "r" )
        if file then
          local sLine = file:read()
          while sLine do
            table.insert( tLines, sLine )
            sLine = file:read()
          end
          file:close()
        else
            table.insert( tLines, 'Can not open file "'..Site..'"' )
        end
    else
        if ip.open() then
          if ip.getIP() then
            ip.send(Host,Site)
            print(Host,' <',Site,'>')
            local addr,sLines
--            repeat
              sLines,addr=ip.receive(3)
              if not addr then sLines='No ansver from server' end
--            until addr==Host
            sLines=sLines..'\n'
            for sLine in sLines:gmatch('(.-)\n') do
              table.insert( tLines, sLine )
            end
          else
            table.insert( tLines, 'Can not connect to Craftnet' )
          end
        else
            table.insert( tLines, 'Can not open modem' )
        end
    end

    if #tLines == 0 then
        table.insert( tLines, "" )
    end
    if History[#History]~=_sPath then table.insert( History, _sPath ) end
    term.setBackgroundColour( bgColour )
    term.clear()
    term.setCursorBlink( false )
    redrawText()
    redrawMenu()
end

local tMenuFuncs = {
    Back=function()
        if #History>1 then
            History[#History]=nil
            load(History[#History])
        end
    end,
    Save=function()
    end,
    Exit=function()
        bRunning = false
    end
}

local function doMenuItem( _n )
    tMenuFuncs[tMenuItems[_n]]()
    bMenu = false
end

-- Tags
tags['font']=function(arg)
    if arg.color and colours[arg.color] then
      term.setTextColour( colours[arg.color] )
    end
    if arg.bgcolor and colours[arg.bgcolor] then
      term.setBackgroundColour(colours[arg.bgcolor])
    end
end
tags['/font']=function()
    term.setTextColour( textColour )
    term.setBackgroundColour( bgColour )
end

local function line_check(obj,x,y)
    if y>=obj.y1 and y<=obj.y2 then
        if x>=obj.x1 or y>obj.y1 then
            if x<=obj.x2 or y<obj.y2 then
                obj:work()
                return true
            end
        end
    end
    return false
end
local function href_work(obj)
  load(obj.href)
end
local function ref_work(obj)
  load(Host..'/'..obj.ref)
end
tags['a']=function(arg)
    if arg.href then
      term.setTextColour( tagColour )
      local href={check=line_check, work=href_work}
      href.x1, href.y1 = term.getCursorPos()
      href.href = arg.href
      table.insert(objects, href)
    end
    if arg.ref then
      term.setTextColour( tagColour )
      local ref={check=line_check, work=ref_work}
      ref.x1, ref.y1 = term.getCursorPos()
      ref.ref = arg.ref
      table.insert(objects, ref)
    end
end
tags['/a']=function()
    term.setTextColour( textColour )
    local href=objects[#objects]
    if href and not href.x2 then
      href.x2, href.y2 = term.getCursorPos()
      href.x2=href.x2 - 1
    end
end

--Key events
local eventKey={}
local eventMenu={}
eventKey[keys.up]=function()
-- Move screen up
    if scrollY > 0 then scrollY = scrollY - 1 end
end
eventKey[keys.down]=function()
-- Move screen down
    if scrollY < #tLines - (h-1) then   scrollY = scrollY + 1 end
end
eventKey[keys.pageUp]=function()
-- Move screen up
    scrollY = scrollY - h - 1
    if scrollY<0 then scrollY=0 end
end
eventKey[keys.pageUp]=function()
-- Move screen up
    scrollY = scrollY - h - 1
    if scrollY<0 then scrollY=0 end
end
eventKey[keys.pageUp]=function()
-- Move screen up
    scrollY = scrollY - h - 1
    if scrollY<0 then scrollY=0 end
end
eventKey[keys.pageDown]=function()
-- Move screen up
    scrollY = scrollY + h - 2
    if scrollY>#tLines-h+1 then scrollY=#tLines-h+1 end
end
eventKey[keys.home]=function()
-- Move cursor to the beginning
    scrollX = 0
end
eventKey[keys["end"]]=function()
-- Move cursor to the end
    if maxLen>w then scrollX = scrollX+maxLen-w end
end
eventKey[keys.left]=function()
-- Move screen left
    if scrollX > 0 then scrollX = scrollX - 1 end
end
eventKey[keys.right]=function()
-- Move screen right
    if maxLen > w then scrollX = scrollX + 1 end
end
eventKey[keys.leftCtrl]=function()
-- Menu toggle
    bMenu = not bMenu
    redrawMenu()
end
eventKey[keys.rightCtrl]=eventKey[keys.leftCtrl]

eventMenu[keys.left]=function()
-- Move menu left
    nMenuItem = nMenuItem - 1
    if nMenuItem < 1 then nMenuItem = #tMenuItems end
end
eventMenu[keys.right]=function()
-- Move menu right
    nMenuItem = nMenuItem + 1
    if nMenuItem > #tMenuItems then nMenuItem = 1 end
end
eventMenu[keys.enter]=function()
-- Menu selection
    doMenuItem( nMenuItem )
end
eventMenu[keys.leftCtrl]=function()
-- Menu toggle
    bMenu = not bMenu
end
eventMenu[keys.rightCtrl]=eventMenu[keys.leftCtrl]

-- Actual program functionality begins
-- Get file to view
local tArgs = { ... }
if #tArgs > 0 then
    local sPath = shell.resolve( tArgs[1] )
    load(sPath)
end

term.setBackgroundColour( bgColour )
term.clear()
term.setCursorBlink( false )

redrawText()
redrawMenu()
-- Handle input
while bRunning do
    local sEvent, param, param2, param3 = os.pullEvent()
    if sEvent == "key" then
      if bMenu then
        if eventMenu[param] then eventMenu[param]() redrawMenu() end
      else
        if eventKey[param] then  eventKey[param]() redrawText() end
      end

    elseif sEvent == "mouse_click" then
        if not bMenu then
            if param == 1 then
                -- Left click
                local cx,cy = param2, param3
                if cy == 1 then
                    if cx==w then tMenuFuncs.Exit() end
                    if cx==w-2 then tMenuFuncs.Back() end
                elseif cy==2 then
                    term.setBackgroundColour( colours.white )
                    term.setTextColour( colours.black )
                    term.setCursorPos( 2, 2 )
                    term.clearLine()
                    load(read(nil, History))
                else
                    for i=1,#objects do
                      if objects[i].check
                      and objects[i].check(objects[i],cx,cy) then break end
                    end
                end
            end
        end

    elseif sEvent == "mouse_scroll" then
        if not bMenu then
            if param == -1 then
                -- Scroll up
                if scrollY > 0 then
                    scrollY = scrollY - 1
                    redrawText()
                end

            elseif param == 1 then
                -- Scroll down
                local nMaxScroll = #tLines - (h-1)
                if scrollY < nMaxScroll then
                    scrollY = scrollY + 1
                    redrawText()
                end

            end
        end
    end
end

-- Cleanup
term.clear()
term.setCursorBlink( false )
term.setCursorPos( 1, 1 )