Doc

-- The http API is nil when it's not enabled.
if not http then
    printError "The HTTP API must be enabled!"
    return
end

local argv = {...}
local argc = #argv

local scrWidth,scrHeight = term.getSize()

-- Used for code examples. Taken straight from rom/programs/edit.
local keywords = {
    ["and"] = true,
    ["break"] = true,
    ["do"] = true,
    ["else"] = true,
    ["elseif"] = true,
    ["end"] = true,
    ["false"] = true,
    ["for"] = true,
    ["function"] = true,
    ["if"] = true,
    ["in"] = true,
    ["local"] = true,
    ["nil"] = true,
    ["not"] = true,
    ["or"] = true,
    ["repeat"] = true,
    ["return"] = true,
    ["then"] = true,
    ["true"] = true,
    ["until"] = true,
    ["while"] = true
}

CC_WIKI_API = "http://computercraft.info/wiki/api.php"

-- If the argument count is less than 2, too few arguments were supplied.
if argc < 2 then
    printError "Usage: doc <api/func> <name>"
    return
end

-- Capitalise first letter.
argv[2]:gsub("^%l", string.upper)

local function trimString(str)
    return str:gsub("^%s*(.-)", "%1")
end

local function writeFormatted(str)
    for word in str:gmatch("%S+") do
        local col, txt = word:gmatch("\\\\(%d+):(.+)//")()

        if col ~= nil then
            if term.isColour() then
                term.setTextColour(tonumber(col))
            end
            txt = txt:gsub("\\\\_//", " ")
            word = txt
        end

        if word == "\\\\nl//" then
            print()
        else
            write(word .. " ")
        end
        term.setTextColour(colours.white)
    end
end

local function writeToWnd(wnd, str)
    local oldTerm = nil

    if term.current then
        oldTerm = term.redirect(wnd)
    else
        term.redirect(wnd)
    end

    writeFormatted(str)

    if term.restore then
        term.restore()
    else
        term.redirect(oldTerm)
    end
end

local function setDefaultColours(buf)
    buf = buf or term
    buf.setBackgroundColour(colours.black)
    buf.setTextColour(colours.white)
end

local function setCaptionColours(buf)
    buf = buf or term
    buf.setBackgroundColour(colours.white)
    buf.setTextColour(colours.black)
end

local function makePatternFriendly(str)
    local result = str:gsub("%%", "%%%")
    result = result:gsub("%(", "%%(")
    result = result:gsub("%)", "%%)")
    result = result:gsub("%[", "%%[")
    result = result:gsub("%?", "%%?")
    result = result:gsub("%*", "%%*")
    result = result:gsub("%+", "%%+")
    result = result:gsub("%-", "%%-")
    result = result:gsub("%^", "%%^")
    result = result:gsub("%.", "%%.")
    result = result:gsub("%$", "%%$")
    return result
end

local function parseCode(code)
    local result = code
    result = result:gsub("\n", " \\\\nl// ")
    result = result:gsub("\r", "")
    result = result:gsub("<br/?>", " \\\\nl// ")

    for k,v in pairs(keywords) do
        result = result:gsub("%s-(" .. k .. ")%s+", "\\\\" .. colours.yellow .. ":%1//")
    end

    return result
end

local function parseExamples(exText)
    local result = ""
    local isFirst = true

--  error(makePatternFriendly(exText))

    for example in exText:gmatch("{{(.-)}}") do
        local code = example:gmatch("|code=(.+)%s|")()

        if code ~= nil then
            if not isFirst then
                result = result .. "\\\\"
            end

            result = result .. parseCode(code)
            isFirst = false
        end
    end

    return result
end

local function convertMarkup(mrkup, isExample)
    if isExample == nil then isExample = false end

    -- Replace the HTML codes with their actual symbols.
    local result = mrkup:gsub("&quot;", "\"")
    result = result:gsub("&gt;", ">")
    result = result:gsub("&lt;", "<")
    result = result:gsub("&amp;", "&")

    -- Replace &#[ascii code]; with the proper character (e.g: '&#37;' -> '%').
    for word, byte in result:gmatch("(&#(%d+);)") do
        local corrected = string.char(byte)
        result = result:gsub(word, makePatternFriendly(corrected))
    end

    if isExample then
        result = parseExamples(result)
    end

    -- Remove HTML tags.
    result = result:gsub("</?.-/?>", "")

    -- Replace type references with highlighted text.
    result = result:gsub("{{.-|(.-)}}", "\\\\" .. colours.lime .. ":%1//")

    -- Replace links with highlighted text.
    result = result:gsub("%[%[.-|(.-)]]", "\\\\" .. colours.blue .. ":%1//")
    result = result:gsub("%[%[(.-)]]", "\\\\" .. colours.blue .. ":%1//")

    -- Replace double quotes with single quotes (''text'' -> 'text').
    result = result:gsub("''(.-)''", "'%1'")

    -- Replace spaces in colour highlighting with "\\_//".
    for word in result:gmatch("\\\\%d+:.-//") do
        local newword = word:gsub("%s", "\\\\_//")
        result = result:gsub(makePatternFriendly(word), makePatternFriendly(newword))
    end

    result = trimString(result)
    return result
end

local function renderGUI(elements, activeElement, wnd)
    wnd.setBackgroundColour(colours.black)
    wnd.clear()
    wnd.redraw()

    term.setTextColor(colours.white)
    term.setCursorPos(1, scrHeight)
    term.write("Arrow keys to change category; Enter to quit")

    term.setCursorPos(1, 2)
    term.setBackgroundColour(colours.black)
    term.clearLine()

    term.setCursorPos(1, 3)
    term.setTextColor(colours.white)

    for i=1,scrWidth do
        term.write("-")
    end

    local nextTabPos = 1

    for i,v in ipairs(elements) do
        if v.isTitle ~= nil and v.isTitle then
            local txt = v.body
            term.setCursorPos(scrWidth / 2 - #txt / 2, 1)
            term.setBackgroundColour(colours.white)
            term.setTextColour(colours.black)
            term.write(txt)
        else
            if v.id == activeElement then
                local cap = v.caption
                term.setCursorPos(nextTabPos, 2)
                term.setBackgroundColour(colours.white)
                term.setTextColour(colours.black)
                term.write(cap)
                nextTabPos = nextTabPos + #cap + 1

                wnd.setCursorPos(1, 1)

                if v.body ~= "" then
                    writeToWnd(wnd, v.body)
                else
                    writeToWnd(wnd, "\\\\" .. colours.red .. ":N/A//")
                end
            else
                local cap = v.caption
                term.setCursorPos(nextTabPos, 2)
                term.setBackgroundColour(colours.black)
                term.setTextColour(colours.white)
                term.write(cap)
                nextTabPos = nextTabPos + #cap + 1
            end
        end
    end
end

local function enterGUI(elements)
    term.setBackgroundColour(colours.black)
    term.clear()
    term.setCursorPos(1, 1)

    local guiActive = true
    local activeElement = 1

    local trm = nil

    if term.current then
        trm = term.current()
    else
        trm = term
    end

    local wnd = window.create(trm, 1, 4, scrWidth, scrHeight - 5)
    wnd.setVisible(true)
    renderGUI(elements, activeElement, wnd)

    while guiActive do
        local e,p1,p2,p3 = os.pullEvent()
        local doDraw = true

        if e == "key" then
            if p1 == keys.enter then
                wnd.setVisible(false)
                term.setBackgroundColour(colours.black)
                term.clear()
                term.setCursorPos(1, 1)

                guiActive = false
                doDraw = false
            elseif p1 == keys.up or p1 == keys.left then
                activeElement = activeElement - 1
                if activeElement < 1 then activeElement = 1 end
            elseif p1 == keys.down or p1 == keys.right then
                activeElement = activeElement + 1
                if activeElement > #elements - 1 then activeElement = #elements - 1 end
            end
        end

        if doDraw then
            renderGUI(elements, activeElement, wnd)
        end
    end
end

function printWikiInfo(xml)
    -- Get the content from the first found 'rev' tag.
    local content = xml:gmatch("<rev .->(.-)</rev>")()

    if content == nil then
        printError "No such function."
        return
    end

    local name = content:gmatch("|name=(.-)%s|")()
    name = convertMarkup(name or "")

    local description = content:gmatch("|desc=(.-)%s|")()
    description = convertMarkup(description or "")

    local arguments = content:gmatch("|args=(.-)%s|")()
    arguments = convertMarkup(arguments or "")

    local returns = content:gmatch("|returns=(.-)%s|")()
    returns = convertMarkup(returns or "")

    local examples = content:gmatch("|examples=(.-}})")()
    examples = convertMarkup(examples or "", true)

    local elems = {}
    local lastID = 0
    local nextID = 1

    if name ~= "" then
        elems[#elems + 1] = {
            id = 0,
            isTitle = true,
            caption = nil,
            body = name
        }
    end

    if description ~= "" then
        elems[#elems + 1] = {
            id = nextID,
            caption = "Description",
            body = description
        }

        nextID = nextID + 1
    end

    if arguments ~= "" then
        elems[#elems + 1] = {
            id = nextID,
            caption = "Arguments",
            body = arguments
        }

        nextID = nextID + 1
    end

    if returns ~= "" then
        elems[#elems + 1] = {
            id = nextID,
            caption = "Returns",
            body = returns
        }

        nextID = nextID + 1
    end

    if examples ~= "" then
        elems[#elems + 1] = {
            id = nextID,
            caption = "Examples",
            body = examples
        }

        nextID = nextID + 1
    end

    enterGUI(elems)
end

setDefaultColours()
term.clear()
term.setCursorPos(1, 1)

print("...")

term.setCursorPos(1, 1)

if argv[1] == "func" then
    local headers = {
        ["User-Agent"] = "Doc/1.1"
    }

    local req = http.get(CC_WIKI_API .. "?format=xml&action=query&titles=" .. textutils.urlEncode(argv[2]) .. "&prop=revisions&rvprop=content", headers)

    if req == nil then
        printError "Failed to connect to the CC Wiki!"
        return
    end

    -- If the response code is 404, the page couldn't be found.
    if req.getResponseCode() == 404 then
        printError("There is no documentation available for \"" .. argv[2] .. "\".")
        return
    end

    local contents = req.readAll()
    req.close()
    printWikiInfo(contents)
elseif argv[1] == "api" then
    setCaptionColours()
    print("Functions in \"" .. argv[2] .. "\":")

    if _G[argv[2]] == nil then
        setDefaultColours()
        printError "No such API."
        return
    end

    local functions = {}

    for k,v in pairs(_G[argv[2]]) do
        if type(v) == "function" then
            functions[#functions + 1] = tostring(k)
        end
    end

    setDefaultColours()
    textutils.pagedTabulate(functions)
elseif argv[1] == "print" then
    local str = ""

    for i=2,argc do
        str = str .. argv[i] .. " "
    end

    str = decodeMarkup(str)
    writeFormatted(str)
    print()
end