--
-- build/mkman.lua
--
-- Translates bindings from Ion configuration into a listing for
-- manual pages.
--


-- Translations {{{

local translations={}

local function gettext(x)
    local t=translations[x]
    if not t or t=="" then
        return x
    else
        return t
    end
end

local function TR(x, ...)
    return string.format(gettext(x), ...)
end

local function read_translations(pofile)
    local f, err=io.open(pofile)
    if not f then
        error(err)
    end

    local msgid, msgstr, st, en

    for l in f:lines() do
        if string.find(l, "^msgid") then
            if msgid then
                assert(msgstr)
                translations[msgid]=msgstr
                msgstr=nil
            end
            st, en, msgid=string.find(l, '^msgid%s*"(.*)"%s*$')
        elseif string.find(l, "^msgstr") then
            assert(msgid and not msgstr)
            st, en, msgstr=string.find(l, '^msgstr%s*"(.*)"%s*$')
        elseif not (string.find(l, "^%s*#") or string.find(l, "^%s*$")) then
            local st, en, str=string.find(l, '^%s*"(.*)"%s*$')
            assert(msgid or msgstr)
            if not msgstr then
                msgid=msgid..str
            else
                msgstr=msgstr..str
            end
        end
    end

    if msgid then
        assert(msgstr)
        translations[msgid]=msgstr
    end

    f:close()
end

-- }}}


-- File parsing {{{

local function dobindings(f, bindings)
    local p={}
    local dummy = function() end

    p.META="Mod4+"
    p.ALTMETA="Mod4+Shift+"

    p.dopath=dummy
    p.defmenu=dummy
    p.defctxmenu=dummy
    p.menuentry=dummy
    p.submenu=dummy

    p.ioncore={ set=dummy }

    function p.bdoc(text)
        return {action = "doc", text = text}
    end

    function p.submap(kcb_, list)
        if not list then
            return function(lst)
                       return submap(kcb_, lst)
                   end
        end
        return {action = "submap", kcb = kcb_, submap = list}
    end

    local function putcmd(cmd, guard, t)
        t.cmd=cmd
        t.guard=guard
        return t
    end

    function p.kpress(keyspec, cmd, guard)
        return putcmd(cmd, guard, {action = "kpress", kcb = keyspec})
    end

    function p.kpress_wait(keyspec, cmd, guard)
        return putcmd(cmd, guard, {action = "kpress_wait", kcb = keyspec})
    end

    local function mact(act_, kcb_, cmd, guard)
        local st, en, kcb2_, area_=string.find(kcb_, "([^@]*)@(.*)")
        return putcmd(cmd, guard, {
            action = act_,
            kcb = (kcb2_ or kcb_),
            area = area_,
        })
    end

    function p.mclick(buttonspec, cmd, guard)
        return mact("mclick", buttonspec, cmd, guard)
    end

    function p.mdblclick(buttonspec, cmd, guard)
        return mact("mdblclick", buttonspec, cmd, guard)
    end

    function p.mpress(buttonspec, cmd, guard)
        return mact("mpress", buttonspec, cmd, guard)
    end

    function p.mdrag(buttonspec, cmd, guard)
        return mact("mdrag", buttonspec, cmd, guard)
    end

    function ins(t, v)
        if not t.seen then
            t.seen={}
        end

        if (not v.kcb) or v.submap then
            -- Submap rebinds are not presently handled
            table.insert(t, v)
        else
            local id=v.action..":"..v.kcb..":"..(v.area or "")
            local i=t.seen[id]
            if i then
                t[i].invalid=true
            end
            if v.cmd then
                table.insert(t, v)
                t.seen[id]=#t
            else
                -- Unbind only
                t.seen[id]=nil
            end
        end
    end

    function p.defbindings(context, bnd)
        if not bindings[context] then
            bindings[context]={}
        else
            -- Reset documentation
            table.insert(bindings[context], { action = "doc", text = nil })
        end

        for _, v in ipairs(bnd) do
            ins(bindings[context], v)
        end
    end

    local env=setmetatable({}, {
        __index=p,
        __newindex=function(x)
                       error("Setting global "..tostring(x))
                   end,
    })

    local fn, err

    if _ENV then
        fn, err=loadfile(f, nil, env)
    else
        fn, err=loadfile(f)
    end

    if not fn then
        error(err)
    end

    if not _ENV then
        setfenv(fn, env)
    end

    fn()
    return bindings
end

-- }}}


-- Binding output {{{

local function docgroup_bindings(bindings)
    local out={}
    local outi=0

    local function parsetable(t, prefix)
        for _, v in ipairs(t) do
            if not v.invalid then
                if v.kcb then
                    v.kcb=string.gsub(v.kcb, "AnyModifier%+", "")
                end
                if v.action=="doc" then
                    if outi==0 or #out[outi].bindings>0 then
                        outi=outi+1
                    end
                    out[outi]={doc=v.text, bindings={}}
                elseif v.submap then
                    parsetable(v.submap, prefix..v.kcb.." ")
                else
                    assert(out[outi])
                    v.kcb=prefix..v.kcb
                    table.insert(out[outi].bindings, v)
                end
            end
        end
    end

    if outi~=0 and #out[outi].bindings==0 then
        out[outi]=nil
    end

    parsetable(bindings, "")

    return out
end


local function combine_bindings(v)
    local nact={
        ["mpress"]=TR("press"),
        ["mclick"]=TR("click"),
        ["mdrag"]=TR("drag"),
        ["mdblclick"]=TR("double click"),
    }
    local first=true
    local s=""
    for _, b in ipairs(v.bindings) do
        if not first then
            s=s..', '
        end
        first=false
        if b.action=="kpress" or b.action=="kpress_wait" then
            s=s..b.kcb
        else
            if not b.area then
                s=s..TR("%s %s", b.kcb, nact[b.action])
            else
                s=s..TR("%s %s at %s", b.kcb, nact[b.action], b.area)
            end
        end
    end

    return s
end

local function write_bindings_man(db)
    local function write_binding_man(v)
        return '.TP\n.B '..combine_bindings(v)..'\n'..gettext(v.doc or "?")..'\n'
    end

    local s=""

    for _, v in ipairs(db) do
        if #(v.bindings)>0 then
            s=s..write_binding_man(v)
        end
    end

    return s
end

-- }}}

-- Main {{{

local infile
local outfile
local bindings={}
local replaces={}

local function doargs(a)
    local i=1
    while i<=#a do
        if a[i]=='-o' then
            outfile=a[i+1]
            i=i+2
        elseif a[i]=='-i' then
            infile=a[i+1]
            i=i+2
        elseif a[i]=='-D' then
            replaces[a[i+1]]=a[i+2]
            i=i+3
        elseif a[i]=='-po' then
            read_translations(a[i+1])
            i=i+2
        else
            dobindings(a[i], bindings)
            i=i+1
        end
    end
end

doargs(arg)

local f, err=io.open(infile)
if not f then
    error(err)
end

local of, oerr=io.open(outfile, 'w+')
if not of then
    error(oerr)
end

for l in f:lines() do
    l=string.gsub(l, '%s*BINDINGS:([%w%.%-]+)%s*',
                  function(s)
                      if not bindings[s] then
                          --error('No bindings for '..s)
                          return "?"
                      end
                      local db=docgroup_bindings(bindings[s])
                      return write_bindings_man(db)
                  end)

    for pat, rep in pairs(replaces) do
        l=string.gsub(l, pat, rep)
    end

    of:write(l..'\n')
end

-- }}}