#!/usr/local/bin/lua
----------------------------------------------------------------
--
-- htmpp.lua
--
-- Copyright (C) 2003 Ian King
-- All Rights Reserved.
--
-- Redistribution and use in source and binary forms, with or without
-- modification, are permitted provided that this entire copyright notice
-- is duplicated in all such copies.
--
-- This software is provided "as is" and without any expressed or implied
-- warranties, including, without limitation, the implied warranties of
-- merchantibility and fitness for any particular purpose.
-- 
----------------------------------------------------------------

-- uses it's own tag syntax
--  <$insert "filename.html">  inserts filename.html into this file
--  <$set varname sometext>    sets a variable
--  <$varname>                 inserts value of variable
--  <$datetime "format">       inserts a date/time string.  format same as os.date("format") i.e. same as strftime()

------------------------------------------------
--debug_htmpp = 1 -- comment out for 'release' version

Vars = {}
Vars.Store = {}
Vars.Store.htmpp_name    = "htmpp"
Vars.Store.htmpp_version = "0.1"
Vars.Store.htmpp_author  = "Ian King"

function Vars:AddVar(name, value)
    self.Store[name] = value
end

function Vars:GetValue(name)

    local v = self.Store[name]
    assert(v, "Variable '"..name.."' not found")
    
    return v
end

-- debug_htmpp function
function Vars:Dump()
    table.foreach(self.Store, print)
end

------------------------------------------------

function EvaluateTag(str, outfile)
    
    if str then
        local f, l, s1, s2
        
        if debug_htmpp then print("EvaluateTag '"..str.."'") end

        f, l, s1, s2 = string.find(str, "^set%s+([_%w]+)%s*([^\>]*)")
        if f then
            Vars:AddVar(s1, s2)
            return
        end
        
        f, l, s1 = string.find(str, "^insert%s+\"([^\"]*)\"%s*")
        if f then
            ProcessFile(s1, outfile)
            return
        end
        
        f, l, s1 = string.find(str, "^datetime%s+\"([^\"]*)\"%s*")
        if f then
            assert(outfile:write(os.date(s1)))
            return
        end

        f, l, s1 = string.find(str, "^([_%w]+)%s*")
        if f then
            assert(outfile:write(Vars:GetValue(s1)))
            return
        end

        assert("Unknown htmpp syntax [["..str.."]]")
    end
end

------------------------------------------------

function ParseLine(str, outfile)

    local f, l, s1, s2

    if str and str ~= "" then
        
        if debug_htmpp then
            print("ParseLine '"..str.."'")
        end
        
        f, l, s1, s2 = string.find(str, "\<\$([^\>]*)\>(.*)")

        if debug_htmpp then
            print(f, l, s1, s2)
        end

        if f then
            if f ~= 1 then
                assert(outfile:write(string.sub(str, 1, f-1)))
            end
            
            EvaluateTag(s1, outfile)
            ParseLine(s2, outfile)
        else
            assert(outfile:write(str))
        end
    end
end    

------------------------------------------------

function ProcessFile(filename, outfile)
    
    -- open file
    local infile, ferr = io.open(filename, "r")
    assert(infile, ferr)

    -- process file
    local line
    for line in infile:lines() do
        ParseLine(line, outfile)
        assert(outfile:write("\n"))
    end
    
    -- close file
    infile:close()
end

------------------------------------------------

outfile, ferr = io.open(arg[2], "w+")
assert(outfile, ferr)
ProcessFile(arg[1], outfile)
outfile:close()
if debug_htmpp then
    print("--- Final variable values ---")
    Vars:Dump()
end

-- The End --
------------------------------------------------