--!A cross-platform build utility based on Lua
--
-- Licensed under the Apache License, Version 2.0 (the "License");
-- you may not use this file except in compliance with the License.
-- You may obtain a copy of the License at
--
--     http://www.apache.org/licenses/LICENSE-2.0
--
-- Unless required by applicable law or agreed to in writing, software
-- distributed under the License is distributed on an "AS IS" BASIS,
-- WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-- See the License for the specific language governing permissions and
-- limitations under the License.
--
-- Copyright (C) 2015-present, Xmake Open Source Community.
--
-- @author      ruki
-- @file        verilator.lua
--

-- imports
import("utils.progress")
import("core.base.hashset")
import("core.project.depend")
import("private.action.build.object", {alias = "build_objectfiles"})

-- parse sourcefiles from cmakefile
function _get_sourcefiles_from_cmake(target, cmakefile)
    local global_classes = {}
    local classefiles_slow = {}
    local classefiles_fast = {}
    local supportfiles_slow = {}
    local supportfiles_fast = {}
    local targetname = target:name()
    local verilator_root = assert(target:data("verilator.root"), "no verilator_root!")
    io.gsub(cmakefile, "set%((%S-) (.-)%)", function (key, values)
        if key == targetname .. "_GLOBAL" then
            -- get global class source files
            -- set(hello_GLOBAL "${VERILATOR_ROOT}/include/verilated.cpp" "${VERILATOR_ROOT}/include/verilated_threads.cpp")
            for classfile in values:gmatch("\"(.-)\"") do
                classfile = classfile:gsub("%${VERILATOR_ROOT}", verilator_root)
                if os.isfile(classfile) then
                    table.insert(global_classes, classfile)
                end
            end
        elseif key == targetname .. "_CLASSES_SLOW" then
            for classfile in values:gmatch("\"(.-)\"") do
                table.insert(classefiles_slow, classfile)
            end
        elseif key == targetname .. "_CLASSES_FAST" then
            for classfile in values:gmatch("\"(.-)\"") do
                table.insert(classefiles_fast, classfile)
            end
        elseif key == targetname .. "_SUPPORT_SLOW" then
            for classfile in values:gmatch("\"(.-)\"") do
                table.insert(supportfiles_slow, classfile)
            end
        elseif key == targetname .. "_SUPPORT_FAST" then
            for classfile in values:gmatch("\"(.-)\"") do
                table.insert(supportfiles_fast, classfile)
            end
        end
    end)

    -- get compiled source files
    local sourcefiles = table.join(global_classes, classefiles_slow, classefiles_fast, supportfiles_slow, supportfiles_fast)
    return sourcefiles
end

-- get languages
--
-- Select the Verilog language generation to support in the compiler.
-- This selects between v1364-1995, v1364-2001, v1364-2005, v1800-2005, v1800-2009, v1800-2012.
--
function _get_lanuage_flags(target)
    local language_v
    local languages = target:get("languages")
    if languages then
        for _, language in ipairs(languages) do
            if language:startswith("v") then
                language_v = language
                break
            end
        end
    end
    if language_v then
        local maps = {
            -- Verilog
            ["v1364-1995"] = "+1364-1995ext+v",
            ["v1364-2001"] = "+1364-2001ext+v",
            ["v1364-2005"] = "+1364-2005ext+v",
            -- SystemVerilog
            ["v1800-2005"] = "+1800-2005ext+v",
            ["v1800-2009"] = "+1800-2009ext+v",
            ["v1800-2012"] = "+1800-2012ext+v",
            ["v1800-2017"] = "+1800-2017ext+v",
        }
        local flag = maps[language_v]
        if flag then
            return flag
        else
            assert("unknown language(%s) for verilator!", language_v)
        end
    end
end

function config(target)
    local toolchain = assert(target:toolchain("verilator"), 'we need to set_toolchains("verilator") in target("%s")', target:name())
    local verilator = assert(toolchain:config("verilator"), "verilator not found!")
    local autogendir = path.join(target:autogendir(), "rules", "verilator")
    local tmpdir = os.tmpfile() .. ".dir"
    local cmakefile = path.join(tmpdir, "test.cmake")
    local sourcefile = path.join(tmpdir, "main.v")
    local argv = {"--cc", "--make", "cmake", "--prefix", "test", "--Mdir", tmpdir, "main.v"}
    local flags = target:values("verilator.flags")
    local switches_flags = hashset.of( "sc", "coverage", "timing", "trace", "trace-fst", "threads")
    if flags then
        for idx, flag in ipairs(flags) do
            if flag:startswith("--") and switches_flags:has(flag:sub(3)) then
                table.insert(argv, flag)
                if flag:startswith("--threads") then
                    table.insert(argv, flags[idx + 1])
                end
            end
        end
    end
    io.writefile(sourcefile, [[
module hello;
initial begin
$display("hello world!");
$finish ;
end
endmodule]])
    os.mkdir(tmpdir)
    -- we just pass relative sourcefile path to solve this issue on windows.
    -- @see https://github.com/verilator/verilator/issues/3873
    os.runv(verilator, argv, {curdir = tmpdir, envs = toolchain:runenvs()})

    -- parse some configurations from cmakefile
    local verilator_root
    local switches = {}
    local targetname = target:name()
    io.gsub(cmakefile, "set%((%S-) (.-)%)", function (key, values)
        if key == "VERILATOR_ROOT" then
            verilator_root = values:match("\"(.-)\" CACHE PATH")
            if not verilator_root then
                verilator_root = values:match("(.-) CACHE PATH")
            end
        elseif key == "test_SC" then
            -- SystemC output mode?  0/1 (from --sc)
            switches.SC = values:trim()
        elseif key == "test_COVERAGE" then
            -- Coverage output mode?  0/1 (from --coverage)
            switches.COVERAGE = values:trim()
        elseif key == "test_TIMING" then
            -- Timing mode?  0/1 (from --timing)
            switches.TIMING = values:trim()
        elseif key == "test_THREADS" then
            -- Threaded output mode?  1/N threads (from --threads)
            switches.THREADS = values:trim()
        elseif key == "test_TRACE_VCD" then
            -- VCD Tracing output mode?  0/1 (from --trace)
            switches.TRACE_VCD = values:trim()
        elseif key == "test_TRACE_FST" then
            -- FST Tracing output mode? 0/1 (from --trace-fst)
            switches.TRACE_FST = values:trim()
        end

    end)
    assert(verilator_root, "the verilator root directory not found!")
    target:data_set("verilator.root", verilator_root)

    -- add includedirs
    if not os.isfile(autogendir) then
        os.mkdir(autogendir)
    end
    target:add("includedirs", autogendir, {public = true})
    target:add("includedirs", path.join(verilator_root, "include"), {public = true})
    target:add("includedirs", path.join(verilator_root, "include", "vltstd"), {public = true})

    -- set languages
    local languages = target:get("languages")
    local cxxlang = false
    for _, lang in ipairs(languages) do
        if lang:startswith("xx") or lang:startswith("++") then
            cxxlang = true
            break
        end
    end
    if not cxxlang then
        target:add("languages", "c++20", {public = true})
    end

    -- add definitions for switches
    for k, v in table.orderpairs(switches) do
        target:add("defines", "VM_" .. k .. "=" .. v, {public = true})
    end

    -- add syslinks
    if target:is_plat("linux", "macosx") and switches.THREADS == "1" then
        target:add("syslinks", "pthread")
    end
    if target:is_plat("linux", "macosx") and switches.TRACE_FST == "1" then
        target:add("syslinks", "z")
    end

    os.rm(tmpdir)
end

function build_cppfiles(target, jobgraph, sourcebatch, opt)
    local toolchain = assert(target:toolchain("verilator"), 'we need to set_toolchains("verilator") in target("%s")', target:name())
    local verilator = assert(toolchain:config("verilator"), "verilator not found!")
    local autogendir = path.join(target:autogendir(), "rules", "verilator")
    local targetname = target:name()
    local cmakefile = path.join(autogendir, targetname .. ".cmake")

    -- build verilog files
    depend.on_changed(function()
        local argv = {"--cc", "--make", "cmake", "--prefix", targetname, "--Mdir", autogendir}
        local flags = target:values("verilator.flags")
        if flags then
            table.join2(argv, flags)
        end
        local language_flags = _get_lanuage_flags(target)
        if language_flags then
            table.join2(argv, language_flags)
        end
        local sourcefiles = sourcebatch.sourcefiles
        for _, sourcefile in ipairs(sourcefiles) do
            progress.show(opt.progress or 0, "${color.build.object}compiling.verilog %s", sourcefile)
            -- we need to use slashes to fix it on windows
            -- @see https://github.com/verilator/verilator/issues/3873
            if is_host("windows") then
                sourcefile = sourcefile:gsub("\\", "/")
            end
            table.insert(argv, sourcefile)
        end

        -- generate c++ sourcefiles
        os.vrunv(verilator, argv, {envs = toolchain:runenvs()})

    end, {dependfile = cmakefile .. ".d",
          files = sourcebatch.sourcefiles,
          changed = target:is_rebuilt(),
          lastmtime = os.mtime(cmakefile)})

    -- get compiled source files
    local sourcefiles = _get_sourcefiles_from_cmake(target, cmakefile)

    -- do build
    local sourcebatch_cpp = {
        rulename = "c++.build",
        sourcekind = "cxx",
        sourcefiles = sourcefiles,
        objectfiles = {},
        dependfiles = {}}
    for _, sourcefile in ipairs(sourcefiles) do
        local objectfile = target:objectfile(sourcefile)
        local dependfile = target:dependfile(objectfile)
        table.insert(target:objectfiles(), objectfile)
        table.insert(sourcebatch_cpp.objectfiles, objectfile)
        table.insert(sourcebatch_cpp.dependfiles, dependfile)
    end
    build_objectfiles(target, jobgraph, sourcebatch_cpp, opt)
end

function buildcmd_vfiles(target, batchcmds, sourcebatch, opt)
    local toolchain = assert(target:toolchain("verilator"), 'we need to set_toolchains("verilator") in target("%s")', target:name())
    local verilator = assert(toolchain:config("verilator"), "verilator not found!")
    local autogendir = path.join(target:autogendir(), "rules", "verilator")
    local targetname = target:name()
    local cmakefile = path.join(autogendir, targetname .. ".cmake")
    local dependfile = cmakefile .. ".d"

    local argv = {"--cc", "--make", "cmake", "--prefix", targetname, "--Mdir", path(autogendir)}
    local flags = target:values("verilator.flags")
    if flags then
        table.join2(argv, flags)
    end
    local language_flags = _get_lanuage_flags(target)
    if language_flags then
        table.join2(argv, language_flags)
    end
    local sourcefiles = sourcebatch.sourcefiles
    for _, sourcefile in ipairs(sourcefiles) do
        batchcmds:show_progress(opt.progress, "${color.build.object}compiling.verilog %s", sourcefile)
        table.insert(argv, path(sourcefile, function (v)
            -- we need to use slashes to fix it on windows
            -- @see https://github.com/verilator/verilator/issues/3873
            if is_host("windows") then
                v = v:gsub("\\", "/")
            end
            return v
        end))
    end

    -- generate c++ sourcefiles
    batchcmds:vrunv(verilator, argv, {envs = toolchain:runenvs()})
    batchcmds:add_depfiles(sourcefiles)
    batchcmds:set_depmtime(os.mtime(cmakefile))
    batchcmds:set_depcache(dependfile)
end

function buildcmd_cppfiles(target, batchcmds, sourcebatch, opt)
    local toolchain = assert(target:toolchain("verilator"), 'we need set_toolchains("verilator") in target("%s")', target:name())
    local verilator = assert(toolchain:config("verilator"), "verilator not found!")
    local autogendir = path.join(target:autogendir(), "rules", "verilator")
    local targetname = target:name()
    local cmakefile = path.join(autogendir, targetname .. ".cmake")
    local dependfile = path.join(autogendir, targetname .. ".build.d")

    -- get compiled source files
    local sourcefiles = _get_sourcefiles_from_cmake(target, cmakefile)

    -- do build
    for _, sourcefile in ipairs(sourcefiles) do
        local objectfile = target:objectfile(sourcefile)
        batchcmds:show_progress(opt.progress, "${color.build.object}compiling.$(mode) %s", path.filename(sourcefile))
        batchcmds:compile(sourcefile, objectfile)
        table.insert(target:objectfiles(), objectfile)
    end
    batchcmds:add_depfiles(sourcefiles)
    batchcmds:set_depmtime(os.mtime(dependfile))
    batchcmds:set_depcache(dependfile)
end
