import nre
import os
import ospaths
import osproc
import parsecfg
import pegs
import ropes
import sequtils
import streams
import strutils
import tables

var DONE: seq[string] = @[]
var DONE_INLINE: seq[string] = @[]

var CONFIG: Config
var FILTER = ""
var QUOTES = true
var OUTPUT = ""
var INCLUDES: seq[string] = @[]
var EXCLUDES: seq[string] = @[]
var RENAMES = initTable[string, string]()
var WILDCARDS = newConfig()

const DOC = """
Nimgen is a helper for c2nim to simpilfy and automate the wrapping of C libraries

Usage:
  nimgen [options] <file.cfg>...

Options:
  -f    delete all artifacts and regenerate
"""

# ###
# Helpers

proc execProc(cmd: string): string =
    var p = startProcess(cmd, options = {poStdErrToStdOut, poUsePath, poEvalCommand})

    result = ""
    var outp = outputStream(p)
    var line = newStringOfCap(120).TaintedString
    while true:
        if outp.readLine(line):
            result.add(line)
            result.add("\n")
        elif not running(p): break

    var x = p.peekExitCode()
    if x != 0:
        echo "Command failed: " & $x
        echo cmd
        echo result
        quit(1)

proc extractZip(zipfile: string) =
    var cmd = "unzip -o $#"
    if defined(Windows):
        cmd = "powershell -nologo -noprofile -command \"& { Add-Type -A 'System.IO.Compression.FileSystem'; [IO.Compression.ZipFile]::ExtractToDirectory('$#', '.'); }\""

    setCurrentDir(OUTPUT)
    defer: setCurrentDir("..")

    echo "Extracting " & zipfile
    discard execProc(cmd % zipfile)

proc downloadUrl(url: string) =
    let file = url.extractFilename()
    let ext = file.splitFile().ext.toLowerAscii()

    var cmd = "curl $# -o $#"
    if defined(Windows):
        cmd = "powershell wget $# -OutFile $#"

    if not (ext == ".zip" and fileExists(OUTPUT/file)):
        echo "Downloading " & file
        discard execProc(cmd % [url, OUTPUT/file])

    if ext == ".zip":
        extractZip(file)

proc gitReset() =
    echo "Resetting Git repo"

    setCurrentDir(OUTPUT)
    defer: setCurrentDir("..")

    discard execProc("git reset --hard HEAD")

proc gitRemotePull(url: string, pull=true) =
    if dirExists(OUTPUT/".git"):
        if pull:
            gitReset()
        return

    setCurrentDir(OUTPUT)
    defer: setCurrentDir("..")

    echo "Setting up Git repo"
    discard execProc("git init .")
    discard execProc("git remote add origin " & url)

    if pull:
        echo "Checking out artifacts"
        discard execProc("git pull --depth=1 origin master")

proc gitSparseCheckout(plist: string) =
    let sparsefile = ".git/info/sparse-checkout"
    if fileExists(OUTPUT/sparsefile):
        gitReset()
        return

    setCurrentDir(OUTPUT)
    defer: setCurrentDir("..")

    discard execProc("git config core.sparsecheckout true")
    writeFile(sparsefile, plist)

    echo "Checking out artifacts"
    discard execProc("git pull --depth=1 origin master")

proc getKey(ukey: string): tuple[key: string, val: bool] =
    var kv = ukey.replace(re"\..*", "").split("-", 1)
    if kv.len() == 1:
        kv.add("")

    if (kv[1] == "") or
        (kv[1] == "win" and defined(Windows)) or
        (kv[1] == "lin" and defined(Linux)) or
        (kv[1] == "osx" and defined(MacOSX)):
        return (kv[0], true)

    return (kv[0], false)

# ###
# File loction

proc getNimout(file: string, rename=true): string =
    result = file.splitFile().name.replace(re"[\-\.]", "_") & ".nim"
    if OUTPUT != "":
        result = OUTPUT/result

    if not rename:
        return

    if RENAMES.hasKey(file):
        result = RENAMES[file]

    if not dirExists(parentDir(result)):
        createDir(parentDir(result))

proc exclude(file: string): bool =
    for excl in EXCLUDES:
        if excl in file:
            return true
    return false

proc search(file: string): string =
    if exclude(file):
        return ""

    result = file
    if file.splitFile().ext == ".nim":
        result = getNimout(file)
    elif not fileExists(result) and not dirExists(result):
        var found = false
        for inc in INCLUDES:
            result = inc/file
            if fileExists(result) or dirExists(result):
                found = true
                break
        if not found:
            echo "File doesn't exist: " & file
            quit(1)

    return result.replace(re"[\\/]", $DirSep)

# ###
# Loading / unloading

template withFile(file: string, body: untyped): untyped =
    if fileExists(file):
        var f: File
        while true:
            try:
                f = open(file)
                break
            except:
                sleep(100)

        var contentOrig = f.readAll()
        f.close()
        var content {.inject.} = contentOrig

        body

        if content != contentOrig:
            var f = open(file, fmWrite)
            write(f, content)
            f.close()
    else:
        echo "Missing file " & file

# ###
# Manipulating content

proc prepend(file: string, data: string, search="") =
    withFile(file):
        if search == "":
            content = data & content
        else:
            let idx = content.find(search)
            if idx != -1:
                content = content[0..<idx] & data & content[idx..<content.len()]

proc append(file: string, data: string, search="") =
    withFile(file):
        if search == "":
            content &= data
        else:
            let idx = content.find(search)
            let idy = idx + search.len()
            if idx != -1:
                content = content[0..<idy] & data & content[idy..<content.len()]

proc freplace(file: string, pattern: string, repl="") =
    withFile(file):
        if pattern in content:
            content = content.replace(pattern, repl)

proc freplace(file: string, pattern: Regex, repl="") =
    withFile(file):
        if content.find(pattern).isSome():
            if "$#" in repl:
                for m in content.findIter(pattern):
                    content = content.replace(m.match, repl % m.captures[0])
            else:
                content = content.replace(pattern, repl)

proc comment(file: string, pattern: string, numlines: string) =
    let ext = file.splitFile().ext.toLowerAscii()
    let cmtchar = if ext == ".nim": "#" else: "//"
    withFile(file):
        var idx = content.find(pattern)
        var num = 0
        try:
            num = numlines.parseInt()
        except ValueError:
            echo "Bad comment value, should be integer: " & numlines
        if idx != -1:
            for i in 0 .. num-1:
                if idx >= content.len():
                    break
                content = content[0..<idx] & cmtchar & content[idx..<content.len()]
                while idx < content.len():
                    idx += 1
                    if content[idx] == '\L':
                        idx += 1
                        break

proc rename(file: string, renfile: string) =
    if file.splitFile().ext == ".nim":
        return

    var
        nimout = getNimout(file, false)
        newname = renfile.replace("$nimout", extractFilename(nimout))

    #if newname =~ peg"(!\$.)*{'$replace'\s*'('\s*{(!\,\S)+}\s*','\s*{(!\)\S)+}\s*')'}":
    if newname =~ peg"(!\$.)*{'$replace'\s*'('\s*{(!\)\S)+}')'}":
        var final = nimout.extractFilename()
        for entry in matches[1].split(","):
            let spl = entry.split("=")
            if spl.len() != 2:
                echo "Bad replace syntax: " & renfile
                quit(1)

            var
                srch = spl[0].strip()
                repl = spl[1].strip()

            final = final.replace(srch, repl)
        newname = newname.replace(matches[0], final)

    RENAMES[file] = OUTPUT/newname

proc compile(dir="", file=""): string =
    proc fcompile(file: string): string =
        return "{.compile: \"$#\".}" % file.replace("\\", "/")

    var data = ""
    if dir != "" and dirExists(dir):
        for f in walkFiles(dir / "*.c"):
            data &= fcompile(f) & "\n"

    if file != "" and fileExists(file):
        data &= fcompile(file) & "\n"

    return data

proc fixFuncProtos(file: string) =
    withFile(file):
        for fp in content.findIter(re"(?m)(^.*?)[ ]*\(\*(.*?)\((.*?)\)\)[ \r\n]*\((.*?[\r\n]*.*?)\);"):
            var tdout = "typedef $# (*type_$#)($#);\n" % [fp.captures[0], fp.captures[1], fp.captures[3]] &
                "type_$# $#($#);" % [fp.captures[1], fp.captures[1], fp.captures[2]]
            content = content.replace(fp.match, tdout)

# ###
# Convert to Nim

proc getIncls(file: string, inline=false): seq[string] =
    result = @[]
    if inline and file in DONE_INLINE:
        return

    withFile(file):
        for f in content.findIter(re"(?m)^\s*#\s*include\s+(.*?)$"):
            var inc = f.captures[0].strip()
            if ((QUOTES and inc.contains("\"")) or (FILTER != "" and FILTER in inc)) and (not exclude(inc)):
                result.add(
                    inc.replace(re"""[<>"]""", "").replace(re"\/[\*\/].*$", "").strip())

        result = result.deduplicate()

    DONE_INLINE.add(file)

    if inline:
        var sres = newSeq[string]()
        for incl in result:
            let sincl = search(incl)
            if sincl == "":
                continue

            sres.add(getIncls(sincl, inline))
        result.add(sres)

    result = result.deduplicate()

proc getDefines(file: string, inline=false): string =
    result = ""
    if inline:
        var incls = getIncls(file, inline)
        for incl in incls:
            let sincl = search(incl)
            if sincl != "":
                echo "Inlining " & sincl
                result &= getDefines(sincl)
    withFile(file):
        for def in content.findIter(re"(?m)^(\s*#\s*define\s+[\w\d_]+\s+[\d\-.xf]+)(?:\r|//|/*).*?$"):
            result &= def.captures[0] & "\n"

proc runPreprocess(file, ppflags, flags: string, inline: bool): string =
    var pproc = "gcc"
    if flags.contains("cpp"):
        pproc = "g++"
    var cmd = "$# -E $# $#" % [pproc, ppflags, file]
    for inc in INCLUDES:
        cmd &= " -I " & inc

    # Run preprocessor
    var data = execProc(cmd)

    # Include content only from file
    var rdata: Rope
    var start = false
    var sfile = file.replace("\\", "/")
    if inline:
        sfile = sfile.parentDir()
    for line in data.splitLines():
        if line.strip() != "":
            if line[0] == '#' and not line.contains("#pragma"):
                start = false
                if sfile in line.replace("\\", "/").replace("//", "/"):
                    start = true
                if not ("\\" in line) and not ("/" in line) and extractFilename(sfile) in line:
                    start = true
            else:
                if start:
                    rdata.add(
                        line.replace("_Noreturn", "")
                            .replace("(())", "")
                            .replace("WINAPI", "")
                            .replace("__attribute__", "")
                            .replace("extern \"C\"", "")
                            .replace(re"\(\([_a-z]+?\)\)", "")
                            .replace(re"\(\(__format__[\s]*\(__[gnu_]*printf__, [\d]+, [\d]+\)\)\);", ";") & "\n"
                    )
    return $rdata

proc runCtags(file: string): string =
    var cmd = "ctags -o - --fields=+S+K --c-kinds=p --file-scope=no " & file
    var fps = execProc(cmd)

    var fdata = ""
    for line in fps.splitLines():
        var spl = line.split(re"\t")
        if spl.len() > 4:
            if spl[0] != "main":
                var fn = ""
                var match = spl[2].find(re"/\^(.*?)\(")
                if match.isSome():
                    fn = match.get().captures[0]
                    fn &= spl[4].replace("signature:", "") & ";"
                    fdata &= fn & "\n"

    return fdata

proc runFile(file: string, cfgin: OrderedTableRef)

proc c2nim(fl, outfile, flags, ppflags: string, recurse, inline, preprocess, ctags, defines: bool, dynlib, compile, pragma: seq[string] = @[]) =
    var file = search(fl)
    if file == "":
        return

    if file in DONE:
        return

    echo "Processing $# => $#" % [file, outfile]
    DONE.add(file)

    fixFuncProtos(file)

    var incout = ""
    if recurse:
        var incls = getIncls(file)
        for inc in incls:
            var cfg = newOrderedTable[string, string]()
            if flags != "": cfg["flags"] = flags
            if ppflags != "": cfg["ppflags"] = ppflags
            if recurse: cfg["recurse"] = $recurse
            if preprocess: cfg["preprocess"] = $preprocess
            if ctags: cfg["ctags"] = $ctags
            if defines: cfg["defines"] = $defines
            for i in dynlib:
                cfg["dynlib." & i] = i
            runFile(inc, cfg)

            incout &= "import $#\n" % inc.search().getNimout()[0 .. ^5] #inc.splitFile().name.replace(re"[\-\.]", "_") & "\n"

    var cfile = file
    if preprocess:
        cfile = "temp-$#.c" % [outfile.extractFilename()]
        writeFile(cfile, runPreprocess(file, ppflags, flags, inline))
    elif ctags:
        cfile = "temp-$#.c" % [outfile.extractFilename()]
        writeFile(cfile, runCtags(file))

    if defines and (preprocess or ctags):
        prepend(cfile, getDefines(file, inline))

    var extflags = ""
    var passC = ""
    var outlib = ""
    var outpragma = ""

    passC = "import strutils\n"
    for inc in INCLUDES:
        passC &= ("""{.passC: "-I\"" & gorge("nimble path $#").strip() & "/$#\"".}""" % [OUTPUT, inc]) & "\n"

    for prag in pragma:
        outpragma &= "{." & prag & ".}\n"

    let fname = file.splitFile().name.replace(re"[\.\-]", "_")
    if dynlib.len() != 0:
        let win = "when defined(Windows):\n"
        let lin = "when defined(Linux):\n"
        let osx = "when defined(MacOSX):\n"
        var winlib, linlib, osxlib: string = ""
        for dl in dynlib:
            let lib = "  const dynlib$# = \"$#\"\n" % [fname, dl]
            let ext = dl.splitFile().ext
            if ext == ".dll":
                winlib &= lib
            elif ext == ".so":
                linlib &= lib
            elif ext == ".dylib":
                osxlib &= lib

        if winlib != "":
            outlib &= win & winlib & "\n"
        if linlib != "":
            outlib &= lin & linlib & "\n"
        if osxlib != "":
            outlib &= osx & osxlib & "\n"

        if outlib != "":
            extflags &= " --dynlib:dynlib$#" % fname
    else:
        passC &= "const header$# = \"$#\"\n" % [fname, fl]
        extflags = "--header:header$#" % fname

    # Run c2nim on generated file
    var cmd = "c2nim $# $# --out:$# $#" % [flags, extflags, outfile, cfile]
    when defined(windows):
        cmd = "cmd /c " & cmd
    discard execProc(cmd)

    if preprocess or ctags:
        try:
            removeFile(cfile)
        except:
            discard

    # Import nim modules
    if recurse:
        prepend(outfile, incout)

    # Nim doesn't like {.cdecl.} for type proc()
    freplace(outfile, re"(?m)(.*? = proc.*?){.cdecl.}", "$#")
    freplace(outfile, " {.cdecl.})", ")")

    # Include {.compile.} directives
    for cpl in compile:
        let fcpl = search(cpl)
        if getFileInfo(fcpl).kind == pcFile:
            prepend(outfile, compile(file=fcpl))
        else:
            prepend(outfile, compile(dir=fcpl))

    # Add any pragmas
    if outpragma != "":
        prepend(outfile, outpragma)

    # Add header file and include paths
    if passC != "":
        prepend(outfile, passC)

    # Add dynamic library
    if outlib != "":
        prepend(outfile, outlib)

# ###
# Processor

proc runFile(file: string, cfgin: OrderedTableRef) =
    var cfg = cfgin
    var sfile = search(file)

    for pattern in WILDCARDS.keys():
        let pat = pattern.replace(".", "\\.").replace("*", ".*").replace("?", ".?")
        if file.find(re(pat)).isSome():
            echo "Appending " & file & " " & pattern
            for key in WILDCARDS[pattern].keys():
                cfg[key & "." & pattern] = WILDCARDS[pattern][key]

    var srch = ""
    var compile: seq[string] = @[]
    var dynlib: seq[string] = @[]
    var pragma: seq[string] = @[]
    for act in cfg.keys():
        let (action, val) = getKey(act)
        if val == true:
            if action == "create":
                createDir(file.splitPath().head)
                writeFile(file, cfg[act])
            elif action in @["prepend", "append", "replace", "comment", "rename", "compile", "dynlib", "pragma"] and sfile != "":
                if action == "prepend":
                    if srch != "":
                        prepend(sfile, cfg[act], cfg[srch])
                    else:
                        prepend(sfile, cfg[act])
                elif action == "append":
                    if srch != "":
                        append(sfile, cfg[act], cfg[srch])
                    else:
                        append(sfile, cfg[act])
                elif action == "replace":
                    if srch != "":
                        freplace(sfile, cfg[srch], cfg[act])
                elif action == "comment":
                    if srch != "":
                        comment(sfile, cfg[srch], cfg[act])
                elif action == "rename":
                    rename(sfile, cfg[act])
                elif action == "compile":
                    compile.add(cfg[act])
                elif action == "dynlib":
                    dynlib.add(cfg[act])
                elif action == "pragma":
                    pragma.add(cfg[act])
                srch = ""
            elif action == "search":
                srch = act

    if file.splitFile().ext != ".nim":
        var recurse = false
        var inline = false
        var preprocess = false
        var ctags = false
        var defines = false
        var noprocess = false
        var flags = "--stdcall"
        var ppflags = ""

        for act in cfg.keys():
            if cfg[act] == "true":
                if act == "recurse":
                    recurse = true
                elif act == "inline":
                    inline = true
                elif act == "preprocess":
                    preprocess = true
                elif act == "ctags":
                    ctags = true
                elif act == "defines":
                    defines = true
                elif act == "noprocess":
                    noprocess = true
            elif act == "flags":
                flags = cfg[act]
            elif act == "ppflags":
                ppflags = cfg[act]

        if recurse and inline:
            echo "Cannot use recurse and inline simultaneously"
            quit(1)

        if not noprocess:
            c2nim(file, getNimout(sfile), flags, ppflags, recurse, inline, preprocess, ctags, defines, dynlib, compile, pragma)

proc runCfg(cfg: string) =
    if not fileExists(cfg):
        echo "Config doesn't exist: " & cfg
        quit(1)

    CONFIG = loadConfig(cfg)

    if CONFIG.hasKey("n.global"):
        if CONFIG["n.global"].hasKey("output"):
            OUTPUT = CONFIG["n.global"]["output"]
            if dirExists(OUTPUT):
                if "-f" in commandLineParams():
                    try:
                        removeDir(OUTPUT)
                    except OSError:
                        echo "Directory in use: " & OUTPUT
                        quit(1)
                else:
                    for f in walkFiles(OUTPUT/"*.nim"):
                        try:
                            removeFile(f)
                        except OSError:
                            echo "Unable to delete: " & f
                            quit(1)
            createDir(OUTPUT)

        if CONFIG["n.global"].hasKey("filter"):
            FILTER = CONFIG["n.global"]["filter"]
        if CONFIG["n.global"].hasKey("quotes"):
            if CONFIG["n.global"]["quotes"] == "false":
                QUOTES = false

    if CONFIG.hasKey("n.include"):
        for inc in CONFIG["n.include"].keys():
            INCLUDES.add(inc)

    if CONFIG.hasKey("n.exclude"):
        for excl in CONFIG["n.exclude"].keys():
            EXCLUDES.add(excl)

    if CONFIG.hasKey("n.prepare"):
        for prep in CONFIG["n.prepare"].keys():
            let (key, val) = getKey(prep)
            if val == true:
                if key == "download":
                    downloadUrl(CONFIG["n.prepare"][prep])
                elif key == "extract":
                    extractZip(CONFIG["n.prepare"][prep])
                elif key == "git":
                    gitRemotePull(CONFIG["n.prepare"][prep])
                elif key == "gitremote":
                    gitRemotePull(CONFIG["n.prepare"][prep], false)
                elif key == "gitsparse":
                    gitSparseCheckout(CONFIG["n.prepare"][prep])
                elif key == "execute":
                    discard execProc(CONFIG["n.prepare"][prep])

    if CONFIG.hasKey("n.wildcard"):
        var wildcard = ""
        for wild in CONFIG["n.wildcard"].keys():
            let (key, val) = getKey(wild)
            if val == true:
                if key == "wildcard":
                    wildcard = CONFIG["n.wildcard"][wild]
                else:
                    WILDCARDS.setSectionKey(wildcard, wild, CONFIG["n.wildcard"][wild])

    for file in CONFIG.keys():
        if file in @["n.global", "n.include", "n.exclude", "n.prepare", "n.wildcard"]:
            continue

        runFile(file, CONFIG[file])

# ###
# Main loop

for i in commandLineParams():
    if i != "-f":
        runCfg(i)