package gtest

import (
	"io"
	"log"
        "os"
	"golang.flu0r1ne.net/planr"
        "path"
        "text/template"
)

type cmakeUnit struct {
  ExeNm           string
  File            string
  Srcdir          string
  IncludeSrc      bool 
  Srcs            string
  CompilerOptions string
};

func cmakeUnits(e []executable, dirs planr.DirConfig) []cmakeUnit {
  
  units := make([]cmakeUnit, len(e))
  for i, exe := range e {
    testpath := path.Join(dirs.Tests(), exe.testpath)
    srclist  := srcList(dirs.Src(), exe.srcs)

    units[i] = cmakeUnit { 
      ExeNm:  exe.exeNm,
      File:   testpath,
      IncludeSrc: exe.includeSrc,
      Srcdir: dirs.Src(),
      Srcs:   srclist,
      CompilerOptions: compilerOptionsCmake(exe),
    }
  }

  return units
}

func generateCmakeScript(out string, units []cmakeUnit) {
  file, err := os.OpenFile(out, os.O_RDWR | os.O_CREATE, 0644)
  defer func () {
    err := file.Close()

    if err != nil {
      log.Fatal(err)
    }
  }()

  if err != nil {
    log.Fatalf("Could not open CMakeFile (%s)\n%v", out, err)
  }

  writeCmakeBoilerplate(file)
  
  tmpl := unitTemplate()

  for _, unit := range units {
    if err := tmpl.Execute(file, unit); err != nil {
      log.Fatalf("Failed to generate unit %s: %v", unit.ExeNm, err);
    }
  }
}

func compilerOptionsCmake(e executable) string {
  if e.compilerOptions == "" {
    return ""
  }

  return "target_compile_options(\"" + e.exeNm + "\" PRIVATE " + e.compilerOptions + ")";
}

// TODO: Add comments
func unitTemplate() *template.Template {
  tmpl, err := template.New("gtest_unit").Parse(`

################################################

## {{.ExeNm}}

add_executable(
  "{{.ExeNm}}"
  "{{.File}}"
  {{.Srcs}}
)

{{.CompilerOptions}}

{{ if .IncludeSrc }}

target_include_directories("{{.ExeNm}}" PRIVATE "{{.Srcdir}}")

{{ end }}

target_link_libraries(
  "{{.ExeNm}}"
  gtest_main
)

gtest_discover_tests(
  "{{.ExeNm}}"
)
`)

  if err != nil {
    log.Fatalf("Cannot load Gtest unit template %v", err)
  }

  return tmpl
}

const GOOGLE_TEST_URL = "https://github.com/google/googletest/archive/609281088cfefc76f9d0ce82e1ff6c30cc3591e5.zip"

func writeCmakeBoilerplate(w io.Writer) {
  tmpl := boilderTemplate()
  
  tmpl.Execute(w, struct {
    Url     string
    Version string
  }{
    Url: GOOGLE_TEST_URL,
    Version: planr.VERSION,
  })
}

// TODO: Make CXX Version Editable 
func boilderTemplate() *template.Template {
  tmpl, err := template.New("gtest_boilerplate").Parse(`
# AUTOMATICALLY GENERATED BY PLANR VERSION {{.Version}}

cmake_minimum_required (VERSION 3.1.0)

project(PlanRGtestAdapter)

include(FetchContent)
FetchContent_Declare(
  googletest
  URL {{.Url}}
)

set(CMAKE_CXX_STANDARD 17)

include(GoogleTest)
FetchContent_MakeAvailable(googletest)
`)
  
  if err != nil {
    log.Fatalf("Cannot load Gtest Cmake boilerplate")
  }

  return tmpl
}