package smplt

import (
	"io"
	"mime"
	"path"
	"strings"
	"text/template"
)

const (
	SIMPLATE_TYPE_RENDERED   = "rendered"
	SIMPLATE_TYPE_STATIC     = "static"
	SIMPLATE_TYPE_NEGOTIATED = "negotiated"
	SIMPLATE_TYPE_JSON       = "json"
)

var (
	simplateGenFileTmpl = template.Must(template.New("smpltgen").Parse(strings.Replace(`
  /* GENERATED FILE - DO NOT EDIT */
  /* Rebuild with simplate filesystem parsing thingy! */
  package smpltgen

  import (
      "text/template"
  )

  {{.InitPage.Body}}

  const (
      SIMPLATE_TMPL_{{.ConstName}} = __BACKTICK__{{.TemplatePage.Body}}__BACKTICK__
  )

  var (
      simplateTmpl{{.FuncName}} = template.Must(template.New("{{.FuncName}}").Parse(SIMPLATE_TMPL_{{.ConstName}}))
  )

  func SimplateHandlerFunc{{.FuncName}}(w http.ResponseWriter, req *http.Request) {
      {{range .LogicPages}}
        {{.Body}}
      {{end}}
  }

`, "__BACKTICK__", "`", -1)))
)

type Simplate struct {
	Filename     string
	Type         string
	ContentType  string
	InitPage     *SimplatePage
	LogicPages   []*SimplatePage
	TemplatePage *SimplatePage
}

type SimplatePage struct {
	Body string
}

func SimplateFromString(filename, content string) *Simplate {
	rawPages := strings.Split(content, "")
	nbreaks := len(rawPages) - 1

	s := &Simplate{
		Filename:    filename,
		Type:        SIMPLATE_TYPE_STATIC,
		ContentType: mime.TypeByExtension(path.Ext(filename)),
	}

	if nbreaks == 1 || nbreaks == 2 {
		s.InitPage = &SimplatePage{Body: rawPages[0]}
		s.LogicPages = append(s.LogicPages, &SimplatePage{Body: rawPages[1]})

		if s.ContentType == "application/json" {
			s.Type = SIMPLATE_TYPE_JSON
		} else {
			s.Type = SIMPLATE_TYPE_RENDERED
			s.TemplatePage = &SimplatePage{Body: rawPages[2]}
		}

		return s
	}

	if nbreaks > 2 {
		s.Type = SIMPLATE_TYPE_NEGOTIATED
		s.InitPage = &SimplatePage{Body: rawPages[0]}

		for _, rawPage := range rawPages {
			s.LogicPages = append(s.LogicPages, &SimplatePage{Body: rawPage})
		}

		return s
	}

	return s
}

func (me *Simplate) Execute(wr io.Writer) error {
	return simplateGenFileTmpl.Execute(wr, me)
}

func (me *Simplate) escapedFilename() string {
	lessDots := strings.Replace(me.Filename, ".", "-DOT-", -1)
	lessSlashes := strings.Replace(lessDots, "/", "-SLASH-", -1)
	return strings.Replace(lessSlashes, " ", "-SPACE-", -1)
}

func (me *Simplate) OutputName() string {
	if me.Type == SIMPLATE_TYPE_STATIC {
		return me.Filename
	}

	return me.escapedFilename() + ".go"
}

func (me *Simplate) FuncName() string {
	escaped := me.escapedFilename()
	parts := strings.Split(escaped, "-")
	for i, part := range parts {
		var capitalized []string
		capitalized = append(capitalized, strings.ToUpper(string(part[0])))
		capitalized = append(capitalized, strings.ToLower(part[1:]))
		parts[i] = strings.Join(capitalized, "")
	}

	return strings.Join(parts, "")
}

func (me *Simplate) ConstName() string {
	escaped := me.escapedFilename()
	uppered := strings.ToUpper(escaped)
	return strings.Replace(uppered, "-", "_", -1)
}