package cmd

import (
	"io"
	"text/template"

	"go.fifitido.net/cmd/opt"
)

func WriteZshCompletions(out io.Writer, rootCmd *Command) error {
	return zshTpl.Execute(out, map[string]any{
		"RootCmd":    rootCmd,
		"GlobalOpts": opt.Globals(),
	})
}

// TODO: Fix indentation and other spacing
var zshTpl = template.Must(template.New("zsh").Funcs(tplFuncs).Parse(`
{{- $rootCmd := .RootCmd -}}
{{- $progName := $rootCmd.Name -}}
{{- $varName := under $rootCmd.Name -}}

{{- define "cmd" }}
{{- $varPrefix := varPrefix .Cmd.CommandPath -}}
{{- if not .Cmd.IsRoot}}
{{ .Cmd.Name }})
{{ end -}}
  {{ if gt (len .Cmd.Subcommands) 0 -}}
  local -a {{ $varPrefix }}commands
  {{ $varPrefix }}commands=(
    {{- range .Cmd.Subcommands}}
    '{{ .Name }}:{{ .ShortDescription }}'
    {{- end }}
  )
  {{ end }}

  {{- if or (gt (len .Cmd.Opts) 0) (gt (len .Cmd.Subcommands) 0) -}}
  _arguments
  {{- end -}}
  {{- range .Cmd.Opts -}}
    {{- if ne .Name ""}} \
    '--{{ .Name }}[{{ .Description }}]'
    {{- end }}
    {{- if ne .ShortName ""}} \
    '-{{ .ShortName }}[{{ .Description }}]'
    {{- end }}
  {{- end }}
  {{- if gt (len .Cmd.Subcommands) 0 -}}
    {{ " " }}\
    '1: :{_describe 'command' {{ $varPrefix }}commands}' \
    '*:: :->args'
  
  case $state in
    args)
      case $words[1] in
        {{- range .Cmd.Subcommands }}
          {{ template "cmd" (map "Cmd" .) }}
        {{- end }}
      esac
      ;;
  esac
  {{- end }}
{{- if not .Cmd.IsRoot}}
  ;;
{{ end }}
{{ end -}}

function _{{ $varName }} {
  {{ template "cmd" (map "Cmd" .RootCmd) -}}

  {{- if gt (len .GlobalOpts) 0 }}
  _arguments
    {{- range .GlobalOpts -}}
      {{- if ne .Name ""}} \
      '--{{ .Name }}[{{ .Description }}]'
      {{- end }}
      {{- if ne .ShortName ""}} \
      '-{{ .ShortName }}[{{ .Description }}]'
      {{- end }}
    {{- end }}
  {{- end }}
}

compdef _{{ $varName }} {{ $progName }}
`))