// Copyright 2024 Matthew Rich <matthewrich.conf@gmail.com>. All rights reserved.

package main

import (
	"io"
  "os"
  "flag"
  "log"
	"log/slog"
	"errors"
_	"fmt"
_ "gopkg.in/yaml.v3"
  "decl/internal/resource"
)


func main() {

  var programLevel = new(slog.LevelVar)
  logger := slog.New(slog.NewTextHandler(os.Stderr, &slog.HandlerOptions{Level: programLevel}))
  slog.SetDefault(logger)
  if debugLogging,ok := os.LookupEnv("DECL_DEBUG"); ok && debugLogging != "" {
    programLevel.Set(slog.LevelDebug)
  } else {
    programLevel.Set(slog.LevelError)
  }

  file := flag.String("resource-file", "", "Resource file path")
  resourceUri := flag.String("import-resource", "", "Add an existing resource")
  
  flag.Parse()

  var resourceFile *os.File
  var inputFileErr error

	slog.Info("args", "resource-file", *file, "import-resource", *resourceUri)
  if *file == "-" {
    if stdinInfo, stdinErr := os.Stdin.Stat(); stdinErr == nil {
      if (stdinInfo.Mode() & os.ModeCharDevice) == 0 {
        resourceFile = os.Stdin
      }
    } else {
      inputFileErr = stdinErr
    }
	} else if *file != "" {
    resourceFile,inputFileErr = os.Open(*file)
  }

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

	documents := make([]*resource.Document, 0, 100)
	decoder := resource.NewYAMLDecoder(resourceFile)
	encoder := resource.NewYAMLEncoder(os.Stdout)
	index := 0

	slog.Info("loading resource document", "file", resourceFile)

	documents = append(documents, resource.NewDocument())
	if resourceFile != nil {
		for {
			d := documents[index]
		  e := decoder.Decode(d)
			if errors.Is(e, io.EOF) {
				if len(documents) > 1 {
					documents[index] = nil
				}
				break
			}
			if e != nil {
				log.Fatal(e)
			}
			if validationErr := d.Validate(); validationErr != nil {
				log.Fatal(validationErr)
			}
			if applyErr := d.Apply(); applyErr != nil {
				log.Fatal(applyErr)
			}
			documents = append(documents, resource.NewDocument())
			index++
		}
	}

	for _,document := range documents {
		if document != nil {
		  if *resourceUri != "" {
				slog.Info("importing resource", "resource", *resourceUri)
				if addResourceErr := document.AddResource(*resourceUri); addResourceErr != nil {
					log.Fatal(addResourceErr)
				}
			}
			if documentGenerateErr := encoder.Encode(document); documentGenerateErr != nil {
				log.Fatal(documentGenerateErr)
			}
		}
	}
}