package models

import (
	"encoding/json"
	"errors"
	"fmt"
	"os"
	"path/filepath"

	"github.com/rs/zerolog/log"
)

const (
	MainDir string = ".homeserver"

	ComposeFile string = "docker-compose.deploy.yml"
	EnvFile     string = ".env"
	NginxFile          = "nginx.conf"

	ConfFile = "hmdeploy.json"
)

var ErrProjectConfFile = errors.New("project error")

func getFilepath(baseDir, filePath string) (string, error) {
	filePath = filepath.Join(baseDir, filePath)

	if !filepath.IsAbs(filePath) {
		filePath, err := filepath.Abs(filePath) //nolint: govet
		if err != nil {
			return filePath, fmt.Errorf(
				"%w, file=%s, err=%v",
				ErrProjectConfFile,
				filePath,
				err,
			)
		}
	}

	fileInfo, err := os.Stat(filePath)
	if err != nil {
		return filePath, fmt.Errorf(
			"%w, file=%s, err=%v",
			ErrProjectConfFile,
			filePath,
			err,
		)
	}

	if fileInfo.IsDir() {
		return filePath, fmt.Errorf(
			"%w, file=%s, err=%s",
			ErrProjectConfFile,
			filePath,
			"must be a file",
		)
	}

	return filePath, nil
}

// Project handles the details and file informations of your project.
type Project struct {
	Name string `json:"name"`
	Dir  string
	Deps struct {
		EnvFile     string `json:"env"`
		ComposeFile string `json:"compose"`
		NginxFile   string `json:"nginx"`
	} `json:"dependencies"`
	ImageNames []string `json:"images"`
}

func (p *Project) validate() error {
	cpath, err := getFilepath(p.Dir, p.Deps.ComposeFile)
	if err != nil {
		return err
	}
	p.Deps.ComposeFile = cpath

	if p.Deps.EnvFile != "" {
		epath, err := getFilepath(p.Dir, p.Deps.EnvFile)
		if err != nil {
			return err
		}
		p.Deps.EnvFile = epath
	} else {
		log.Warn().Msg("no .env file provided, hoping one it's set elsewhere...")
	}

	if p.Deps.NginxFile != "" {
		npath, err := getFilepath(p.Dir, p.Deps.NginxFile)
		if err != nil {
			return err
		}
		p.Deps.NginxFile = npath
	} else {
		log.Warn().Msg("no Nginx conf file provided, Nginx deployment discarded")
	}

	return nil
}

// ProjectFromDir instantiates a new project from a directory path.
//
// The directory path must refers to the path including the `.homeserver` dir not
// the `.homeserver` path itself.
func ProjectFromDir(dir string) (Project, error) {
	var p Project

	dir = filepath.Join(dir, MainDir)
	p.Dir = dir

	content, err := os.ReadFile(filepath.Join(dir, ConfFile))
	if err != nil {
		return p, fmt.Errorf(
			"%w, unable to read conf file=%s, err=%v",
			ErrProjectConfFile,
			ConfFile,
			err,
		)
	}

	if err := json.Unmarshal(content, &p); err != nil {
		return p, fmt.Errorf(
			"%w, unable to parse conf file=%s, err=%v",
			ErrProjectConfFile,
			ConfFile,
			err,
		)
	}

	if err := p.validate(); err != nil {
		return p, fmt.Errorf(
			"%w, unable to validate project, name=%s, dir=%s, err=%v",
			ErrProjectConfFile,
			p.Name,
			p.Dir,
			err,
		)
	}

	return p, nil
}