package models

import (
	"encoding/json"
	"errors"
	"fmt"
	"io/fs"
	"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 getFileInfo(baseDir, filePath string) (string, fs.FileInfo, error) {
	var fInf fs.FileInfo

	if !filepath.IsAbs(filePath) {
		filePath = filepath.Join(baseDir, filePath)

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

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

	return filePath, fInf, nil
}

// Project handles the details and file informations of your project.
type Project struct {
	Name       string `json:"name"`
	Dir        string
	ImageNames []string `json:"images"`
	Deps       struct {
		EnvFile     string `json:"env"`
		EnvFileInfo fs.FileInfo

		ComposeFile     string `json:"compose"`
		ComposeFileInfo fs.FileInfo

		NginxFile     string `json:"nginx"`
		NginxFileInfo fs.FileInfo
	} `json:"dependencies"`
}

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

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

	npath, nfs, err := getFileInfo(p.Dir, p.Deps.NginxFile)
	if err != nil {
		return err
	}
	p.Deps.NginxFileInfo = nfs
	p.Deps.NginxFile = npath

	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
}