package restic

import (
	"encoding/json"
	"fmt"
	"github.com/rs/zerolog/log"
	"os/exec"
	"time"
)

type ResticSnapshot struct {
	Time  time.Time `json:"time"` // format 2023-03-01T16:15:34.111513+01:00
	Tree  string    `json:"tree"`
	Paths []string  `json:"paths"`
	Id    string    `json:"short_id"`
}

func (rs ResticSnapshot) ShortTime() string {
	return rs.Time.Format(ShortTimeFormat)
}

type Wrapper struct {
	LatestSnapshots []ResticSnapshot
	mountCommand    *exec.Cmd
}

func (w *Wrapper) HasSnapshots() bool {
	return len(w.LatestSnapshots) > 0
}

func (w *Wrapper) LastSnapshot() ResticSnapshot {
	if !w.HasSnapshots() {
		return ResticSnapshot{
			Id:   "(no snapshots yet)",
			Time: time.Time{},
		}
	}
	return w.LatestSnapshots[len(w.LatestSnapshots)-1]
}

func resticCmd(args ...string) *exec.Cmd {
	cmd := exec.Command("restic", args...)
	log.Debug().Msg(cmd.String())
	return cmd
}

/*
Expected JSON format:
[

	{
	  "time": "2023-03-01T16:15:34.111513+01:00",
	  "tree": "d603aa4c6ce2bdef784dbdcd36461970d7f0cc8083d31f46d23cdb9bef172f0a",
	  "paths": [
	    "/Users/wgroeneveld"
	  ],
	  "hostname": "Wouters-M1-Air.local",
	  "username": "wgroeneveld",
	  "uid": 501,
	  "gid": 20,
	  "id": "31ae2a213c5750c4f86ebe8a8e989a5d4de2963c911e7513f47ca227723a0d95",
	  "short_id": "31ae2a21"
	}

]
*/
func (w *Wrapper) UpdateLatestSnapshots(c *Config) error {
	cmd := resticCmd("--json", "--password-file", c.PasswordFile(), "-r", c.Repository, "snapshots")
	out, err := cmd.CombinedOutput()
	if err != nil {
		return fmt.Errorf("restic snapshots cmd: %s: %w", string(out), err)
	}

	err = json.Unmarshal(out, &w.LatestSnapshots)
	if err != nil {
		return err
	}

	log.Debug().Any("snapshots", w.LatestSnapshots).Msg("update")
	return nil
}

func (w *Wrapper) MountBackups(c *Config) error {
	c.CreateMountDirIfDoesntExist()
	if w.mountCommand != nil && w.mountCommand.Process != nil {
		// could be killed or terminted due to manual unmount, ignore errors and retry anyway
		w.mountCommand.Process.Kill()
	}

	// Open the folder first: MacFuse could take a second; results in occasional weird errors otherwise.
	openFolder(c.MountDir())

	w.mountCommand = resticCmd("--password-file", c.PasswordFile(), "-r", c.Repository, "mount", c.MountDir())
	err := w.mountCommand.Start() // restic's mount is a blocking call
	if err != nil {
		return fmt.Errorf("restic mount cmd: %w", err)
	}
	return nil
}

func openFolder(folder string) error {
	cmd := exec.Command("open", folder)
	out, err := cmd.CombinedOutput()
	if err != nil {
		return fmt.Errorf("open mount dir: %s: %w", string(out), err)
	}
	return nil
}

func (w *Wrapper) Backup(c *Config) error {
	cmd := resticCmd("--json", "--password-file", c.PasswordFile(), "-r", c.Repository, "--exclude-file", c.ExcludeFile(), "backup", c.Backup)
	out, err := cmd.CombinedOutput()
	if err != nil {
		return fmt.Errorf("restic backup cmd: %s: %w", string(out), err)
	}
	log.Debug().Str("out", string(out)).Msg("backup")
	return nil
}