package fstore

import (
	"log"
	"os"
	"path/filepath"

	"git.crumpington.com/public/jldb/lib/errs"
	"git.crumpington.com/public/jldb/lib/idgen"
)

func (s *Store) applyStoreFromReader(cmd command) error {
	tmpPath := tempFilePath(s.tmpDir, idgen.Next())

	f, err := os.Create(tmpPath)
	if err != nil {
		return errs.IO.WithErr(err)
	}
	defer f.Close()

	n, err := f.ReadFrom(cmd.File)
	if err != nil {
		return errs.IO.WithErr(err)
	}
	if n != cmd.FileSize {
		return errs.IO.WithMsg("expected to %d bytes, but got %d", cmd.FileSize, n)
	}

	if err := f.Sync(); err != nil {
		return errs.IO.WithErr(err)
	}

	fullPath := filepath.Join(s.filesRoot, cmd.Path)

	if err := os.MkdirAll(filepath.Dir(fullPath), 0700); err != nil {
		return errs.IO.WithErr(err)
	}

	if err := os.Rename(tmpPath, fullPath); err != nil {
		return errs.IO.WithErr(err)
	}

	return nil
}

func (s *Store) applyStoreFromTempID(cmd command) error {
	tmpPath := tempFilePath(s.tmpDir, cmd.TempID)
	fullPath := filepath.Join(s.filesRoot, cmd.Path)

	info, err := os.Stat(tmpPath)
	if err != nil || info.Size() != cmd.FileSize {
		log.Printf("[STORE] Primary falling back on reader copy: %v", err)
		return s.applyStoreFromReader(cmd)
	}

	if err := os.MkdirAll(filepath.Dir(fullPath), 0700); err != nil {
		return errs.IO.WithErr(err)
	}

	if err := os.Rename(tmpPath, fullPath); err != nil {
		return errs.IO.WithErr(err)
	}
	return nil
}

func (s *Store) applyRemove(cmd command) error {
	finalPath := filepath.Join(s.filesRoot, cmd.Path)
	if err := os.Remove(finalPath); err != nil {
		if !os.IsNotExist(err) {
			return errs.IO.WithErr(err)
		}
	}

	parent := filepath.Dir(finalPath)
	for parent != s.filesRoot {
		if err := os.Remove(parent); err != nil {
			return nil
		}
		parent = filepath.Dir(parent)
	}

	return nil
}