package psql

import (
	"fmt"
	"log"
	"os"
	"os/exec"
	"path"
	"path/filepath"
	"runtime"

	"baal.ar76.eu/x/pub/multisql/cfg"
)

type Instance struct {
	outdir   string
	scripts  []string
	passfile string
	psqlExe  string
	conn     cfg.Connection
	verbose  bool
}

type Result struct {
	Script string
	Err    error
}

func Create(passfile string, outdir string, scripts []string, conn cfg.Connection, psqlExe string, verbose bool) (instnace Instance) {

	instnace = Instance{
		outdir:   outdir,
		scripts:  scripts,
		passfile: passfile,
		conn:     conn,
		psqlExe:  psqlExe,
		verbose:  verbose,
	}
	return instnace
}

func (self Instance) Exec(result chan<- Result) {
	absPassFile := ""
	if self.passfile != "" {
		var err error
		absPassFile, err = filepath.Abs(self.passfile)
		if err != nil {
			result <- Result{
				Script: "*",
				Err:    fmt.Errorf("problem ze zbudowaniem ściężki do pliku haseł: %w", err),
			}
			return
		}
	}
	connString := fmt.Sprintf("host=%s port=%d dbname=%s user=%s", self.conn.Host, self.conn.Port, self.conn.DbName, self.conn.User)

	for _, scr := range self.scripts {
		srcName := path.Base(scr)
		outdir := path.Join(self.outdir, srcName)
		err := os.Mkdir(outdir, 0o775)
		if err != nil {
			result <- Result{
				Script: scr,
				Err:    err,
			}
			continue
		}
		err = self.cmdPsql(outdir, connString, scr, absPassFile)
		result <- Result{
			Script: scr,
			Err:    err,
		}
	}
	close(result)
}

func (self Instance) cmdPsql(outdir string, connString string, script string, passfile string) error {
	absScript, err := filepath.Abs(script)
	if err != nil {
		return fmt.Errorf("problem ze zbudowaniem ściezki do skryptu: %w", err)
	}
	psqlExe := "psql"
	if runtime.GOOS == "windows" {
		psqlExe = "psql.exe"
	}
	if self.psqlExe != "" {
		psqlExe = self.psqlExe
	}
	stdoutFile := path.Join(outdir, "stdout.txt")
	stderrFile := path.Join(outdir, "stderr.txt")
	logFile := "log.txt"

	fhOut, err := os.Create(stdoutFile)
	if err != nil {
		return fmt.Errorf("Problem utworzenie pliku wyników: %v", err)
	}
	defer fhOut.Close()

	fhErr, err := os.Create(stderrFile)
	if err != nil {
		return fmt.Errorf("Problem utworzenie pliku błędów: %v", err)
	}
	defer fhErr.Close()

	cmd := exec.Command(psqlExe,
		"-w",
		"-f", absScript,
		"-L", logFile,
		connString,
	)
	cmd.Stderr = fhErr
	cmd.Stdout = fhOut
	cmd.Dir = outdir

	if passfile != "" {
		env := os.Environ()
		env = append(env, "PGPASSFILE=" + passfile)
		cmd.Env = env
	}


	if self.verbose {
		log.Printf("Uruchamiam %s", cmd.String())
	}
	err = cmd.Run()
	if err != nil {
		return fmt.Errorf("Błąd uruchamiania psql: %v", err)
	}
	return nil
}