package postgres

import (
	"database/sql"
	"gardomatic.kleiax.de/internal/storage"
)

// CareInstructionModel implements storage.CareInstructionModelInterface for
// PostgreSQL and scopes every lookup through the owning garden.
type CareInstructionModel struct{ DB *sql.DB }

const careInstructionColumns = `ci.id, ci.species_id, ci.text, ci.status, ci.created_by, ci.updated_by, ci.created_at, ci.updated_at, ci.version`

func scanCareInstruction(s scanner) (storage.CareInstruction, error) {
	var item storage.CareInstruction
	err := s.Scan(&item.ID, &item.SpeciesID, &item.Text, &item.Status, &item.CreatedBy, &item.UpdatedBy, &item.CreatedAt, &item.UpdatedAt, &item.Version)
	return item, err
}

// Insert creates a care instruction.
func (m CareInstructionModel) Insert(item storage.CareInstruction) (storage.CareInstruction, error) {
	ctx, cancel := contextWithTimeout()
	defer cancel()
	err := m.DB.QueryRowContext(ctx, `INSERT INTO care_instructions(species_id,text,status,created_by,updated_by) VALUES($1,$2,$3,$4,$5) RETURNING id,created_at,updated_at,version`, item.SpeciesID, item.Text, item.Status, item.CreatedBy, item.UpdatedBy).Scan(&item.ID, &item.CreatedAt, &item.UpdatedAt, &item.Version)
	return item, recordError(err)
}

// Get returns a care instruction within its garden and species.
func (m CareInstructionModel) Get(gardenID, speciesID, id int) (storage.CareInstruction, error) {
	ctx, cancel := contextWithTimeout()
	defer cancel()
	return scanCareInstruction(m.DB.QueryRowContext(ctx, `SELECT `+careInstructionColumns+` FROM care_instructions ci JOIN species s ON s.id=ci.species_id WHERE ci.id=$1 AND ci.species_id=$2 AND (s.garden_id IS NULL OR s.garden_id=$3)`, id, speciesID, gardenID))
}

// GetAllForSpecies lists care instructions for a species visible in a garden.
func (m CareInstructionModel) GetAllForSpecies(gardenID, speciesID int) ([]storage.CareInstruction, error) {
	ctx, cancel := contextWithTimeout()
	defer cancel()
	rows, err := m.DB.QueryContext(ctx, `SELECT `+careInstructionColumns+` FROM care_instructions ci JOIN species s ON s.id=ci.species_id WHERE ci.species_id=$1 AND (s.garden_id IS NULL OR s.garden_id=$2) ORDER BY ci.id`, speciesID, gardenID)
	if err != nil {
		return nil, err
	}
	defer rows.Close()
	items := []storage.CareInstruction{}
	for rows.Next() {
		item, e := scanCareInstruction(rows)
		if e != nil {
			return nil, e
		}
		items = append(items, item)
	}
	return items, rows.Err()
}

// Update changes a care instruction using optimistic locking.
func (m CareInstructionModel) Update(gardenID int, item storage.CareInstruction) (storage.CareInstruction, error) {
	ctx, cancel := contextWithTimeout()
	defer cancel()
	err := m.DB.QueryRowContext(ctx, `UPDATE care_instructions ci SET text=$1,status=$2,updated_by=$3,updated_at=now(),version=ci.version+1 FROM species s WHERE ci.species_id=s.id AND ci.id=$4 AND ci.version=$5 AND (s.garden_id IS NULL OR s.garden_id=$6) RETURNING ci.updated_at,ci.version`, item.Text, item.Status, item.UpdatedBy, item.ID, item.Version, gardenID).Scan(&item.UpdatedAt, &item.Version)
	if err == sql.ErrNoRows {
		return storage.CareInstruction{}, storage.ErrEditConflict
	}
	return item, recordError(err)
}

// Delete removes a care instruction within its garden and species.
func (m CareInstructionModel) Delete(gardenID, speciesID, id int) error {
	ctx, cancel := contextWithTimeout()
	defer cancel()
	result, err := m.DB.ExecContext(ctx, `DELETE FROM care_instructions ci USING species s WHERE ci.species_id=s.id AND ci.species_id=$1 AND ci.id=$2 AND (s.garden_id IS NULL OR s.garden_id=$3)`, speciesID, id, gardenID)
	if err != nil {
		return err
	}
	n, err := result.RowsAffected()
	if err != nil {
		return err
	}
	if n == 0 {
		return storage.ErrRecordNotFound
	}
	return nil
}