package store

import (
	"context"
	"database/sql"
	"errors"
	"fmt"

	"gitea.stevedudenhoeffer.com/steve/pansy/internal/domain"
)

// plantingColumns lists plantings columns in the order scanPlanting expects.
// Used unqualified for direct selects; the /full read below qualifies with pl.
const plantingColumns = `id, object_id, plant_id, x_cm, y_cm, radius_cm, count, label,
	planted_at, removed_at, version, created_at, updated_at`

func scanPlanting(s scanner) (*domain.Planting, error) {
	var p domain.Planting
	if err := s.Scan(
		&p.ID, &p.ObjectID, &p.PlantID, &p.XCM, &p.YCM, &p.RadiusCM,
		&p.Count, &p.Label, &p.PlantedAt, &p.RemovedAt,
		&p.Version, &p.CreatedAt, &p.UpdatedAt,
	); err != nil {
		return nil, err
	}
	return &p, nil
}

// ListActivePlantingsForGarden returns every currently-planted plop (removed_at
// IS NULL) across all objects in a garden — the editor's one-shot load. Always a
// non-nil slice. The service fills each row's DerivedCount; this is the raw read.
func (d *DB) ListActivePlantingsForGarden(ctx context.Context, gardenID int64) ([]domain.Planting, error) {
	return queryPlantings(ctx, d.sql,
		`SELECT `+qualifyColumns("pl", plantingColumns)+` FROM plantings pl
		   JOIN garden_objects o ON o.id = pl.object_id
		  WHERE o.garden_id = ? AND pl.removed_at IS NULL
		  ORDER BY pl.id`,
		gardenID)
}

// queryPlantings runs a planting query and scans every row. Like queryObjects it
// drains and closes the cursor before returning, so a transaction caller may
// write afterwards. Always a non-nil slice.
func queryPlantings(ctx context.Context, q queryer, query string, args ...any) ([]domain.Planting, error) {
	rows, err := q.QueryContext(ctx, query, args...)
	if err != nil {
		return nil, fmt.Errorf("store: list plantings: %w", err)
	}
	defer rows.Close()

	plantings := []domain.Planting{}
	for rows.Next() {
		p, err := scanPlanting(rows)
		if err != nil {
			return nil, fmt.Errorf("store: scan planting: %w", err)
		}
		plantings = append(plantings, *p)
	}
	if err := rows.Err(); err != nil {
		return nil, fmt.Errorf("store: iterate plantings: %w", err)
	}
	return plantings, nil
}

// ListActivePlantingsForObject returns an object's currently-planted plops
// (removed_at IS NULL). Always a non-nil slice. Used by FillRegion to avoid
// stacking new plops inside existing ones.
func (d *DB) ListActivePlantingsForObject(ctx context.Context, objectID int64) ([]domain.Planting, error) {
	return queryPlantings(ctx, d.sql,
		`SELECT `+plantingColumns+` FROM plantings WHERE object_id = ? AND removed_at IS NULL ORDER BY id`,
		objectID)
}

// ListPlantingsForObject returns every plop in an object, removed ones included.
// Used when an object is deleted: the FK cascades its plantings away without the
// service seeing them, so they are snapshotted first or the delete would not be
// revertible. Always a non-nil slice.
func (d *DB) ListPlantingsForObject(ctx context.Context, objectID int64) ([]domain.Planting, error) {
	return queryPlantings(ctx, d.sql,
		`SELECT `+plantingColumns+` FROM plantings WHERE object_id = ? ORDER BY id`,
		objectID)
}

// RestorePlanting re-inserts a deleted plop under its ORIGINAL id, preserving
// version and timestamps — the plop counterpart of RestoreObject, and subject to
// the same reasoning. Its parent object must exist again first, or the FK
// rejects it; the revert orders object restores ahead of planting restores.
func (d *DB) RestorePlanting(ctx context.Context, p *domain.Planting) (*domain.Planting, error) {
	restored, err := scanPlanting(d.sql.QueryRowContext(ctx,
		`INSERT INTO plantings
		   (id, object_id, plant_id, x_cm, y_cm, radius_cm, count, label, planted_at, removed_at,
		    version, created_at, updated_at)
		 VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?,
		         strftime('%Y-%m-%dT%H:%M:%SZ', 'now'))
		 RETURNING `+plantingColumns,
		p.ID, p.ObjectID, p.PlantID, p.XCM, p.YCM, p.RadiusCM, p.Count, p.Label,
		p.PlantedAt, p.RemovedAt, p.Version, p.CreatedAt,
	))
	if err != nil {
		return nil, fmt.Errorf("store: restore planting: %w", err)
	}
	return restored, nil
}

// ClearObjectPlantings soft-removes every active plop in an object in one UPDATE
// (sets removed_at=date, bumps version) and returns how many rows it affected.
func (d *DB) ClearObjectPlantings(ctx context.Context, objectID int64, date string) (int, error) {
	res, err := d.sql.ExecContext(ctx,
		`UPDATE plantings
		    SET removed_at = ?, version = version + 1,
		        updated_at = strftime('%Y-%m-%dT%H:%M:%SZ', 'now')
		  WHERE object_id = ? AND removed_at IS NULL`,
		date, objectID,
	)
	if err != nil {
		return 0, fmt.Errorf("store: clear object plantings: %w", err)
	}
	n, err := res.RowsAffected()
	if err != nil {
		return 0, fmt.Errorf("store: clear plantings rows: %w", err)
	}
	return int(n), nil
}

// GetPlanting returns the planting with the given id, or domain.ErrNotFound.
func (d *DB) GetPlanting(ctx context.Context, id int64) (*domain.Planting, error) {
	p, err := scanPlanting(d.sql.QueryRowContext(ctx,
		`SELECT `+plantingColumns+` FROM plantings WHERE id = ?`, id))
	if errors.Is(err, sql.ErrNoRows) {
		return nil, domain.ErrNotFound
	}
	if err != nil {
		return nil, fmt.Errorf("store: get planting: %w", err)
	}
	return p, nil
}

// plantingInsert inserts one plantings row and returns it. Shared by
// CreatePlanting, the CreatePlantings batch and CopyGarden's in-transaction copy
// — with plantingInsertArgs supplying its parameters — so all three stay in step
// with the table. removed_at is never set here: a new plop is active, and "clear
// bed" sets removed_at later via UpdatePlanting.
const plantingInsert = `INSERT INTO plantings (object_id, plant_id, x_cm, y_cm, radius_cm, count, label, planted_at)
	 VALUES (?, ?, ?, ?, ?, ?, ?, ?)
	 RETURNING ` + plantingColumns

// plantingInsertArgs builds plantingInsert's parameters, parenting p to objectID
// (p's own object normally, and the copied object when copying a garden).
func plantingInsertArgs(objectID int64, p *domain.Planting) []any {
	return []any{objectID, p.PlantID, p.XCM, p.YCM, p.RadiusCM, p.Count, p.Label, p.PlantedAt}
}

// CreatePlanting inserts a plop (fields already validated by the service) and
// returns the stored row.
func (d *DB) CreatePlanting(ctx context.Context, p *domain.Planting) (*domain.Planting, error) {
	created, err := scanPlanting(d.sql.QueryRowContext(ctx, plantingInsert, plantingInsertArgs(p.ObjectID, p)...))
	if err != nil {
		return nil, fmt.Errorf("store: insert planting: %w", err)
	}
	return created, nil
}

// CreatePlantings inserts many plops in a single transaction (one commit), for
// bulk fills. Returns the stored rows in order. An empty input is a no-op.
func (d *DB) CreatePlantings(ctx context.Context, plantings []*domain.Planting) ([]domain.Planting, error) {
	if len(plantings) == 0 {
		return []domain.Planting{}, nil
	}
	tx, err := d.sql.BeginTx(ctx, nil)
	if err != nil {
		return nil, fmt.Errorf("store: begin plantings tx: %w", err)
	}
	defer tx.Rollback() //nolint:errcheck // no-op after a successful commit

	out := make([]domain.Planting, 0, len(plantings))
	for _, p := range plantings {
		created, err := scanPlanting(tx.QueryRowContext(ctx, plantingInsert, plantingInsertArgs(p.ObjectID, p)...))
		if err != nil {
			return nil, fmt.Errorf("store: insert planting (batch): %w", err)
		}
		out = append(out, *created)
	}
	if err := tx.Commit(); err != nil {
		return nil, fmt.Errorf("store: commit plantings: %w", err)
	}
	return out, nil
}

// UpdatePlanting applies a version-guarded update of all mutable columns (the
// service merges partial patches first). Returns the updated row, or
// (current row, ErrVersionConflict) / ErrNotFound — the same contract as the
// other mutable resources.
func (d *DB) UpdatePlanting(ctx context.Context, p *domain.Planting) (*domain.Planting, error) {
	updated, err := scanPlanting(d.sql.QueryRowContext(ctx,
		`UPDATE plantings
		    SET plant_id = ?, x_cm = ?, y_cm = ?, radius_cm = ?, count = ?, label = ?,
		        planted_at = ?, removed_at = ?,
		        version = version + 1,
		        updated_at = strftime('%Y-%m-%dT%H:%M:%SZ', 'now')
		  WHERE id = ? AND version = ?
		  RETURNING `+plantingColumns,
		p.PlantID, p.XCM, p.YCM, p.RadiusCM, p.Count, p.Label, p.PlantedAt, p.RemovedAt,
		p.ID, p.Version,
	))
	if errors.Is(err, sql.ErrNoRows) {
		current, gerr := d.GetPlanting(ctx, p.ID)
		if gerr != nil {
			return nil, gerr
		}
		return current, domain.ErrVersionConflict
	}
	if err != nil {
		return nil, fmt.Errorf("store: update planting: %w", err)
	}
	return updated, nil
}

// DeletePlanting hard-deletes a plop (for mistakes; "removed/harvested" flows set
// removed_at instead). Returns domain.ErrNotFound if no row was deleted.
func (d *DB) DeletePlanting(ctx context.Context, id int64) error {
	res, err := d.sql.ExecContext(ctx, `DELETE FROM plantings WHERE id = ?`, id)
	if err != nil {
		return fmt.Errorf("store: delete planting: %w", err)
	}
	n, err := res.RowsAffected()
	if err != nil {
		return fmt.Errorf("store: planting delete rows: %w", err)
	}
	if n == 0 {
		return domain.ErrNotFound
	}
	return nil
}