package diyanetcitydb

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

	"github.com/doug-martin/goqu/v9"

	"prayertimes/pkg/prayer"
)

var ErrLocationNotFound = errors.New("location not found")

type Provider struct {
	db *goqu.Database
}

func New(conn *sql.DB) Provider {
	return Provider{db: goqu.New("sqlite3", conn)}
}

type locationRow struct {
	ID        int     `db:"id"`
	Country   string  `db:"country"`
	City      string  `db:"city"`
	Region    string  `db:"region"`
	Latitude  float64 `db:"latitude"`
	Longitude float64 `db:"longitude"`
	Timezone  string  `db:"timezone"`
}

func (p Provider) SearchLocations(ctx context.Context, query string) ([]prayer.LegacyLocation, error) {
	query = strings.TrimSpace(query)
	if query == "" {
		return nil, nil
	}

	pattern := "%" + query + "%"

	q := p.db.
		From("diyanet_cities").
		Select(
			goqu.I("id"),
			goqu.I("country"),
			goqu.I("city"),
			goqu.COALESCE(goqu.I("region"), "").As("region"),
			goqu.I("latitude"),
			goqu.I("longitude"),
			goqu.COALESCE(goqu.I("timezone"), "").As("timezone"),
		).
		Where(
			goqu.Or(
				goqu.L("country LIKE ? COLLATE NOCASE", pattern),
				goqu.L("city LIKE ? COLLATE NOCASE", pattern),
				goqu.L("COALESCE(region, '') LIKE ? COLLATE NOCASE", pattern),
			),
		).
		Order(
			goqu.I("country").Asc(),
			goqu.I("city").Asc(),
			goqu.I("region").Asc(),
			goqu.I("id").Asc(),
		).
		Limit(100)

	rows := make([]locationRow, 0)
	if err := q.ScanStructsContext(ctx, &rows); err != nil {
		return nil, fmt.Errorf("failed to query diyanet locations: %w", err)
	}

	locations := make([]prayer.LegacyLocation, 0, len(rows))
	for _, row := range rows {
		locations = append(locations, prayer.LegacyLocation{
			ID:        row.ID,
			Country:   row.Country,
			City:      row.City,
			Region:    row.Region,
			Latitude:  row.Latitude,
			Longitude: row.Longitude,
			Timezone:  row.Timezone,
		})
	}

	return locations, nil
}

func (p Provider) GetLocationByID(ctx context.Context, id int) (prayer.LegacyLocation, error) {
	q := p.db.
		From("diyanet_cities").
		Select(
			goqu.I("id"),
			goqu.I("country"),
			goqu.I("city"),
			goqu.COALESCE(goqu.I("region"), "").As("region"),
			goqu.I("latitude"),
			goqu.I("longitude"),
			goqu.COALESCE(goqu.I("timezone"), "").As("timezone"),
		).
		Where(goqu.I("id").Eq(id)).
		Limit(1)

	var rows []locationRow
	if err := q.ScanStructsContext(ctx, &rows); err != nil {
		return prayer.LegacyLocation{}, fmt.Errorf("failed to query location by id: %w", err)
	}
	if len(rows) == 0 {
		return prayer.LegacyLocation{}, ErrLocationNotFound
	}

	row := rows[0]
	location := prayer.LegacyLocation{
		ID:        row.ID,
		Country:   row.Country,
		City:      row.City,
		Region:    row.Region,
		Latitude:  row.Latitude,
		Longitude: row.Longitude,
		Timezone:  row.Timezone,
	}

	return location, nil
}