package database

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

	"git.gocasts.ir/ebhomengo/niki/patientapp/service/analytic"
	"git.gocasts.ir/ebhomengo/niki/patientapp/service/entity"
	errmsg "git.gocasts.ir/ebhomengo/niki/pkg/err_msg"
	richerror "git.gocasts.ir/ebhomengo/niki/pkg/rich_error"
	"git.gocasts.ir/ebhomengo/niki/repository/mysql"
)

type DataBase struct {
	conn *mysql.DB
}

func NewPatientRepo(conn *mysql.DB) *DataBase {
	return &DataBase{
		conn: conn,
	}
}

func (db *DataBase) GetPatients(ctx context.Context, f analytic.PatientFilter) ([]entity.Patient, error) {
	const op = "mysqlpatient.GetPatients"
	limit, offset := clampLimitOffset(f.Limit, f.Offset)

	q := `
SELECT
  p.id,
  p.first_name,
  p.last_name,
  p.date_of_birth,
  p.sex,
  p.phone,

  p.country_id,   
  p.province_id,    
  p.city_id,       
  p.postal_code,
  p.address_line1,
  p.address_line2,

  p.case_status,
  p.referral_source,
  p.assigned_staff_id,
  p.start_date,
  p.end_date
FROM patients p
WHERE p.deleted_at IS NULL
`

	stmt, err := db.conn.PrepareStatement(ctx, mysql.StatementKeyCityGetProvinceIDByID, q)
	if err != nil {
		return nil, richerror.New(op).WithErr(err).
			WithMessage(errmsg.ErrorMsgCantPrepareStatement).WithKind(richerror.KindUnexpected)
	}
	args := make([]any, 0)

	// filters
	if f.Sex != nil {
		q += " AND p.sex = ?"
		args = append(args, string(*f.Sex))
	}
	if f.DOBFrom != nil {
		q += " AND p.date_of_birth >= ?"
		args = append(args, f.DOBFrom.Format("2006-01-02"))
	}
	if f.DOBTo != nil {
		q += " AND p.date_of_birth <= ?"
		args = append(args, f.DOBTo.Format("2006-01-02"))
	}
	if f.Country != nil {
		q += " AND p.country_id = ?"
		args = append(args, *f.Country)
	}
	if f.Province != nil {
		q += " AND p.province_id = ?"
		args = append(args, *f.Province)
	}
	if f.City != nil {
		q += " AND p.city_id = ?"
		args = append(args, *f.City)
	}

	if f.Search != nil && strings.TrimSpace(*f.Search) != "" {
		term := "%" + strings.TrimSpace(*f.Search) + "%"
		q += " AND (p.first_name LIKE ? OR p.last_name LIKE ? OR p.phone LIKE ?)"
		args = append(args, term, term, term)
	}

	q += " ORDER BY p.id DESC LIMIT ? OFFSET ?"
	args = append(args, limit, offset)

	rows, err := stmt.QueryContext(ctx, args...)
	if err != nil {
		return nil, err
	}
	defer rows.Close()

	out := make([]entity.Patient, 0, limit)

	for rows.Next() {
		var p entity.Patient
		var dob sql.NullTime
		var provinceID, cityID uint

		if err := rows.Scan(
			&p.ID,
			&p.FirstName,
			&p.LastName,
			&dob,
			&p.Sex,
			&p.Phone,

			&provinceID,
			&cityID,
			&p.Address.PostalCode,

			&p.CaseStatus,
			&p.ReferralSource,
			&p.AssignedStaffId,
			&p.StartDate,
			&p.EndDate,
		); err != nil {
			return nil, err
		}

		if dob.Valid {
			t := dob.Time
			p.DateOfBirth = &t
		}

		p.Address.ProvinceID = provinceID
		p.Address.CityID = cityID

		out = append(out, p)
	}

	return out, rows.Err()
}

func (db *DataBase) CountPatients(ctx context.Context, f analytic.PatientFilter) (int, error) {
	const op = "mysqlpatient.CountPatients"
	q := `SELECT COUNT(*) FROM patients p WHERE p.deleted_at IS NULL`
	args := make([]any, 0)

	stmt, err := db.conn.PrepareStatement(ctx, mysql.StatementKeyCityGetProvinceIDByID, q)
	if err != nil {
		return 0, richerror.New(op).WithErr(err).
			WithMessage(errmsg.ErrorMsgCantPrepareStatement).WithKind(richerror.KindUnexpected)
	}

	if f.Sex != nil {
		q += " AND p.sex = ?"
		args = append(args, string(*f.Sex))
	}
	if f.DOBFrom != nil {
		q += " AND p.date_of_birth >= ?"
		args = append(args, f.DOBFrom.Format("2006-01-02"))
	}
	if f.DOBTo != nil {
		q += " AND p.date_of_birth <= ?"
		args = append(args, f.DOBTo.Format("2006-01-02"))
	}
	if f.Country != nil {
		q += " AND p.country_id = ?"
		args = append(args, *f.Country)
	}
	if f.Province != nil {
		q += " AND p.province_id = ?"
		args = append(args, *f.Province)
	}
	if f.City != nil {
		q += " AND p.city_id = ?"
		args = append(args, *f.City)
	}

	var total int

	err = stmt.QueryRowContext(ctx, args...).Scan(&total)
	return total, err
}

func (db *DataBase) SummaryByCity(ctx context.Context, provinceID int, f analytic.PatientMapFilter) ([]entity.MapSummaryItem, error) {
	const op = "mysqlpatient.SummaryByCity"
	q := `
SELECT
  c.id AS location_id,
  c.name,
  c.centroid_lat,
  c.centroid_lng,
  COUNT(p.id) AS count
FROM locations c
JOIN patients p ON p.city_id = c.id
WHERE c.level = 'city'
  AND c.parent_id = ?
  AND p.deleted_at IS NULL
`

	stmt, err := db.conn.PrepareStatement(ctx, mysql.StatementKeyCityGetProvinceIDByID, q)
	if err != nil {
		return nil, richerror.New(op).WithErr(err).
			WithMessage(errmsg.ErrorMsgCantPrepareStatement).WithKind(richerror.KindUnexpected)
	}
	args := []any{provinceID}

	if f.Sex != nil {
		q += " AND p.sex = ?"
		args = append(args, string(*f.Sex))
	}
	if f.MinDOB != nil {
		q += " AND p.date_of_birth >= ?"
		args = append(args, f.MinDOB.Format("2006-01-02"))
	}
	if f.MaxDOB != nil {
		q += " AND p.date_of_birth <= ?"
		args = append(args, f.MaxDOB.Format("2006-01-02"))
	}
	if f.Search != nil && strings.TrimSpace(*f.Search) != "" {
		term := "%" + strings.TrimSpace(*f.Search) + "%"
		q += " AND (p.first_name LIKE ? OR p.last_name LIKE ? OR p.phone LIKE ?)"
		args = append(args, term, term, term)
	}

	q += ` GROUP BY c.id, c.name, c.centroid_lat, c.centroid_lng
	       ORDER BY count DESC`

	rows, err := stmt.QueryContext(ctx, args...)
	if err != nil {
		return nil, err
	}
	defer rows.Close()

	var out []entity.MapSummaryItem
	for rows.Next() {
		var it entity.MapSummaryItem
		if err := rows.Scan(&it.LocationID, &it.Name, &it.CentroidLat, &it.CentroidLng, &it.Count); err != nil {
			return nil, err
		}
		out = append(out, it)
	}
	return out, rows.Err()
}

func (db *DataBase) SummaryByProvince(ctx context.Context, countryID int, f analytic.PatientMapFilter) ([]entity.MapSummaryItem, error) {
	const op = "mysqlpatient.SummaryByProvince"

	q := `
SELECT
  prov.id AS location_id,
  prov.name,
  prov.centroid_lat,
  prov.centroid_lng,
  COUNT(p.id) AS count
FROM patients p
JOIN locations city ON city.id = p.city_id AND city.level = 'city'
JOIN locations prov ON prov.id = city.parent_id AND prov.level = 'province'
WHERE prov.parent_id = ?
  AND p.deleted_at IS NULL
`

	stmt, err := db.conn.PrepareStatement(ctx, mysql.StatementKeyCityGetProvinceIDByID, q)
	if err != nil {
		return nil, richerror.New(op).WithErr(err).
			WithMessage(errmsg.ErrorMsgCantPrepareStatement).WithKind(richerror.KindUnexpected)
	}

	args := []any{countryID}

	if f.Sex != nil {
		q += " AND p.sex = ?"
		args = append(args, string(*f.Sex))
	}
	if f.MinDOB != nil {
		q += " AND p.date_of_birth >= ?"
		args = append(args, f.MinDOB.Format("2006-01-02"))
	}
	if f.MaxDOB != nil {
		q += " AND p.date_of_birth <= ?"
		args = append(args, f.MaxDOB.Format("2006-01-02"))
	}

	q += ` GROUP BY prov.id, prov.name, prov.centroid_lat, prov.centroid_lng
	       ORDER BY count DESC`

	rows, err := stmt.QueryContext(ctx, args...)
	if err != nil {
		return nil, err
	}
	defer rows.Close()

	var out []entity.MapSummaryItem
	for rows.Next() {
		var it entity.MapSummaryItem
		if err := rows.Scan(&it.LocationID, &it.Name, &it.CentroidLat, &it.CentroidLng, &it.Count); err != nil {
			return nil, err
		}
		out = append(out, it)
	}
	return out, rows.Err()
}