package db

import (
	"context"
	"errors"
	"fmt"

	"management/internal/pkg/config"

	"github.com/jackc/pgconn"
	"github.com/jackc/pgx/v5"
	"github.com/jackc/pgx/v5/pgxpool"
)

// ****************** conn ******************

func newDsn(conf config.DB) string {
	return fmt.Sprintf("postgresql://%s:%s@%s:%d/%s?sslmode=disable",
		conf.Username,
		conf.Password,
		conf.Host,
		conf.Port,
		conf.DBName)
}

// ****************** errors ******************

const (
	foreignKeyViolation = "23503"
	uniqueViolation     = "23505"
)

// var ErrUniqueViolation = &pgconn.PgError{
// 	Code: UniqueViolation,
// }

func ErrorCode(err error) string {
	var pgErr *pgconn.PgError
	if errors.As(err, &pgErr) {
		return pgErr.Code
	}
	return ""
}

// ****************** store ******************
var Engine Store

// Store defines all functions to execute db queries and transactions
type Store interface {
	Querier
	ExecTx(context.Context, func(*Queries) error) error

	Pool() *pgxpool.Pool

	SysDepartmentRebuildPath(ctx context.Context) error
	SysRoleRebuildPath(ctx context.Context) error
	CategoryRebuildPath(ctx context.Context) error

	ListCustomerCondition(ctx context.Context, arg *ListCustomerConditionParam) ([]*CustomerView, int64, error)
	ListProjectCondition(ctx context.Context, arg *ListProjectConditionParam) ([]*ProjectView, int64, error)
	ListBudgetCondition(ctx context.Context, arg *ListBudgetConditionParam) ([]*BudgetView, int64, error)
	ListIncomeCondition(ctx context.Context, arg *ListIncomeConditionParam) ([]*IncomeView, int64, error)
	ListExpenseCondition(ctx context.Context, arg *ListExpenseConditionParam) ([]*ExpenseView, int64, error)
}

// SQLStore provides all functions to execute SQL queries and transactions
type SQLStore struct {
	connPool *pgxpool.Pool
	*Queries
}

func NewIStore(ctx context.Context, conf config.DB) (Store, error) {
	pool, err := pgxpool.New(ctx, newDsn(conf))
	if err != nil {
		return nil, err
	}

	err = pool.Ping(ctx)
	if err != nil {
		return nil, err
	}

	return &SQLStore{
		connPool: pool,
		Queries:  New(pool),
	}, nil
}

// NewStore creates a new store
func NewStore(ctx context.Context) error {
	pool, err := pgxpool.New(ctx, newDsn(config.File.DB))
	if err != nil {
		return err
	}

	err = pool.Ping(ctx)
	if err != nil {
		return err
	}

	Engine = &SQLStore{
		connPool: pool,
		Queries:  New(pool),
	}

	return nil
}

func (store *SQLStore) Pool() *pgxpool.Pool {
	return store.connPool
}

func IsUniqueViolation(err error) bool {
	return ErrorCode(err) == uniqueViolation
}

func IsForeignKeyViolation(err error) bool {
	return ErrorCode(err) == foreignKeyViolation
}

func IsNoRows(err error) bool {
	return errors.Is(err, pgx.ErrNoRows)
}

func (store *SQLStore) ExecTx(ctx context.Context, fn func(*Queries) error) error {
	tx, err := store.connPool.Begin(ctx)
	if err != nil {
		return err
	}

	q := New(tx)
	err = fn(q)
	if err != nil {
		if rbErr := tx.Rollback(ctx); rbErr != nil {
			return fmt.Errorf("tx err: %v, rb err: %v", err, rbErr)
		}
		return err
	}

	return tx.Commit(ctx)
}

func (store *SQLStore) SysDepartmentRebuildPath(ctx context.Context) error {
	query := `
		UPDATE sys_department AS tm
		SET parent_path = (SELECT ',' || string_agg(cast(t.parent_id AS VARCHAR), ',') || ','
						FROM (WITH RECURSIVE temp (id, parent_id) AS (SELECT id, tm.parent_id
																		FROM sys_department
																		WHERE id = tm.id
																		UNION ALL
																		SELECT sys_department.id, sys_department.parent_id
																		FROM sys_department,
																			temp
																		WHERE sys_department.id = temp.parent_id)
								SELECT id, parent_id
								FROM temp
								ORDER BY id) AS t)
		WHERE tm.status = 0 ;`
	_, err := store.db.Exec(ctx, query)
	return err
}

func (store *SQLStore) SysRoleRebuildPath(ctx context.Context) error {
	query := `
		UPDATE sys_role AS tm
		SET parent_path = (SELECT ',' || string_agg(cast(t.parent_id AS VARCHAR), ',') || ','
						FROM (WITH RECURSIVE temp (id, parent_id) AS (SELECT id, tm.parent_id
																		FROM sys_role
																		WHERE id = tm.id
																		UNION ALL
																		SELECT sys_role.id, sys_role.parent_id
																		FROM sys_role,
																			temp
																		WHERE sys_role.id = temp.parent_id)
								SELECT id, parent_id
								FROM temp
								ORDER BY id) AS t)
		WHERE tm.status = 0;`
	_, err := store.db.Exec(ctx, query)
	return err
}

func (store *SQLStore) CategoryRebuildPath(ctx context.Context) error {
	query := `
		UPDATE categories AS tm
		SET parent_path = (SELECT ',' || string_agg(cast(t.parent_id AS VARCHAR), ',') || ','
						FROM (WITH RECURSIVE temp (id, parent_id) AS (SELECT id, tm.parent_id
																		FROM categories
																		WHERE id = tm.id
																		UNION ALL
																		SELECT categories.id, categories.parent_id
																		FROM categories,
																			temp
																		WHERE categories.id = temp.parent_id)
								SELECT id, parent_id
								FROM temp
								ORDER BY id) AS t)
		WHERE tm.status = 0;`
	_, err := store.db.Exec(ctx, query)
	return err
}