package sqimple

import (
	"context"
	"database/sql"
	"fmt"
	"slices"
	"strings"
)

// https://www.sqlite.org/lang_delete.html
type InsertStatement struct {
	Ctx context.Context
	DB  *sql.DB

	table InsertTable
	or    string

	columns []string
	values  []Values

	selectValues *SelectQuery
}

func (s *InsertStatement) Args() []any {
	if s.selectValues != nil {
		return s.selectValues.Args()
	}

	args := []any{}
	for _, row := range s.values {
		for _, column := range s.columns {
			args = append(args, row[column])
		}
	}

	return args
}

func (s *InsertStatement) Exec() (sql.Result, error) {
	if s.DB != nil {
		if s.Ctx != nil {
			return s.DB.ExecContext(s.Ctx, s.String(), s.Args()...)
		}

		return s.DB.Exec(s.String(), s.Args()...)
	}

	return nil, ErrNoDatabase
}

func (s *InsertStatement) IsValid() bool {
	if !s.table.IsValid() {
		return false
	}

	return false
}

func (s *InsertStatement) Columns(columns ...string) *InsertStatement {
	if s.columns == nil {
		s.columns = []string{}
	}

	for _, column := range columns {
		if !slices.Contains(s.columns, column) {
			s.columns = append(s.columns, columns...)
		}
	}

	return s
}

func (s *InsertStatement) Or(or string) *InsertStatement {
	s.or = or
	return s
}

func (s *InsertStatement) Select(q *SelectQuery) *InsertStatement {
	s.selectValues = q

	return s
}

func (s *InsertStatement) String() string {
	strs := []string{"insert"}

	if s.or != "" {
		strs = append(strs, "or", s.or)
	}

	strs = append(strs, s.table.String())

	if len(s.columns) > 0 {
		strs = append(strs, fmt.Sprintf("(%s)", strings.Join(s.columns, ", ")))
	}

	if s.selectValues != nil {
		strs = append(strs, s.selectValues.String())
	} else {
		strs = append(strs, "values")

		valueStrs := []string{}
		for range s.values {
			marks := []string{}
			for range s.columns {
				marks = append(marks, "?")
			}

			valueStrs = append(valueStrs, fmt.Sprintf("(%s)", strings.Join(marks, ", ")))
		}

		strs = append(strs, strings.Join(valueStrs, ", "))
	}

	return strings.Join(strs, " ")
}

func (s *InsertStatement) Values(values ...Values) *InsertStatement {
	if s.values == nil {
		s.values = []Values{}
	}

	for _, row := range values {
		s.values = append(s.values, row)
	}

	return s
}

func Insert(into string) *InsertStatement {
	s := &InsertStatement{
		table: Into(into),
	}

	return s
}