package hrana

import (
	"github.com/tursodatabase/libsql-client-go/libsql/internal/http/shared"
)

type StreamRequest struct {
	Type  string  `json:"type"`
	Stmt  *Stmt   `json:"stmt,omitempty"`
	Batch *Batch  `json:"batch,omitempty"`
	Sql   *string `json:"sql,omitempty"`
	SqlId *int32  `json:"sql_id,omitempty"`
}

func CloseStream() StreamRequest {
	return StreamRequest{Type: "close"}
}

func ExecuteStream(sql string, params *shared.Params, wantRows bool) (*StreamRequest, error) {
	stmt := &Stmt{
		Sql:      &sql,
		WantRows: wantRows,
	}
	if params != nil {
		if err := stmt.AddArgs(*params); err != nil {
			return nil, err
		}
	}
	return &StreamRequest{Type: "execute", Stmt: stmt}, nil
}

func ExecuteStoredStream(sqlId int32, params shared.Params, wantRows bool) (*StreamRequest, error) {
	stmt := &Stmt{
		SqlId:    &sqlId,
		WantRows: wantRows,
	}
	if err := stmt.AddArgs(params); err != nil {
		return nil, err
	}
	return &StreamRequest{Type: "execute", Stmt: stmt}, nil
}

func BatchStream(sqls []string, params []shared.Params, wantRows bool, transactional bool) (*StreamRequest, error) {
	size := len(sqls)
	if transactional {
		size += 1
	}
	batch := &Batch{Steps: make([]BatchStep, 0, size)}
	addArgs := len(params) > 0
	for idx, sql := range sqls {
		s := sql
		stmt := &Stmt{
			Sql:      &s,
			WantRows: wantRows,
		}
		if addArgs {
			if err := stmt.AddArgs(params[idx]); err != nil {
				return nil, err
			}
		}
		var condition *BatchCondition
		if transactional {
			if idx > 0 {
				prev_idx := int32(idx - 1)
				condition = &BatchCondition{
					Type: "ok",
					Step: &prev_idx,
				}
			}
		}
		batch.Add(*stmt, condition)
	}
	if transactional {
		rollback := "ROLLBACK"
		last_idx := int32(len(sqls) - 1)
		batch.Add(Stmt{Sql: &rollback, WantRows: false},
			&BatchCondition{Type: "not", Cond: &BatchCondition{Type: "ok", Step: &last_idx}})
	}
	return &StreamRequest{Type: "batch", Batch: batch}, nil
}

func StoreSqlStream(sql string, sqlId int32) StreamRequest {
	return StreamRequest{Type: "store_sql", Sql: &sql, SqlId: &sqlId}
}

func CloseStoredSqlStream(sqlId int32) StreamRequest {
	return StreamRequest{Type: "close_sql", SqlId: &sqlId}
}