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use std::rc::Rc;
use crate::common::Validation;
use crate::error::Result;
use crate::json::Appliable;
use crate::operation::{Operation, OperationComponent, Operator};
use crate::path::{Path, PathElement};
use crate::sub_type::SubTypeFunctionsHolder;
fn is_equivalent_to_noop(op: &OperationComponent) -> bool {
match &op.operator {
Operator::Noop() => true,
Operator::SubType(_, _, _) => false,
Operator::ListInsert(_)
| Operator::ListDelete(_)
| Operator::ObjectInsert(_)
| Operator::ObjectDelete(_) => false,
Operator::ListReplace(new_v, old_v) | Operator::ObjectReplace(new_v, old_v) => {
new_v.eq(old_v)
}
Operator::ListMove(lm) => op
.path
.last()
.map(|p| p == &PathElement::Index(*lm))
.unwrap_or(false),
}
}
fn is_same_operand(op_a: &OperationComponent, op_b: &OperationComponent) -> bool {
if let Operator::SubType(_, _, _) = op_a.operator {
return false;
}
if let Operator::SubType(_, _, _) = op_b.operator {
return false;
}
op_a.path.len() == op_b.path.len()
}
#[derive(PartialEq)]
pub enum TransformSide {
LEFT,
RIGHT,
}
pub struct Transformer {}
impl Transformer {
pub fn new(_: Rc<SubTypeFunctionsHolder>) -> Transformer {
Transformer {}
}
pub fn transform(
&self,
operation: &Operation,
base_operation: &Operation,
) -> Result<(Operation, Operation)> {
if base_operation.is_empty() {
return Ok((operation.clone(), Operation::empty_operation()));
}
operation.validates()?;
base_operation.validates()?;
if operation.len() == 1 && base_operation.len() == 1 {
let a = self.transform_component(
operation.get(0).unwrap().clone(),
base_operation.get(0).unwrap(),
TransformSide::LEFT,
)?;
let b = self.transform_component(
base_operation.get(0).unwrap().clone(),
operation.get(0).unwrap(),
TransformSide::RIGHT,
)?;
return Ok((a.into(), b.into()));
}
self.transform_matrix(operation.clone(), base_operation.clone())
}
fn transform_matrix(
&self,
operation: Operation,
base_operation: Operation,
) -> Result<(Operation, Operation)> {
if operation.is_empty() || base_operation.is_empty() {
return Ok((operation, base_operation));
}
let mut out_b = vec![];
let mut ops = operation;
for base_op in base_operation {
let (a, b) = self.transform_multi(ops, base_op)?;
ops = a;
if let Some(o) = b {
out_b.push(o);
}
}
Ok((ops, out_b.into()))
}
fn transform_multi(
&self,
operation: Operation,
base_op: OperationComponent,
) -> Result<(Operation, Option<OperationComponent>)> {
let mut out: Vec<OperationComponent> = vec![];
let mut base = base_op.not_noop();
for op in operation {
match base {
Some(b) => {
let backup = op.clone();
let mut a = self.transform_component(op, &b, TransformSide::LEFT)?;
let mut b = self.transform_component(b, &backup, TransformSide::RIGHT)?;
assert!(b.len() == 1);
base = b.pop();
out.append(&mut a);
}
None => {
out.push(op.clone());
continue;
}
}
}
Ok((out.into(), base))
}
fn transform_component(
&self,
new_op: OperationComponent,
base_op: &OperationComponent,
side: TransformSide,
) -> Result<Vec<OperationComponent>> {
let mut new_op = new_op;
if is_equivalent_to_noop(&new_op) || is_equivalent_to_noop(base_op) {
return Ok(vec![new_op]);
}
let max_common_path = base_op.path.max_common_path(&new_op.path);
let new_operate_path_len = new_op.operate_path_len();
let base_operate_path_len = base_op.operate_path_len();
if max_common_path.len() < new_operate_path_len
&& max_common_path.len() < base_operate_path_len
{
// common path must be equal to new_op's or base_op's operate path
// or base_op and new_op is operating on orthogonal value
// they don't need transform
return Ok(vec![new_op]);
}
// such as:
// new_op, base_op
// [p1,p2,p3], [p1,p2,p4,p5]
// [p1,p2,p3], [p1,p2,p3,p5]
if base_operate_path_len > new_operate_path_len {
// if base_op's path is longger and contains new_op's path, new_op should include base_op's effect
if new_op.path.is_prefix_of(&base_op.path) {
self.consume(&mut new_op, &max_common_path, base_op)?;
}
return Ok(vec![new_op]);
}
// from here, base_op's path is shorter or equal to new_op, such as:
// new_op, base_op
// [p1,p2,p3], [p1,p2,p3]. same operand and base_op is prefix of new_op
// [p1,p2,p4], [p1,p2,p3]. same operand
// [p1,p2,p3,p4,..], [p1,p2,p3], base_op is prefix of new_op
// [p1,p2,p4,p5,..], [p1,p2,p3]
let same_operand = is_same_operand(base_op, &new_op);
let base_op_is_prefix = base_op.path.is_prefix_of(&new_op.path);
match &base_op.operator {
Operator::SubType(base_sub_type, base_op_operand, base_f) => {
if let Operator::SubType(new_op_subtype, new_op_operand, _) = &new_op.operator {
if base_sub_type.eq(new_op_subtype) {
return base_f
.transform(new_op_operand, base_op_operand, side)?
.into_iter()
.map(|new_operand| {
OperationComponent::new(
base_op.path.clone(),
Operator::SubType(
base_sub_type.clone(),
new_operand,
base_f.box_clone(),
),
)
})
.collect::<Result<Vec<OperationComponent>>>();
}
}
}
Operator::ListReplace(li_v, _) => {
if base_op_is_prefix {
if !same_operand {
return Ok(vec![]);
}
if let Operator::ListReplace(new_li, _) = &new_op.operator {
if side == TransformSide::LEFT {
return Ok(vec![OperationComponent::new(
new_op.path,
Operator::ListReplace(new_li.clone(), li_v.clone()),
)?]);
} else {
return Ok(vec![]);
}
}
if let Operator::ListDelete(_) = &new_op.operator {
return Ok(vec![]);
}
}
}
Operator::ListInsert(_) => {
if let Operator::ListInsert(_) = &new_op.operator {
if same_operand && base_op_is_prefix {
if side == TransformSide::RIGHT {
new_op.path.increase_index(base_operate_path_len);
}
return Ok(vec![new_op]);
}
}
if base_op
.path
.get(base_operate_path_len)
.and_then(|p1| new_op.path.get(base_operate_path_len).map(|p2| p1 <= p2))
.unwrap_or(false)
{
new_op.path.increase_index(base_operate_path_len);
}
if let Operator::ListMove(lm) = &mut new_op.operator {
if same_operand
&& base_op
.path
.get(base_operate_path_len)
.map(|p| p <= &PathElement::Index(*lm))
.unwrap_or(false)
{
new_op.operator = Operator::ListMove(*lm + 1);
}
}
}
Operator::ListDelete(_) => {
let base_op_operate_path = base_op.path.get(base_operate_path_len).unwrap();
let new_op_operate_path = new_op.path.get(base_operate_path_len).unwrap();
if let Operator::ListMove(lm) = new_op.operator {
if same_operand {
if base_op_is_prefix {
// base_op deleted the thing we're trying to move
return Ok(vec![]);
}
let to = lm.into();
if base_op_operate_path < &to
|| (base_op_operate_path.eq(&to) && new_op_operate_path < &to)
{
new_op.operator = Operator::ListMove(lm - 1);
}
}
}
if base_op_operate_path < new_op_operate_path {
new_op.path.decrease_index(base_operate_path_len);
} else if base_op_is_prefix {
if !same_operand {
// we're below the deleted element, so -> noop
return Ok(vec![]);
}
if let Operator::ListDelete(_) = new_op.operator {
// we're trying to delete the same element, -> noop
return Ok(vec![]);
}
if let Operator::ListReplace(li, _) = new_op.operator {
// we're replacing, they're deleting. we become an insert.
return Ok(vec![OperationComponent::new(
new_op.path.clone(),
Operator::ListInsert(li.clone()),
)?]);
}
}
}
Operator::ObjectReplace(oi, _) => {
if base_op_is_prefix {
if !same_operand {
return Ok(vec![]);
}
match &new_op.operator {
Operator::ObjectReplace(new_oi, _) | Operator::ObjectInsert(new_oi) => {
if side == TransformSide::RIGHT {
return Ok(vec![]);
}
return Ok(vec![OperationComponent {
path: new_op.path.clone(),
operator: Operator::ObjectReplace(new_oi.clone(), oi.clone()),
}]);
}
_ => {
return Ok(vec![]);
}
}
}
}
Operator::ObjectInsert(base_oi) => {
if base_op_is_prefix {
if let Operator::ObjectReplace(new_oi, _) | Operator::ObjectInsert(new_oi) =
&new_op.operator
{
if side == TransformSide::LEFT {
if same_operand {
return Ok(vec![OperationComponent {
path: base_op.path.clone(),
operator: Operator::ObjectReplace(
new_oi.clone(),
base_oi.clone(),
),
}]);
}
// Here, we are different from original json0
// eg: new_op = [{"p": ["p1", "p2"],"oi": "v1"}], base_op = [{"p": ["p1"],"oi": "v2"}]
// after execution of these op, the result should be {"p1":{"p2":"v1"}}, so new_op after left transform
// is [{"p": ["p1"],"od": "v2"}, {"p": ["p1", "p2"],"oi": "v1"}]
// but original json0 is [{"p": ["p1", "p2"],"od": "v2"}, {"p": ["p1", "p2"],"oi": "v1"}]
// the problem of original json0 is "v2" inserted by base_op is under path p1, not [p1, p2]
return Ok(vec![
OperationComponent {
path: base_op.path.clone(),
operator: Operator::ObjectDelete(base_oi.clone()),
},
new_op,
]);
} else {
return Ok(vec![]);
}
} else if let Operator::ObjectDelete(_) = &new_op.operator {
if side == TransformSide::RIGHT {
return Ok(vec![]);
}
}
}
}
Operator::ObjectDelete(_) => {
if base_op_is_prefix {
if !same_operand {
return Ok(vec![]);
}
if let Operator::ObjectReplace(new_oi, _) | Operator::ObjectInsert(new_oi) =
&new_op.operator
{
if side == TransformSide::LEFT {
return Ok(vec![OperationComponent {
path: new_op.path.clone(),
operator: Operator::ObjectInsert(new_oi.clone()),
}]);
} else {
return Ok(vec![]);
}
} else {
return Ok(vec![]);
}
}
}
Operator::ListMove(lm) => {
if same_operand {
match &mut new_op.operator {
Operator::ListMove(new_op_lm) => {
let other_from = base_op.path.get(new_operate_path_len).unwrap();
let other_to = PathElement::Index(*lm);
if other_from == &other_to {
return Ok(vec![new_op]);
}
let from = new_op.path.get(new_operate_path_len).unwrap().clone();
let to: PathElement = PathElement::Index(*new_op_lm);
if &from == other_from {
if to == other_to {
// already moved to where we want
return Ok(vec![]);
}
if side == TransformSide::LEFT {
new_op.path.replace(base_operate_path_len, other_to.clone());
if from == to {
new_op.operator = base_op.operator.clone();
}
} else {
return Ok(vec![]);
}
} else {
let mut n_lm = *new_op_lm;
if &from > other_from {
new_op.path.decrease_index(base_operate_path_len);
}
if from > other_to {
new_op.path.increase_index(base_operate_path_len);
} else if from == other_to && other_from > &other_to {
new_op.path.increase_index(base_operate_path_len);
if from == to {
n_lm += 1;
}
}
if &to > other_from || (&to == other_from && to > from) {
n_lm -= 1;
}
if to > other_to {
n_lm += 1;
} else if to == other_to {
if (&other_to > other_from && to > from)
|| (&other_to < other_from && to < from)
{
if side == TransformSide::RIGHT {
n_lm += 1;
}
} else if to > from {
n_lm += 1;
} else if &to == other_from {
n_lm -= 1;
}
}
new_op.operator = Operator::ListMove(n_lm);
}
return Ok(vec![new_op]);
}
Operator::ListInsert(_) => {
let operate_index = base_operate_path_len;
let from = base_op.path.get(operate_index).unwrap();
let to = *lm;
let p = new_op.path.get(operate_index).unwrap().clone();
if &p > from {
new_op.path.decrease_index(operate_index);
}
if p > PathElement::Index(to) {
new_op.path.increase_index(operate_index);
}
return Ok(vec![new_op]);
}
_ => {}
}
}
let from = base_op.path.get(base_operate_path_len).unwrap();
let to = PathElement::Index(*lm);
let p = new_op.path.get(base_operate_path_len).unwrap().clone();
if &p == from {
new_op.path.replace(base_operate_path_len, to.clone());
} else {
if &p > from {
new_op.path.decrease_index(base_operate_path_len);
}
if p > to || (p == to && from > &to) {
new_op.path.increase_index(base_operate_path_len);
}
}
}
_ => {}
}
Ok(vec![new_op])
}
pub fn consume(
&self,
op: &mut OperationComponent,
common_path: &Path,
other: &OperationComponent,
) -> Result<()> {
match &mut op.operator {
Operator::ListDelete(v)
| Operator::ListReplace(_, v)
| Operator::ObjectDelete(v)
| Operator::ObjectReplace(_, v) => {
let (_, p2) = other.path.split_at(common_path.len());
// v maybe cannot apply other.operator
// if that happen we do not consume other just leave origin op
_ = v.apply(p2, other.operator.clone());
}
_ => {}
}
Ok(())
}
}