feat: Use currencyConvert function when calculating revenue

Let's now actually use the `currencyConvert` function when computing Revenue on the Web Analytics panel. We make a lot of effort to only actually try converting it if there's something to convert.

Author: rafaeelaudibert

posthog/hogql/database/schema/exchange_rate.py

@@ -1,3 +1,7 @@
+from typing import Union
+
+from posthog.hogql import ast
+from posthog.schema import CurrencyCode, RevenueTrackingConfig, RevenueTrackingEventItem
 from posthog.hogql.database.models import (
     StringDatabaseField,
     DateDatabaseField,
@@ -19,3 +23,120 @@ def to_printed_clickhouse(self, context):
 
     def to_printed_hogql(self):
         return "exchange_rate"
+
+
+def convert_currency_call(
+    amount: ast.Expr, currency_from: ast.Expr, currency_to: ast.Expr, timestamp: ast.Expr | None = None
+) -> ast.Expr:
+    args = [currency_from, currency_to, amount]
+    if timestamp:
+        args.append(timestamp)
+
+    return ast.Call(name="convertCurrency", args=args)
+
+
+def revenue_comparison_and_value_exprs(
+    event: RevenueTrackingEventItem, config: RevenueTrackingConfig
+) -> tuple[ast.Expr, ast.Expr]:
+    # Check whether the event is the one we're looking for
+    comparison_expr = ast.CompareOperation(
+        left=ast.Field(chain=["event"]),
+        op=ast.CompareOperationOp.Eq,
+        right=ast.Constant(value=event.eventName),
+    )
+
+    # If there's a revenueCurrencyProperty, convert the revenue to the base currency from that property
+    # Otherwise, assume we're already in the base currency
+    # Also, assume that `base_currency` is USD by default, it'll be empty for most customers
+    if event.revenueCurrencyProperty:
+        value_expr = ast.Call(
+            name="if",
+            args=[
+                ast.Call(
+                    name="isNull", args=[ast.Field(chain=["events", "properties", event.revenueCurrencyProperty])]
+                ),
+                ast.Call(
+                    name="toDecimal",
+                    args=[
+                        ast.Field(chain=["events", "properties", event.revenueProperty]),
+                        ast.Constant(value=10),
+                    ],
+                ),
+                convert_currency_call(
+                    ast.Field(chain=["events", "properties", event.revenueProperty]),
+                    ast.Field(chain=["events", "properties", event.revenueCurrencyProperty]),
+                    ast.Constant(value=(config.baseCurrency or CurrencyCode.USD).value),
+                    ast.Call(name="DATE", args=[ast.Field(chain=["events", "timestamp"])]),
+                ),
+            ],
+        )
+    else:
+        value_expr = ast.Call(
+            name="toDecimal",
+            args=[ast.Field(chain=["events", "properties", event.revenueProperty]), ast.Constant(value=10)],
+        )
+
+    return (comparison_expr, value_expr)
+
+
+def revenue_expression(config: Union[RevenueTrackingConfig, dict, None]) -> ast.Expr:
+    if isinstance(config, dict):
+        config = RevenueTrackingConfig.model_validate(config)
+
+    if not config or not config.events:
+        return ast.Constant(value=None)
+
+    exprs: list[ast.Expr] = []
+    for event in config.events:
+        comparison_expr, value_expr = revenue_comparison_and_value_exprs(event, config)
+        exprs.extend([comparison_expr, value_expr])
+
+    # Else clause, make sure there's a None at the end
+    exprs.append(ast.Constant(value=None))
+
+    return ast.Call(name="multiIf", args=exprs)
+
+
+def revenue_sum_expression(config: Union[RevenueTrackingConfig, dict, None]) -> ast.Expr:
+    if isinstance(config, dict):
+        config = RevenueTrackingConfig.model_validate(config)
+
+    if not config or not config.events:
+        return ast.Constant(value=None)
+
+    exprs: list[ast.Expr] = []
+    for event in config.events:
+        comparison_expr, value_expr = revenue_comparison_and_value_exprs(event, config)
+
+        exprs.append(
+            ast.Call(
+                name="sumIf",
+                args=[
+                    ast.Call(name="ifNull", args=[value_expr, ast.Constant(value=0)]),
+                    comparison_expr,
+                ],
+            )
+        )
+
+    if len(exprs) == 1:
+        return exprs[0]
+
+    return ast.Call(name="plus", args=exprs)
+
+
+def revenue_events_where_expr(config: Union[RevenueTrackingConfig, dict, None]) -> ast.Expr:
+    if isinstance(config, dict):
+        config = RevenueTrackingConfig.model_validate(config)
+
+    if not config or not config.events:
+        return ast.Constant(value=False)
+
+    exprs: list[ast.Expr] = []
+    for event in config.events:
+        comparison_expr, _value_expr = revenue_comparison_and_value_exprs(event, config)
+        exprs.append(comparison_expr)
+
+    if len(exprs) == 1:
+        return exprs[0]
+
+    return ast.Or(exprs=exprs)

posthog/hogql_queries/utils/revenue.py

@@ -5,7 +5,7 @@
 from posthog.hogql.constants import LimitContext
 from posthog.hogql_queries.insights.paginators import HogQLHasMorePaginator
 from posthog.hogql_queries.query_runner import QueryRunner
-from posthog.hogql_queries.utils.revenue import revenue_expression, revenue_events_expr
+from posthog.hogql.database.schema.exchange_rate import revenue_expression, revenue_events_where_expr
 from posthog.schema import (
     RevenueExampleEventsQuery,
     RevenueExampleEventsQueryResponse,
@@ -56,7 +56,7 @@ def to_query(self) -> ast.SelectQuery:
             select_from=ast.JoinExpr(table=ast.Field(chain=["events"])),
             where=ast.And(
                 exprs=[
-                    revenue_events_expr(tracking_config),
+                    revenue_events_where_expr(tracking_config),
                     ast.CompareOperation(
                         op=CompareOperationOp.NotEq,
                         left=ast.Field(chain=["revenue"]),  # refers to the Alias above