From e771a40901b82d65392d14438e952bf1ac056177 Mon Sep 17 00:00:00 2001
From: bel <bel@bel.bel>
Date: Sun, 15 Oct 2023 11:39:31 -0600
Subject: [PATCH] implement analyzer.go:Analyzer:LargestTransaction to return
 the first largest transaction in slice

---
 digits-work-sample-go.d/analyzer.go | 18 ++++++++-----
 digits-work-sample-go.d/errors.go   |  7 ++++++
 todo.yaml                           | 39 ++++++++++++++++++++++++++++-
 3 files changed, 57 insertions(+), 7 deletions(-)
 create mode 100644 digits-work-sample-go.d/errors.go

diff --git a/digits-work-sample-go.d/analyzer.go b/digits-work-sample-go.d/analyzer.go
index 48d3363..ad14b95 100644
--- a/digits-work-sample-go.d/analyzer.go
+++ b/digits-work-sample-go.d/analyzer.go
@@ -1,7 +1,5 @@
 package analyzer
 
-import "errors"
-
 // Analyzer processes Transactions and generates reports.
 type Analyzer struct {
 	// The list of Transactions available to analyze.
@@ -28,11 +26,19 @@ func (anz *Analyzer) TransactionsAmount() Amount {
 // the absolute value of the transaction amount. Returns an error if there
 // are no transactions.
 //
-// - Note: Large negative transactions are still large--it just means the
-//         money moved the other direction.
+//   - Note: Large negative transactions are still large--it just means the
+//     money moved the other direction.
 func (anz *Analyzer) LargestTransaction() (Transaction, error) {
-	// TODO: Not implemented.
-	return Transaction{}, errors.New("not implemented")
+	if anz == nil || len(anz.transactions) == 0 {
+		return Transaction{}, ErrNoTransactionsToAnalyze
+	}
+	largestIdx := 0
+	for i := 1; i < len(anz.transactions); i++ {
+		if anz.transactions[largestIdx].Amount.AbsoluteValue() < anz.transactions[i].Amount.AbsoluteValue() {
+			largestIdx = i
+		}
+	}
+	return anz.transactions[largestIdx], nil
 }
 
 // ByCategory groups the transactions by category and returns a map of
diff --git a/digits-work-sample-go.d/errors.go b/digits-work-sample-go.d/errors.go
new file mode 100644
index 0000000..06d6ecf
--- /dev/null
+++ b/digits-work-sample-go.d/errors.go
@@ -0,0 +1,7 @@
+package analyzer
+
+import "errors"
+
+var (
+	ErrNoTransactionsToAnalyze = errors.New("no transactions to analyze")
+)
diff --git a/todo.yaml b/todo.yaml
index bee9fef..7d51758 100755
--- a/todo.yaml
+++ b/todo.yaml
@@ -2,7 +2,6 @@ todo:
 - review readme tail to finish // answer 3 questions, gofmt
 - todo: go test
   subtasks:
-  - TestAnalyzer_LargestTransaction
   - TestAnalyzer_DuplicatesExcluded
   - TestAnalyzer_GroupByCategory
   - TestAnalyzer_BigSpendersReport
@@ -16,6 +15,8 @@ todo:
     not be changed, or even what currency Amount is
   - transaction.go:Transaction:Sum again doesnt care about Amount currency or vendor/vendee
     drift
+  - analyzer.go:Analyzer:LargestTransaction doesn't specify how to break ties; stable
+    or latest?
 scheduled: []
 done:
 - todo: hello world
@@ -451,3 +452,39 @@ done:
   - transaction.go:Transaction:Sum again doesnt care about Amount currency or vendor/vendee
     drift
   ts: Sun Oct 15 11:36:45 MDT 2023
+- todo: go test
+  subtasks:
+  - TestAnalyzer_LargestTransaction
+  - TestAnalyzer_DuplicatesExcluded
+  - TestAnalyzer_GroupByCategory
+  - TestAnalyzer_BigSpendersReport
+  - TestAnalyzer_TransactionsFromURLs
+  - TestAnalyzer_TransactionsFromURLsConcurrent
+  - amount.go:Rounded probably does NOT handle float precision well... it is float64
+    tho...
+  - my `go mod tidy` actually cleared `go.mod` file, probably weird localhost backwards
+    compatilble stuff
+  - transaction.go:Transaction:String not clear if FormatUSD or amount currency should
+    not be changed, or even what currency Amount is
+  - transaction.go:Transaction:Sum again doesnt care about Amount currency or vendor/vendee
+    drift
+  ts: Sun Oct 15 11:38:22 MDT 2023
+- todo: go test
+  subtasks:
+  - TestAnalyzer_LargestTransaction
+  - TestAnalyzer_DuplicatesExcluded
+  - TestAnalyzer_GroupByCategory
+  - TestAnalyzer_BigSpendersReport
+  - TestAnalyzer_TransactionsFromURLs
+  - TestAnalyzer_TransactionsFromURLsConcurrent
+  - amount.go:Rounded probably does NOT handle float precision well... it is float64
+    tho...
+  - my `go mod tidy` actually cleared `go.mod` file, probably weird localhost backwards
+    compatilble stuff
+  - transaction.go:Transaction:String not clear if FormatUSD or amount currency should
+    not be changed, or even what currency Amount is
+  - transaction.go:Transaction:Sum again doesnt care about Amount currency or vendor/vendee
+    drift
+  - analyzer.go:Analyzer:LargestTransaction doesn't specify how to break ties; stable
+    or latest?
+  ts: Sun Oct 15 11:38:46 MDT 2023