task-059: req-eng's tank balance UI

10 files changed, 70 insertions, 11 deletions

diff --git a/requirements/catalogue/req-000.md b/requirements/catalogue/req-000.md
index bc98fcc..1d7b69b 100644
--- a/requirements/catalogue/req-000.md
+++ b/requirements/catalogue/req-000.md
@@ -5,6 +5,6 @@ that I don't go bankrupt.
 
 Source: need-000
 
-Satisfied by: req-068, req-069, req-085, ass-020
+Satisfied by: req-068, req-069, req-085, req-001, req-091, ass-020
 
 Relates to: req-086, req-087
diff --git a/requirements/catalogue/req-025.md b/requirements/catalogue/req-025.md
index 16faad9..c2be0cb 100644
--- a/requirements/catalogue/req-025.md
+++ b/requirements/catalogue/req-025.md
@@ -5,6 +5,6 @@ that I can use my money well.
 
 Source: need-001
 
-Satisfied by: req-068, req-069, req-085, ass-020
+Satisfied by: req-068, req-069, req-085, req-001, req-091, ass-020
 
 Relates to: req-086, req-087
diff --git a/requirements/catalogue/req-085.md b/requirements/catalogue/req-085.md
index c8ce9af..c40e2c7 100644
--- a/requirements/catalogue/req-085.md
+++ b/requirements/catalogue/req-085.md
@@ -1,9 +1,10 @@
 # req-085
 
 As a user, when I'm creating, updating and deleting my buckets and pipes, I want
-to see a prominent number which summarises the long-term difference between my
-planned incomings and outgoings, so that my incomings and outgoings are roughly
-equal in the long run.
+to see a prominent number which summarises what the long-term difference between
+what my incomings and outgoings will be in the future if I control what I do
+with my money, so that my incomings and outgoings are roughly equal in the
+long run.
 
 Sources: req-025, req-000
 
diff --git a/requirements/catalogue/req-088.md b/requirements/catalogue/req-088.md
index a1791fa..7998b45 100644
--- a/requirements/catalogue/req-088.md
+++ b/requirements/catalogue/req-088.md
@@ -3,8 +3,9 @@
 As a user, when I'm creating, updating and deleting my buckets and pipes, I want
 to see the result of the procedure,
 `calculate_long_term_expected_monthly_tank_change`, described below,
-prominently, so that I see a prominent number which summarises the long-term
-difference between my planned incomings and outgoings.
+prominently, so that I see a prominent number which I know summarises what
+the long-term difference between what my incomings and outgoings will be in
+the future if I control what I do with my money.
 
 Source: req-085
 
diff --git a/requirements/catalogue/req-089.md b/requirements/catalogue/req-089.md
index 349d4d9..fb86ace 100644
--- a/requirements/catalogue/req-089.md
+++ b/requirements/catalogue/req-089.md
@@ -3,8 +3,9 @@
 As a user, when I'm creating, updating and deleting my buckets and pipes in
 Schist's desktop UI, I want to see the result of the procedure,
 `calculate_long_term_expected_monthly_tank_change`, as described in req-088,
-prominently, so that I see a prominent number which summarises the long-term
-difference between my planned incomings and outgoings.
+prominently, so that I see a prominent number which I know summarises the long-term
+difference between what my incomings and outgoings will be in the future if I
+control what I do with my money.
 
 Source: req-088
 
diff --git a/requirements/catalogue/req-090.md b/requirements/catalogue/req-090.md
index 5b72fca..8a574cd 100644
--- a/requirements/catalogue/req-090.md
+++ b/requirements/catalogue/req-090.md
@@ -3,8 +3,9 @@
 As a user, when I'm creating, updating and deleting my buckets and pipes in
 Schist's Web UI, I want to see the result of the procedure,
 `calculate_long_term_expected_monthly_tank_change`, as described in req-088,
-prominently, so that I see a prominent number which summarises the long-term
-difference between my planned incomings and outgoings.
+prominently, so that I see a prominent number which I know summarises the long-term
+difference between what my incomings and outgoings will be in the future if I
+control what I do with my money.
 
 Source: req-088
 
diff --git a/requirements/catalogue/req-091.md b/requirements/catalogue/req-091.md
new file mode 100644
index 0000000..f718eb8
--- /dev/null
+++ b/requirements/catalogue/req-091.md
@@ -0,0 +1,12 @@
+# req-091
+
+As a user, when I'm creating, updating and deleting my buckets and pipes, I want
+to see a prominent number which I know summarises what the difference between
+my incomings and outgoings has actually been in the past, so that my incomings
+and outgoings are roughly equal in the long run.
+
+Sources: req-025, req-000
+
+Satisfied by: req-092
+
+Relates to: req-085
diff --git a/requirements/catalogue/req-092.md b/requirements/catalogue/req-092.md
new file mode 100644
index 0000000..cde945e
--- /dev/null
+++ b/requirements/catalogue/req-092.md
@@ -0,0 +1,21 @@
+# req-092
+
+As a user, when I'm creating, updating and deleting my buckets and pipes, I want
+to see the result of the procedure,
+`calculate_tank_balance`, described below,
+so that I see a prominent number which I know summarises what the difference
+between my incomings and outgoings has actually been in the past, so that my
+incomings and outgoings are roughly equal in the long run.
+
+Source: req-091
+
+Satisfied by: dml-drip, dml-transaction, dml-bucket, ass-009, ass-021, req-093, req-094
+
+## calculate_tank_balance
+
+1. Let `drip_sum` be the sum of all `drip.amount` for all drips `drip`.
+2. Let `transaction_sum` be the sum of all `transaction.amount` for all
+   transactions `transaction`.
+3. Let `bucket_overdraw_sum` be the sum of all `bucket.balance` for all buckets
+   `bucket` such that `bucket.balance < 0`.
+4. Return `transaction_sum + bucket_overdraw_sum - drip_sum`.
diff --git a/requirements/catalogue/req-093.md b/requirements/catalogue/req-093.md
new file mode 100644
index 0000000..b150fb7
--- /dev/null
+++ b/requirements/catalogue/req-093.md
@@ -0,0 +1,11 @@
+# req-093
+
+As a user, when I'm creating, updating and deleting my buckets and pipes in
+Schist's desktop UI, I want to see the result of the procedure,
+`calculate_tank_balance`, as described in req-092, prominently, so that I see a
+prominent number which I know summarises what the difference between my
+incomings and outgoings has actually been in the past.
+
+Source: req-092
+
+Satisfied by: req-068, req-069, task-0
diff --git a/requirements/catalogue/req-094.md b/requirements/catalogue/req-094.md
new file mode 100644
index 0000000..ef6ee43
--- /dev/null
+++ b/requirements/catalogue/req-094.md
@@ -0,0 +1,11 @@
+# req-094
+
+As a user, when I'm creating, updating and deleting my buckets and pipes in
+Schist's Web UI, I want to see the result of the procedure,
+`calculate_tank_balance`, as described in req-092, prominently, so that I see a
+prominent number which I know summarises what the difference between my
+incomings and outgoings has actually been in the past.
+
+Source: req-092
+
+Satisfied by: req-068, req-069, task-058