Support hardcoded starting prices.

The Coindesk API doesn't have data going all the way back. But since history
isn't changing, we can simply put in known prices.

Also, extend the CDPR cells to have four digits instead of just two.

config/default.yaml

@@ -28,6 +28,12 @@ defaults:
     time: 2019-12-31T16:00:00-08:00
   - name: 2017-
     time: 2016-12-31T16:00:00-08:00
+  - name: 2013-
+    time: 2012-12-31T16:00:00-08:00
+    startingPrice: 13.30
+  - name: 2011-
+    time: 2010-12-31T16:00:00-08:00
+    startingPrice: 0.30
 
 assets:
   ETH:
@@ -44,6 +50,11 @@ assets:
       value: 20000
     - name: $25k
       value: 25000
+    constantBases:
+    - name: 2020-
+      time: 2019-12-31T16:00:00-08:00
+    - name: 2017-
+      time: 2016-12-31T16:00:00-08:00
   LTC:
     goals:
     - name: $100

moon/moon.go

@@ -2,6 +2,8 @@ package moon
 
 import (
 	"context"
+	"errors"
+	"fmt"
 	"math"
 	"time"
 
@@ -74,30 +76,10 @@ func (m *Math) Refresh(ctx context.Context) (err error) {
 	tasks.WithMaxGoroutines(len(m.Columns))
 	//tasks.WithMaxGoroutines(1)
 	now := time.Now()
-
 	for i := range m.Columns {
 		c := &m.Columns[i]
 		tasks.Go(func() error {
-			c.StartingDate = c.Base.From(now)
-			nextDay := c.StartingDate.Add(time.Hour * 24)
-			resp, err := coindesk.GetPriceValues(ctx,
-				m.Asset, c.StartingDate, nextDay)
-			if err != nil {
-				return err
-			}
-			if len(resp.Data.Entries) == 0 {
-				c.Projections.Dates = nil
-				return nil
-			}
-			c.StartingPrice = resp.Data.Entries[0].Price
-			c.Gain = float64(m.CurrentPrice) / float64(c.StartingPrice)
-			days := now.Sub(c.StartingDate).Hours() / 24
-			c.CDPR = CDPR(days, c.Gain)
-			c.Projections = ProjectDates(
-				now, float64(m.CurrentPrice),
-				c.CDPR, m.Goals,
-			)
-			return nil
+			return c.project(ctx, m, now)
 		})
 	}
 	err = tasks.Wait()
@@ -114,27 +96,49 @@ type Column struct {
 	Projections   Projection
 }
 
-var DefaultGoals = []Goal{
-	{"$100k", 100000},
-	{"$150k", 150000},
-	{"$200k", 200000},
-	{"$250k", 250000},
-	{"$300k", 300000},
-	{"$500k", 500000},
-	{"$1m", 1000000},
+func (c *Column) project(ctx context.Context, m *Math, now time.Time) (err error) {
+	err = c.fillStartingPrice(ctx, m.Asset, now)
+	if err != nil {
+		return
+	}
+
+	c.Gain = float64(m.CurrentPrice) / float64(c.StartingPrice)
+	days := now.Sub(c.StartingDate).Hours() / 24
+	c.CDPR = CDPR(days, c.Gain)
+	c.Projections = ProjectDates(
+		now, float64(m.CurrentPrice),
+		c.CDPR, m.Goals,
+	)
+	return
 }
 
-var DefaultConstantBases = []ConstantBase{
-	{"2020-", time.Unix(1577836800, 0)},
-	{"2017-", time.Unix(1483228800, 0)},
+func (c *Column) fillStartingPrice(
+	ctx context.Context, asset coindesk.Asset, now time.Time,
+) error {
+	// if base provides a hardcoded starting price, use it
+	c.StartingDate = c.Base.From(now)
+	c.StartingPrice = coindesk.Price(c.Base.GetStartingPrice())
+	if c.StartingPrice != 0 {
+		return nil
+	}
+
+	// otherwise, look up the starting price via Coindesk
+	nextDay := c.StartingDate.Add(time.Hour * 24)
+	resp, err := coindesk.GetPriceValues(ctx, asset, c.StartingDate, nextDay)
+	if err != nil {
+		err = fmt.Errorf("getting price for %s on %v: %w",
+			asset, c.StartingDate, err)
+		return err
+	}
+	if len(resp.Data.Entries) == 0 {
+		c.Projections.Dates = nil
+		return errEmptyPriceEntries
+	}
+	c.StartingPrice = resp.Data.Entries[0].Price
+	return nil
 }
 
-var DefaultRelativeBases = []RelativeBase{
-	{"Month", time.Duration(-30) * time.Hour * 24},
-	{"Quarter", time.Duration(-90) * time.Hour * 24},
-	{"Half-Year", time.Duration(-182) * time.Hour * 24},
-	{"Year", time.Duration(-365) * time.Hour * 24},
-}
+var errEmptyPriceEntries = errors.New("price values response has no entries")
 
 type Goal struct {
 	Name  string  `koanf:"name"`
@@ -145,12 +149,14 @@ type Goal struct {
 type Base interface {
 	From(now time.Time) time.Time
 	Label() string
+	GetStartingPrice() float64
 }
 
 // ConstantBase is a base that is a constant time, e.g. 2020-01-01.
 type ConstantBase struct {
-	Name string    `koanf:"name"`
-	Time time.Time `koanf:"time"`
+	Name          string    `koanf:"name"`
+	Time          time.Time `koanf:"time"`
+	StartingPrice float64   `koanf:"startingPrice"`
 }
 
 func (cb ConstantBase) From(_ time.Time) time.Time {
@@ -161,6 +167,10 @@ func (cb ConstantBase) Label() string {
 	return cb.Name
 }
 
+func (cb ConstantBase) GetStartingPrice() float64 {
+	return cb.StartingPrice
+}
+
 // RelativeBase is a base that is relative, e.g. "90 days ago."
 type RelativeBase struct {
 	Name   string        `koanf:"name"`
@@ -175,3 +185,7 @@ func (rb RelativeBase) From(now time.Time) time.Time {
 func (rb RelativeBase) Label() string {
 	return rb.Name
 }
+
+func (rb RelativeBase) GetStartingPrice() float64 {
+	return 0
+}

moon/moon_test.go

@@ -11,6 +11,14 @@ func TestCDPR(t *testing.T) {
 }
 
 func TestProjection(t *testing.T) {
-	p := moon.ProjectDates(time.Now(), 68900, 1.0055, moon.DefaultGoals)
+	p := moon.ProjectDates(time.Now(), 68900, 1.0055, []moon.Goal{
+		{"$100k", 100000},
+		{"$150k", 150000},
+		{"$200k", 200000},
+		{"$250k", 250000},
+		{"$300k", 300000},
+		{"$500k", 500000},
+		{"$1m", 1000000},
+	})
 	_ = p
 }

tui/asset/asset.go

@@ -206,7 +206,7 @@ func refillProjections(m *Model) {
 
 func renderEntries(c moon.Column) (entries []string) {
 	entries = append(entries, fmt.Sprintf("$%.2f", c.StartingPrice))
-	entries = append(entries, fmt.Sprintf("%.2f%%", (c.CDPR-1)*100))
+	entries = append(entries, fmt.Sprintf("%.4f%%", (c.CDPR-1)*100))
 	never := c.CDPR <= 1
 	for i := range c.Projections.Dates {
 		var cell string