Scan NWS forecast discussion blocks once

2026-08-02 22:56:03 +00:00
parent 2b19a121fa
commit 0a3e52d0e5
2 changed files with 176 additions and 76 deletions
--- a/internal/providers/nws/forecast_discussion.go
+++ b/internal/providers/nws/forecast_discussion.go
@@ -121,22 +121,30 @@ func ParseForecastDiscussionText(text string) (ForecastDiscussion, error) {
 		IssuedAt:   issuedAt.UTC(),
 	}

-	if block, ok := extractForecastDiscussionSection(lines, forecastDiscussionSectionForRole(forecastDiscussionSectionRoleKeyMessages)); ok {
-		out.KeyMessages = parseForecastDiscussionKeyMessages(block.body)
-	}
-	if block, ok := extractForecastDiscussionSection(lines, forecastDiscussionSectionForRole(forecastDiscussionSectionRoleShortTerm)); ok {
-		section, err := parseForecastDiscussionTextSection(block)
-		if err != nil {
-			return ForecastDiscussion{}, fmt.Errorf("parse %s: %w", block.heading.section, err)
+	seenRoles := make(map[forecastDiscussionSectionRole]bool, len(forecastDiscussionSectionRoles))
+	for _, block := range parseForecastDiscussionSectionBlocks(lines) {
+		role, ok := forecastDiscussionSectionRoles[block.heading.section]
+		if !ok || seenRoles[role] {
+			continue
 		}
-		out.ShortTerm = &section
-	}
-	if block, ok := extractForecastDiscussionSection(lines, forecastDiscussionSectionForRole(forecastDiscussionSectionRoleLongTerm)); ok {
-		section, err := parseForecastDiscussionTextSection(block)
-		if err != nil {
-			return ForecastDiscussion{}, fmt.Errorf("parse %s: %w", block.heading.section, err)
+		seenRoles[role] = true
+
+		switch role {
+		case forecastDiscussionSectionRoleKeyMessages:
+			out.KeyMessages = parseForecastDiscussionKeyMessages(block.body)
+		case forecastDiscussionSectionRoleShortTerm:
+			section, err := parseForecastDiscussionTextSection(block)
+			if err != nil {
+				return ForecastDiscussion{}, fmt.Errorf("parse %s: %w", block.heading.section, err)
+			}
+			out.ShortTerm = &section
+		case forecastDiscussionSectionRoleLongTerm:
+			section, err := parseForecastDiscussionTextSection(block)
+			if err != nil {
+				return ForecastDiscussion{}, fmt.Errorf("parse %s: %w", block.heading.section, err)
+			}
+			out.LongTerm = &section
 		}
-		out.LongTerm = &section
 	}

 	return out, nil
@@ -500,36 +508,42 @@ func isForecastDiscussionHorizontalWhitespace(b byte) bool {
 	return b == ' ' || b == '\t'
 }

-func forecastDiscussionSectionForRole(role forecastDiscussionSectionRole) string {
-	for section, registeredRole := range forecastDiscussionSectionRoles {
-		if registeredRole == role {
-			return section
-		}
-	}
-	return ""
-}
+func parseForecastDiscussionSectionBlocks(lines []string) []forecastDiscussionSectionBlock {
+	var blocks []forecastDiscussionSectionBlock
+	var active *forecastDiscussionSectionBlock

-func extractForecastDiscussionSection(lines []string, section string) (forecastDiscussionSectionBlock, bool) {
-	for i, raw := range lines {
-		heading, ok := parseForecastDiscussionSectionHeading(raw)
-		if !ok || heading.section != section {
+	finish := func() {
+		if active == nil {
+			return
+		}
+		blocks = append(blocks, *active)
+		active = nil
+	}
+
+	for _, raw := range lines {
+		line := strings.TrimSpace(raw)
+		if line == "$$" {
+			finish()
+			break
+		}
+		if line == "&&" || strings.Contains(line, "WATCHES/WARNINGS/ADVISORIES") {
+			finish()
 			continue
 		}

-		block := forecastDiscussionSectionBlock{heading: heading}
-		for j := i + 1; j < len(lines); j++ {
-			next := strings.TrimSpace(lines[j])
-			if next == "&&" || next == "$$" || strings.Contains(next, "WATCHES/WARNINGS/ADVISORIES") {
-				break
-			}
-			if _, ok := parseForecastDiscussionSectionHeading(next); ok {
-				break
-			}
-			block.body = append(block.body, lines[j])
+		heading, ok := parseForecastDiscussionSectionHeading(raw)
+		if ok {
+			finish()
+			active = &forecastDiscussionSectionBlock{heading: heading}
+			continue
+		}
+		if active != nil {
+			active.body = append(active.body, raw)
 		}
-		return block, true
 	}
-	return forecastDiscussionSectionBlock{}, false
+	finish()
+
+	return blocks
 }

 func parseForecastDiscussionKeyMessages(body []string) []string {
--- a/internal/providers/nws/forecast_discussion_test.go
+++ b/internal/providers/nws/forecast_discussion_test.go
@@ -236,41 +236,82 @@ func TestForecastDiscussionSectionRoleHeadingsParse(t *testing.T) {
 	}
 }

-func TestExtractForecastDiscussionSectionStopsAtSlashQualifiedHeading(t *testing.T) {
-	block, ok := extractForecastDiscussionSection([]string{
-		".LONG TERM /Monday through Next Saturday/...",
-		"Long-term prose.",
-		".AVIATION /18Z TAFS/...",
-		"Aviation prose.",
-	}, forecastDiscussionSectionForRole(forecastDiscussionSectionRoleLongTerm))
-	if !ok {
-		t.Fatalf("extractForecastDiscussionSection() found no LONG TERM block")
-	}
-	if block.heading.qualifier != "Monday through Next Saturday" {
-		t.Fatalf("qualifier = %q, want normalized slash qualifier", block.heading.qualifier)
-	}
-	wantBody := []string{"Long-term prose."}
-	if !reflect.DeepEqual(block.body, wantBody) {
-		t.Fatalf("body = %#v, want %#v", block.body, wantBody)
-	}
-}
-
-func TestExtractForecastDiscussionSectionAllowsEmptyBodyBeforeHeading(t *testing.T) {
-	block, ok := extractForecastDiscussionSection([]string{
+func TestParseForecastDiscussionSectionBlocksRetainsOrderAndEmptyBodies(t *testing.T) {
+	got := parseForecastDiscussionSectionBlocks([]string{
 		".SHORT TERM... (Tonight)",
 		".LONG TERM... (Tomorrow)",
 		"Long-term prose.",
-	}, forecastDiscussionSectionForRole(forecastDiscussionSectionRoleShortTerm))
-	if !ok {
-		t.Fatalf("extractForecastDiscussionSection() found no SHORT TERM block")
+	})
+	want := []forecastDiscussionSectionBlock{
+		{heading: forecastDiscussionSectionHeading{section: "SHORT TERM", qualifier: "(Tonight)"}},
+		{
+			heading: forecastDiscussionSectionHeading{section: "LONG TERM", qualifier: "(Tomorrow)"},
+			body:    []string{"Long-term prose."},
+		},
 	}
-	if len(block.body) != 0 {
-		t.Fatalf("body = %#v, want empty body", block.body)
+	if !reflect.DeepEqual(got, want) {
+		t.Fatalf("blocks = %#v, want %#v", got, want)
 	}
 }

-func TestExtractForecastDiscussionSectionKeepsMalformedHeadingLikeLines(t *testing.T) {
-	block, ok := extractForecastDiscussionSection([]string{
+func TestParseForecastDiscussionSectionBlocksStopsAtTerminators(t *testing.T) {
+	got := parseForecastDiscussionSectionBlocks([]string{
+		"Preamble is ignored.",
+		".KEY MESSAGES...",
+		"- First message.",
+		"&&",
+		".SHORT TERM...",
+		"Short-term prose.",
+		".LSX WATCHES/WARNINGS/ADVISORIES...",
+		"Watch text is ignored.",
+		"$$",
+		"WFO LSX",
+	})
+	want := []forecastDiscussionSectionBlock{
+		{
+			heading: forecastDiscussionSectionHeading{section: "KEY MESSAGES"},
+			body:    []string{"- First message."},
+		},
+		{
+			heading: forecastDiscussionSectionHeading{section: "SHORT TERM"},
+			body:    []string{"Short-term prose."},
+		},
+	}
+	if !reflect.DeepEqual(got, want) {
+		t.Fatalf("blocks = %#v, want %#v", got, want)
+	}
+}
+
+func TestParseForecastDiscussionSectionBlocksUsesGenericHeadingsAsBoundaries(t *testing.T) {
+	got := parseForecastDiscussionSectionBlocks([]string{
+		".SHORT TERM...",
+		"Short-term prose.",
+		".SYNOPSIS...",
+		"Synopsis prose.",
+		".LONG TERM /Tomorrow/...",
+		"Long-term prose.",
+	})
+	want := []forecastDiscussionSectionBlock{
+		{
+			heading: forecastDiscussionSectionHeading{section: "SHORT TERM"},
+			body:    []string{"Short-term prose."},
+		},
+		{
+			heading: forecastDiscussionSectionHeading{section: "SYNOPSIS"},
+			body:    []string{"Synopsis prose."},
+		},
+		{
+			heading: forecastDiscussionSectionHeading{section: "LONG TERM", qualifier: "Tomorrow"},
+			body:    []string{"Long-term prose."},
+		},
+	}
+	if !reflect.DeepEqual(got, want) {
+		t.Fatalf("blocks = %#v, want %#v", got, want)
+	}
+}
+
+func TestParseForecastDiscussionSectionBlocksKeepsMalformedHeadingLikeLines(t *testing.T) {
+	got := parseForecastDiscussionSectionBlocks([]string{
 		".SHORT TERM... (Tonight)",
 		".short term... Lowercase prose stays in the body.",
 		".LONG TERM /Tomorrow/..",
@@ -278,18 +319,63 @@ func TestExtractForecastDiscussionSectionKeepsMalformedHeadingLikeLines(t *testi
 		"Expected short-term prose.",
 		".LONG TERM... (Tomorrow)",
 		"Long-term prose.",
-	}, forecastDiscussionSectionForRole(forecastDiscussionSectionRoleShortTerm))
-	if !ok {
-		t.Fatalf("extractForecastDiscussionSection() found no SHORT TERM block")
+	})
+	want := []forecastDiscussionSectionBlock{
+		{
+			heading: forecastDiscussionSectionHeading{section: "SHORT TERM", qualifier: "(Tonight)"},
+			body: []string{
+				".short term... Lowercase prose stays in the body.",
+				".LONG TERM /Tomorrow/..",
+				".LONG TERM /Tomorrow/... more",
+				"Expected short-term prose.",
+			},
+		},
+		{
+			heading: forecastDiscussionSectionHeading{section: "LONG TERM", qualifier: "(Tomorrow)"},
+			body:    []string{"Long-term prose."},
+		},
 	}
-	wantBody := []string{
-		".short term... Lowercase prose stays in the body.",
-		".LONG TERM /Tomorrow/..",
-		".LONG TERM /Tomorrow/... more",
-		"Expected short-term prose.",
+	if !reflect.DeepEqual(got, want) {
+		t.Fatalf("blocks = %#v, want %#v", got, want)
 	}
-	if !reflect.DeepEqual(block.body, wantBody) {
-		t.Fatalf("body = %#v, want %#v", block.body, wantBody)
+}
+
+func TestParseForecastDiscussionTextKeepsFirstMappedSections(t *testing.T) {
+	text := strings.Join([]string{
+		"AFDLSX",
+		"National Weather Service Saint Louis MO",
+		"224 PM CDT Sat Mar 28 2026",
+		"",
+		".KEY MESSAGES...",
+		"&&",
+		".KEY MESSAGES...",
+		"- Second key message.",
+		"&&",
+		".SHORT TERM... (First short term)",
+		"First short-term prose.",
+		"&&",
+		".SHORT TERM... (Second short term)",
+		"Second short-term prose.",
+		"&&",
+		".LONG TERM... (First long term)",
+		"First long-term prose.",
+		"&&",
+		".LONG TERM... (Second long term)",
+		"Second long-term prose.",
+	}, "\n")
+
+	got, err := ParseForecastDiscussionText(text)
+	if err != nil {
+		t.Fatalf("ParseForecastDiscussionText() error = %v", err)
+	}
+	if len(got.KeyMessages) != 0 {
+		t.Fatalf("KeyMessages = %#v, want empty first block", got.KeyMessages)
+	}
+	if got.ShortTerm == nil || got.ShortTerm.Qualifier != "(First short term)" || got.ShortTerm.Text != "First short-term prose." {
+		t.Fatalf("ShortTerm = %#v, want first section", got.ShortTerm)
+	}
+	if got.LongTerm == nil || got.LongTerm.Qualifier != "(First long term)" || got.LongTerm.Text != "First long-term prose." {
+		t.Fatalf("LongTerm = %#v, want first section", got.LongTerm)
 	}
 }