Add changelog generation script and tools

Makefile

@@ -11,7 +11,7 @@ DIRWORK := $(shell pwd -P)
 
 .PHONY: all clean install lint format pull assets rules html pdf epub force
 .PHONY: check check-rules check-rules-duplicates check-rules-incorrects
-.PHONY: next-rule-id watch
+.PHONY: next-rule-id watch changelog
 
 all: clean html rules
 clean:
@@ -51,6 +51,9 @@ next-rule-id:
 	"RULE_IDS=($$(grep -rh "^.*\[#[0-9]\{1,5\}.*$$" $(DIRCONTENTS) | sort -r))"; \
 	echo $$(($$(echo $${RULE_IDS[0]} | tr -d '\[' | tr -d '\]' | tr -d '#') + 1));
 
+changelog:
+	$(DIRSCRIPTS)/changelog.sh --update
+
 assets:
 	mkdir -p $(DIRBUILDS);
 	cp -r assets $(DIRBUILDS)/;

scripts/changelog.prompt

@@ -0,0 +1,42 @@
+Write a changelog highlighting ONLY the rule changes based on the git commit messages and diffs provided.
+Formatting, infrastructure, or similar non-rule changes should be omitted.
+
+The rule numbers should always be referenced using angle brackets. For example, rule 211 should be written as <<211>>.
+
+At the end of every changelog row, you should add a link to the related Pull Request in AsciiDoc format, like so: ^https://github.com/zalando/restful-api-guidelines/pull/<PR_NUMBER>[#PR_NUMBER]^
+
+If there is no relevant Pull Request, you should link to a commit in asciidoc format instead, like so: ^https://github.com/zalando/restful-api-guidelines/commit/<COMMIT_HASH>[SHORT_HASH]^
+
+Example changelog:
+
+* `2021-12-09`: event id must not change in retry situations when producers <<211>>.
+* `2021-11-24`: restructuring of the document and some rules.
+* `2021-10-18`: new rule <<244>>.
+* `2021-10-12`: improve clarity on {PATCH} usage in rule <<148>>.
+* `2021-08-24`: improve clarity on {PUT} usage in rule <<148>>.
+* `2021-08-24`: only use codes registered via IANA in rule <<243>>.
+* `2021-08-17`: update formats per OpenAPI 3.1 in <<238>>.
+* `2021-06-22`: <<238>> changed from {SHOULD} to {MUST}; consistency for rules around standards for data.
+* `2021-06-03`: <<104>> with clear distinction of OpenAPI security schemes, favoring `bearer` to `oauth2`.
+* `2021-06-01`: resolve uncertainties around 'occurred_at' semantics of <<event-metadata, event metadata>>.
+* `2021-05-25`: <<172>> with <<114, API endpoint versioning>> as only custom media type usage exception.
+* `2021-05-05`: define usage on resource-ids in {PUT} and {POST} in <<148>>.
+* `2021-04-29`: improve clarity of <<133>>.
+* `2021-03-19`: clarity on <<167>>.
+* `2021-03-15`: <<242>> changed from {SHOULD} to {MUST}; improve clarity around <<203, event ordering>>.
+* `2021-03-19`: best practice section <<cursor-based-pagination>>
+* `2021-02-16`: define how to reference models outside the api in <<234>>.
+* `2021-02-15`: improve guideline <<176>> -- clients must be prepared to not receive problem return objects.
+* `2021-01-19`: more details for {GET-with-Body} and {DELETE-with-Body} (<<148>>).
+* `2020-09-29`: include models for headers to be included by reference in API definitions (<<183>>)
+* `2020-09-08`: add exception for legacy host names to <<224>>
+* `2020-08-25`: change <<240>> from {MUST} to {SHOULD}, explain exceptions
+* `2020-08-25`: add exception for `self` to <<143>> and <<134>>.
+* `2020-08-24`: change "{MUST} avoid trailing slashes" to <<136>>.
+* `2020-08-20`: change <<183>> from {MUST} to {SHOULD}, mention gateway-specific headers (which are not part of the public API).
+* `2020-06-30`: add details to <<114>>
+* `2020-05-19`: new sections about DELETE with query parameters and {DELETE-with-Body} in <<148>>.
+* `2020-02-06`: new rule <<241>>
+* `2020-02-05`: add Sunset header, clarify deprecation producedure (<<185>>, <<186>>, <<187>>, <<188>>, <<189>>, <<190>>, <<191>>)
+* `2020-01-21`: new rule <<240>> (as MUST, changed later to SHOULD)
+* `2020-01-15`: change "Warning" to "Deprecation" header in <<189>>, <<190>>.

scripts/changelog.sh

@@ -0,0 +1,177 @@
+#!/bin/bash
+
+# Generate changelog entries from git history using AI analysis
+# Usage: ./changelog.sh [OPTIONS] [YEAR|DATE]
+#
+# By default (no arguments):
+#   - Detects latest changelog entry date from chapters/changelog.adoc
+#   - Generates entries for commits since that date
+#   - Outputs filtered changelog entries only
+#
+# Options:
+#   --raw          Show full AI analysis output instead of filtered entries
+#   --update       Write new entries to chapters/changelog.adoc (prepend to rule-changes section)
+#   --since DATE   Use explicit date (format: YYYY-MM-DD) instead of auto-detecting
+#   --year YEAR    Generate for a specific year (format: YYYY)
+#
+# Examples:
+#   ./changelog.sh                     # Auto-detect and generate since last entry
+#   ./changelog.sh --raw               # Auto-detect with full output
+#   ./changelog.sh --update            # Auto-detect and update the changelog file
+#   ./changelog.sh --since 2025-01-01  # Generate since specific date
+#   ./changelog.sh --year 2025         # Generate for entire year 2025
+#   ./changelog.sh 2025 --raw          # Legacy: year as positional argument with --raw
+
+set -euo pipefail
+
+SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
+REPO_ROOT="$(dirname "$SCRIPT_DIR")"
+PROMPT_FILE="$SCRIPT_DIR/changelog.prompt"
+CHANGELOG_FILE="$REPO_ROOT/chapters/changelog.adoc"
+
+# Parse arguments
+MODE="auto"  # auto, year, since
+PARAM=""
+RAW_OUTPUT=false
+UPDATE_FILE=false
+
+# Handle legacy positional arguments first
+if [[ ${#@} -gt 0 ]] && [[ "$1" =~ ^[0-9]{4}$ ]]; then
+    MODE="year"
+    PARAM="$1"
+    shift
+fi
+
+# Parse remaining options
+while [[ ${#@} -gt 0 ]]; do
+    case "$1" in
+        --raw)
+            RAW_OUTPUT=true
+            ;;
+        --update)
+            UPDATE_FILE=true
+            ;;
+        --year)
+            MODE="year"
+            PARAM="${2:-}"
+            if [[ -z "$PARAM" ]]; then
+                echo "Error: --year requires a year argument (YYYY)" >&2
+                exit 1
+            fi
+            shift
+            ;;
+        --since)
+            MODE="since"
+            PARAM="${2:-}"
+            if [[ -z "$PARAM" ]]; then
+                echo "Error: --since requires a date argument (YYYY-MM-DD)" >&2
+                exit 1
+            fi
+            shift
+            ;;
+        *)
+            echo "Error: Unknown option: $1" >&2
+            exit 1
+            ;;
+    esac
+    shift
+done
+
+# Check dependencies
+if ! command -v zllm &> /dev/null; then
+    echo "Error: 'zllm' command not found. Please install zllm to use this script." >&2
+    exit 1
+fi
+
+if [[ ! -f "$PROMPT_FILE" ]]; then
+    echo "Error: Prompt file not found: $PROMPT_FILE" >&2
+    exit 1
+fi
+
+# Determine the date range for git log
+cd "$REPO_ROOT"
+
+case "$MODE" in
+    auto)
+        # Extract latest date from changelog.adoc
+        if [[ ! -f "$CHANGELOG_FILE" ]]; then
+            echo "Error: Changelog file not found: $CHANGELOG_FILE" >&2
+            exit 1
+        fi
+
+        # Look for first date entry after "== Rule Changes" section
+        LATEST_DATE=$(grep -oP "^\* \`\K[0-9]{4}-[0-9]{2}-[0-9]{2}" "$CHANGELOG_FILE" | head -1)
+
+        if [[ -z "$LATEST_DATE" ]]; then
+            echo "Error: Could not find any date entries in changelog" >&2
+            exit 1
+        fi
+
+        echo "Latest changelog entry: $LATEST_DATE" >&2
+        AFTER_DATE="$LATEST_DATE"
+        ;;
+    year)
+        if ! [[ "$PARAM" =~ ^[0-9]{4}$ ]]; then
+            echo "Error: Invalid year format. Expected YYYY, got: $PARAM" >&2
+            exit 1
+        fi
+        AFTER_DATE="$PARAM-01-01"
+        BEFORE_DATE="$PARAM-12-31"
+        ;;
+    since)
+        if ! [[ "$PARAM" =~ ^[0-9]{4}-[0-9]{2}-[0-9]{2}$ ]]; then
+            echo "Error: Invalid date format. Expected YYYY-MM-DD, got: $PARAM" >&2
+            exit 1
+        fi
+        AFTER_DATE="$PARAM"
+        ;;
+esac
+
+# Get git log with diffs
+if [[ -n "${BEFORE_DATE:-}" ]]; then
+    GIT_LOG=$(git log -p --after="$AFTER_DATE" --before="$BEFORE_DATE")
+else
+    GIT_LOG=$(git log -p --after="$AFTER_DATE")
+fi
+
+if [[ -z "$GIT_LOG" ]]; then
+    echo "No commits found since $AFTER_DATE" >&2
+    exit 0
+fi
+
+# Pipe prompt and git log through zllm
+OUTPUT=$(cat "$PROMPT_FILE" <(echo) <(echo "$GIT_LOG") | zllm)
+
+# Extract changelog entries (lines starting with '*')
+ENTRIES=$(echo "$OUTPUT" | grep '^\*' || true)
+
+# Output or update
+if [[ "$RAW_OUTPUT" == true ]]; then
+    echo "$OUTPUT"
+elif [[ "$UPDATE_FILE" == true ]]; then
+    if [[ -z "$ENTRIES" ]]; then
+        echo "No changelog entries generated. Not updating file." >&2
+        exit 0
+    fi
+
+    # Create temporary file with new entries inserted after "== Rule Changes" header
+    # Split file into: header + new entries + rest
+    HEADER_LINE=$(grep -n "^== Rule Changes$" "$CHANGELOG_FILE" | cut -d: -f1)
+
+    {
+        # Read file up to (but not including) "== Rule Changes"
+        head -n "$((HEADER_LINE - 1))" "$CHANGELOG_FILE"
+        # Add the header and blank line
+        echo "== Rule Changes"
+        echo
+        # Add new entries
+        echo "$ENTRIES"
+        # Add existing entries (skip "== Rule Changes" line and the blank line after it)
+        tail -n +"$((HEADER_LINE + 2))" "$CHANGELOG_FILE"
+    } > "$CHANGELOG_FILE.tmp"
+
+    mv "$CHANGELOG_FILE.tmp" "$CHANGELOG_FILE"
+    echo "Updated $CHANGELOG_FILE with new entries" >&2
+else
+    echo "$ENTRIES"
+fi