#!/bin/bash
# Generate changelog from git history for Woodpecker CI releases
# Groups commits by conventional commit types (feat, fix, chore, refactor)
#
# Usage: ./generate-changelog.sh <tag> [output-file]
#   tag: Git tag to generate changelog for (e.g., v1.0.0)
#   output-file: Optional output file path (default: CHANGELOG.md)

set -e

# Check if tag argument is provided
if [ -z "$1" ]; then
  echo "Error: Tag argument required"
  echo "Usage: $0 <tag> [output-file]"
  exit 1
fi

TAG="$1"
OUTPUT_FILE="${2:-CHANGELOG.md}"

echo "Generating changelog for ${TAG}..."

# Get previous tag (if exists)
PREV_TAG=$(git describe --tags --abbrev=0 "${TAG}^" 2>/dev/null || echo "")

if [ -z "$PREV_TAG" ]; then
  echo "No previous tag found. This is the first release."
  # Get the first commit in the repository
  FIRST_COMMIT=$(git rev-list --max-parents=0 HEAD)
  COMMIT_RANGE="${FIRST_COMMIT}..${TAG}"
  echo "Generating changelog from first commit to ${TAG}"
else
  COMMIT_RANGE="${PREV_TAG}..${TAG}"
  echo "Generating changelog from ${PREV_TAG} to ${TAG}"
fi

# Initialize changelog file
echo "# Release ${TAG}" > "$OUTPUT_FILE"
echo "" >> "$OUTPUT_FILE"

if [ -z "$PREV_TAG" ]; then
  echo "First release of Worldhopper! 🎉" >> "$OUTPUT_FILE"
  echo "" >> "$OUTPUT_FILE"
fi

# Get all commits in range
COMMITS=$(git log "${COMMIT_RANGE}" --pretty=format:"%H|%s" 2>/dev/null || echo "")

if [ -z "$COMMITS" ]; then
  echo "No commits found in range" >> "$OUTPUT_FILE"
else
  # Arrays to hold categorized commits
  FEATURES=""
  FIXES=""
  CHORES=""
  REFACTORS=""
  OTHERS=""

  # Parse commits and categorize
  while IFS='|' read -r hash message; do
    # Skip empty lines
    [ -z "$hash" ] && continue

    case "$message" in
      feat:*|feat\(*)
        FEATURES="${FEATURES}- ${message#feat:} (${hash:0:7})\n"
        ;;
      fix:*|fix\(*)
        FIXES="${FIXES}- ${message#fix:} (${hash:0:7})\n"
        ;;
      chore:*|chore\(*)
        CHORES="${CHORES}- ${message#chore:} (${hash:0:7})\n"
        ;;
      refactor:*|refactor\(*)
        REFACTORS="${REFACTORS}- ${message#refactor:} (${hash:0:7})\n"
        ;;
      *)
        OTHERS="${OTHERS}- ${message} (${hash:0:7})\n"
        ;;
    esac
  done <<< "$COMMITS"

  # Write categorized sections
  if [ -n "$FEATURES" ]; then
    echo "## ✨ Features" >> "$OUTPUT_FILE"
    echo "" >> "$OUTPUT_FILE"
    echo -e "$FEATURES" >> "$OUTPUT_FILE"
  fi

  if [ -n "$FIXES" ]; then
    echo "## 🐛 Bug Fixes" >> "$OUTPUT_FILE"
    echo "" >> "$OUTPUT_FILE"
    echo -e "$FIXES" >> "$OUTPUT_FILE"
  fi

  if [ -n "$REFACTORS" ]; then
    echo "## ♻️ Refactoring" >> "$OUTPUT_FILE"
    echo "" >> "$OUTPUT_FILE"
    echo -e "$REFACTORS" >> "$OUTPUT_FILE"
  fi

  if [ -n "$CHORES" ]; then
    echo "## 🔧 Chores" >> "$OUTPUT_FILE"
    echo "" >> "$OUTPUT_FILE"
    echo -e "$CHORES" >> "$OUTPUT_FILE"
  fi

  if [ -n "$OTHERS" ]; then
    echo "## 📝 Other Changes" >> "$OUTPUT_FILE"
    echo "" >> "$OUTPUT_FILE"
    echo -e "$OTHERS" >> "$OUTPUT_FILE"
  fi
fi

echo "" >> "$OUTPUT_FILE"
echo "---" >> "$OUTPUT_FILE"

# Add full changelog link if we have git forge info
if [ -n "$CI_FORGE_URL" ] && [ -n "$CI_REPO" ]; then
  COMPARE_BASE="${PREV_TAG:-$(git rev-list --max-parents=0 HEAD | head -1)}"
  echo "**Full Changelog**: ${CI_FORGE_URL}/${CI_REPO}/compare/${COMPARE_BASE}...${TAG}" >> "$OUTPUT_FILE"
elif [ -n "$PREV_TAG" ]; then
  echo "**Commits**: \`git log ${PREV_TAG}..${TAG}\`" >> "$OUTPUT_FILE"
else
  echo "**First Release**" >> "$OUTPUT_FILE"
fi

echo ""
echo "Changelog generated successfully: ${OUTPUT_FILE}"
echo ""
cat "$OUTPUT_FILE"