#!/bin/sh

# script/generate-release-notes: Generate release notes from conventional commits
#
# This script generates release notes by parsing conventional commits between git tags.
# It supports multiple backends for generation:
#
#   1. GitHub Copilot (VS Code Copilot CLI) - Intelligent, context-aware
#   2. git-cliff - Fast, template-based Rust tool
#   3. Manual parsing - Simple grep/awk fallback
#
# Usage:
#   ./scripts/generate-release-notes [FROM_TAG] [TO_TAG]
#   ./scripts/generate-release-notes v1.0.0 v1.1.0
#   ./scripts/generate-release-notes v1.0.0 HEAD
#   ./scripts/generate-release-notes               # Uses latest tag to HEAD
#
# Environment variables:
#   RELEASE_NOTES_BACKEND - Force specific backend: copilot, git-cliff, manual
#   USE_AI - Set to "false" to skip AI backends (for CI/CD)

set -e

cd "$(dirname "$0")/.."

# Colors for output
RED='\033[0;31m'
GREEN='\033[0;32m'
YELLOW='\033[1;33m'
BLUE='\033[0;34m'
NC='\033[0m' # No Color

# Detect if running in CI (suppress colored output to stdout)
if [ -n "$CI" ] || [ -n "$GITHUB_ACTIONS" ]; then
    # In CI, send info messages to stderr to keep release notes clean
    log_info() {
        echo "$@" >&2
    }
else
    # Local execution, show colored output
    log_info() {
        echo "$@"
    }
fi

# Configuration
BACKEND="${RELEASE_NOTES_BACKEND:-auto}"
USE_AI="${USE_AI:-true}"
GITHUB_REPO="${GITHUB_REPOSITORY:-jpawlowski/hass.tibber_prices}"

# Parse arguments
FROM_TAG="${1:-$(git describe --tags --abbrev=0 2>/dev/null || echo "")}"
TO_TAG="${2:-HEAD}"

if [ -z "$FROM_TAG" ]; then
    echo "${RED}Error: No tags found in repository${NC}" >&2
    echo "Usage: $0 [FROM_TAG] [TO_TAG]" >&2
    exit 1
fi

log_info "${BLUE}==> Generating release notes: ${FROM_TAG}..${TO_TAG}${NC}"
log_info ""

# Detect available backends
detect_backend() {
    if [ "$BACKEND" != "auto" ]; then
        echo "$BACKEND"
        return
    fi

    # Skip AI in CI/CD or if disabled
    if [ "$USE_AI" = "false" ] || [ -n "$CI" ] || [ -n "$GITHUB_ACTIONS" ]; then
        if command -v git-cliff >/dev/null 2>&1; then
            echo "git-cliff"
            return
        fi
        echo "manual"
        return
    fi

    # Check for GitHub Copilot CLI (AI-powered, best quality)
    if command -v copilot >/dev/null 2>&1; then
        echo "copilot"
        return
    fi

    # Check for git-cliff (fast and reliable)
    if command -v git-cliff >/dev/null 2>&1; then
        echo "git-cliff"
        return
    fi

    # Fallback to manual parsing
    echo "manual"
}

BACKEND=$(detect_backend)
log_info "${GREEN}Using backend: ${BACKEND}${NC}"
log_info ""

# Backend: GitHub Copilot CLI (AI-powered)
generate_with_copilot() {
    log_info "${BLUE}==> Generating with GitHub Copilot CLI (AI-powered)${NC}"
    log_info "${YELLOW}Note: This will use one premium request from your monthly quota${NC}"
    log_info ""

    # Get commit log for the range
    COMMITS=$(git log --pretty=format:"%h | %s%n%b%n---" "${FROM_TAG}..${TO_TAG}")

    if [ -z "$COMMITS" ]; then
        log_info "${YELLOW}No commits found between ${FROM_TAG} and ${TO_TAG}${NC}"
        exit 0
    fi

    # Create prompt for Copilot
    PROMPT="Generate release notes in GitHub-flavored Markdown from these conventional commits.

**Commits between ${FROM_TAG} and ${TO_TAG}:**

${COMMITS}

**Format Requirements:**
1. Parse conventional commit format: type(scope): description
2. Group by type with emoji headings:
   - 🎉 New Features (feat)
   - 🐛 Bug Fixes (fix)
   - 📚 Documentation (docs)
   - � Dependencies (chore(deps))
   - �🔧 Maintenance & Refactoring (refactor, chore)
   - 🧪 Testing (test)
3. **Smart grouping**: If multiple commits address the same logical change or feature:
   - Combine them into one release note entry
   - Link all related commits: ([hash1](url1), [hash2](url2))
   - Use a descriptive summary that captures the overall change
4. Extract 'Impact:' sections from commit bodies as user-friendly descriptions
5. Format each item as: - **scope**: Description ([hash](https://github.com/${GITHUB_REPO}/commit/hash))
6. Keep it concise, focus on user-visible changes
7. **Exclude from release notes**:
   - Manifest.json version bumps: chore(release): bump version
   - Development environment: feat/fix/chore(devcontainer), feat/fix/chore(vscode), feat/fix/chore(scripts), feat/fix/chore(dev-env)
   - CI/CD infrastructure: feat/fix/chore/ci(ci), feat/fix/chore/ci(workflow), feat/fix/chore/ci(actions)
8. **Include in release notes**:
   - Dependency updates: chore(deps) - these ARE relevant for users
   - Any user-facing changes regardless of scope
9. Output ONLY the markdown, no explanations

**Examples of smart grouping:**
- Multiple commits fixing the same bug → One entry with all commits
- Commits adding a feature incrementally → One entry describing the complete feature
- Related refactoring commits → One entry summarizing the improvement

Generate the release notes now:"

    # Save prompt to temp file for copilot
    TEMP_PROMPT=$(mktemp)
    echo "$PROMPT" > "$TEMP_PROMPT"

    # Call copilot CLI (it will handle authentication interactively)
    copilot < "$TEMP_PROMPT" || {
        echo ""
        log_info "${YELLOW}Warning: GitHub Copilot CLI failed or was not authenticated${NC}"
        log_info "${YELLOW}Falling back to git-cliff${NC}"
        rm -f "$TEMP_PROMPT"
        if command -v git-cliff >/dev/null 2>&1; then
            generate_with_gitcliff
        else
            generate_with_manual
        fi
        return
    }

    rm -f "$TEMP_PROMPT"
}

# Backend: git-cliff (template-based)
generate_with_gitcliff() {
    log_info "${BLUE}==> Generating with git-cliff${NC}"

    # Create temporary cliff.toml if not exists
    if [ ! -f "cliff.toml" ]; then
        cat > /tmp/cliff.toml <<'EOF'
[changelog]
header = ""
body = """
{% for group, commits in commits | group_by(attribute="group") %}
    ### {{ group | striptags | trim | upper_first }}
    {% for commit in commits %}
        - {% if commit.scope %}**{{ commit.scope }}**: {% endif %}{{ commit.message | upper_first }}\
          {% if commit.breaking %} [**BREAKING**]{% endif %}
    {% endfor %}
{% endfor %}
"""
trim = true

[git]
conventional_commits = true
filter_unconventional = false
split_commits = false
commit_parsers = [
    { message = "^feat", group = "🎉 New Features" },
    { message = "^fix", group = "🐛 Bug Fixes" },
    { message = "^doc", group = "📚 Documentation" },
    { message = "^perf", group = "⚡ Performance" },
    { message = "^refactor", group = "🔧 Maintenance & Refactoring" },
    { message = "^style", group = "🎨 Styling" },
    { message = "^test", group = "🧪 Testing" },
    { message = "^chore", group = "🔧 Maintenance & Refactoring" },
    { message = "^ci", group = "🔄 CI/CD" },
    { message = "^build", group = "📦 Build" },
]
EOF
        CLIFF_CONFIG="/tmp/cliff.toml"
    else
        CLIFF_CONFIG="cliff.toml"
    fi

    git-cliff --config "$CLIFF_CONFIG" "${FROM_TAG}..${TO_TAG}"

    if [ "$CLIFF_CONFIG" = "/tmp/cliff.toml" ]; then
        rm -f /tmp/cliff.toml
    fi
}

# Backend: Manual parsing (fallback)
generate_with_manual() {
    log_info "${BLUE}==> Generating with manual parsing${NC}"
    echo ""

    # Check if we have commits
    if ! git log --oneline "${FROM_TAG}..${TO_TAG}" >/dev/null 2>&1; then
        log_info "${YELLOW}No commits found between ${FROM_TAG} and ${TO_TAG}${NC}"
        exit 0
    fi

    # Create temporary files for each category
    TMPDIR=$(mktemp -d)
    FEAT_FILE="${TMPDIR}/feat"
    FIX_FILE="${TMPDIR}/fix"
    DOCS_FILE="${TMPDIR}/docs"
    REFACTOR_FILE="${TMPDIR}/refactor"
    TEST_FILE="${TMPDIR}/test"
    OTHER_FILE="${TMPDIR}/other"

    touch "$FEAT_FILE" "$FIX_FILE" "$DOCS_FILE" "$REFACTOR_FILE" "$TEST_FILE" "$OTHER_FILE"

    # Process commits
    git log --pretty=format:"%h %s" "${FROM_TAG}..${TO_TAG}" | while read -r hash subject; do
        # Simple type extraction (before colon)
        TYPE=""
        if echo "$subject" | grep -q '^feat'; then
            TYPE="feat"
        elif echo "$subject" | grep -q '^fix'; then
            TYPE="fix"
        elif echo "$subject" | grep -q '^docs'; then
            TYPE="docs"
        elif echo "$subject" | grep -q '^refactor\|^chore'; then
            TYPE="refactor"
        elif echo "$subject" | grep -q '^test'; then
            TYPE="test"
        else
            TYPE="other"
        fi

        # Create markdown line
        LINE="- ${subject} ([${hash}](https://github.com/jpawlowski/hass.tibber_prices/commit/${hash}))"

        # Append to appropriate file
        case "$TYPE" in
            feat)
                echo "$LINE" >> "$FEAT_FILE"
                ;;
            fix)
                echo "$LINE" >> "$FIX_FILE"
                ;;
            docs)
                echo "$LINE" >> "$DOCS_FILE"
                ;;
            refactor)
                echo "$LINE" >> "$REFACTOR_FILE"
                ;;
            test)
                echo "$LINE" >> "$TEST_FILE"
                ;;
            *)
                echo "$LINE" >> "$OTHER_FILE"
                ;;
        esac
    done

    # Output grouped by category
    if [ -s "$FEAT_FILE" ]; then
        echo "## 🎉 New Features"
        echo ""
        cat "$FEAT_FILE"
        echo ""
    fi

    if [ -s "$FIX_FILE" ]; then
        echo "## 🐛 Bug Fixes"
        echo ""
        cat "$FIX_FILE"
        echo ""
    fi

    if [ -s "$DOCS_FILE" ]; then
        echo "## 📚 Documentation"
        echo ""
        cat "$DOCS_FILE"
        echo ""
    fi

    if [ -s "$REFACTOR_FILE" ]; then
        echo "## 🔧 Maintenance & Refactoring"
        echo ""
        cat "$REFACTOR_FILE"
        echo ""
    fi

    if [ -s "$TEST_FILE" ]; then
        echo "## 🧪 Testing"
        echo ""
        cat "$TEST_FILE"
        echo ""
    fi

    if [ -s "$OTHER_FILE" ]; then
        echo "## 📝 Other Changes"
        echo ""
        cat "$OTHER_FILE"
        echo ""
    fi

    # Cleanup
    rm -rf "$TMPDIR"
}

# Execute based on backend
case "$BACKEND" in
    copilot)
        if ! command -v copilot >/dev/null 2>&1; then
            echo "${RED}Error: GitHub Copilot CLI not found${NC}"
            echo "Install: npm install -g @github/copilot"
            echo "See: https://github.com/github/copilot-cli"
            exit 1
        fi
        generate_with_copilot
        ;;
    git-cliff)
        if ! command -v git-cliff >/dev/null 2>&1; then
            echo "${RED}Error: git-cliff not found${NC}"
            echo "Install: https://git-cliff.org/docs/installation"
            exit 1
        fi
        generate_with_gitcliff
        ;;
    manual)
        generate_with_manual
        ;;
    *)
        echo "${RED}Error: Unknown backend: ${BACKEND}${NC}"
        echo "Valid backends: copilot, git-cliff, manual"
        exit 1
        ;;
esac

echo ""
log_info "${GREEN}==> Release notes generated successfully!${NC}"