#!/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 CLI - Intelligent, context-aware (uses premium quota)
#   2. git-cliff - Fast, template-based Rust tool
#   3. Manual parsing - Simple grep/awk fallback
#
# Auto-update feature:
#   If a GitHub release exists for TO_TAG, the script will automatically offer
#   to update the release notes on GitHub (interactive prompt, local only).
#
# 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
#
#   # Interactive update of existing release:
#   ./scripts/generate-release-notes v0.2.0 v0.3.0
#   # → Generates notes
#   # → Detects release exists
#   # → Offers to update: [y/N]
#
# 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 with file statistics
    # This helps the AI understand which commits touched which files
    COMMITS=$(git log --pretty=format:"%h | %s%n%b%n" --stat --compact-summary "${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="You are tasked with generating professional release notes in GitHub-flavored Markdown from conventional commits.

**CRITICAL Format Requirements:**

1. **START with a single-line title using '# ' (H1 heading):**
   - Analyze ALL commits and create a SHORT, descriptive title (max 5-7 words)

   **HOW TO CHOOSE THE TITLE:**
   Step 1: Scan commit scopes and identify USER-FACING changes:
     - feat(sensors): ✅ User feature (they see new sensors)
     - feat(config_flow): ✅ User feature (they use config UI)
     - feat(services): ✅ User feature (they call services)
     - fix(translations): ✅ User fix (they see corrected text)
     - feat(release): ❌ Developer tool (users don't see this)
     - feat(ci): ❌ Infrastructure (users don't care)
     - docs: ❌ Documentation (nice but not a feature)

   Step 2: Among user-facing changes, prioritize by impact:
     - New sensor types > Config improvements > Bug fixes > Translations
     - Multiple related sensors = name the feature domain (e.g., \"Price Volatility Analysis\")
     - Major config flow changes = \"Enhanced Configuration Experience\"

   Step 3: Ignore developer/internal changes for title selection:
     - Even if there are 10 release/ci/docs commits, they don't appear in title
     - Title must reflect what USERS experience when they upgrade

   **EXAMPLE DECISION PROCESS:**
   Given these commits:
     - feat(sensors): Add 4 volatility sensors with classification
     - feat(release): Add automated release notes generation
     - fix(translations): Fix hassfest validation errors
     - docs: Restructure documentation

   WRONG title: \"Release Automation & Documentation\" (developer-focused!)
   RIGHT title: \"Price Volatility Analysis Features\" (user sees new sensors!)

   **GOOD TITLES (user-focused):**
   - \"# Advanced Price Analysis Features\" (new sensors = user feature)
   - \"# Enhanced Configuration Experience\" (config flow = user-facing)
   - \"# Improved Reliability & Performance\" (stability = user benefit)

   **BAD TITLES (avoid these):**
   - \"# Release Automation\" (developers don't read release notes!)
   - \"# Developer Experience\" (not user-facing!)
   - \"# New Features & Bug Fixes\" (boring, says nothing)

   Keep it exciting but professional. Do NOT include version number.

2. **After title, use '### ' (H3 headings) for sections:**
   - ### 🎉 New Features (for feat commits)
   - ### 🐛 Bug Fixes (for fix commits)
   - ### 📚 Documentation (for docs commits)
   - ### 📦 Dependencies (for chore(deps) commits)
   - ### 🔧 Maintenance & Refactoring (for refactor/chore commits)
   - ### 🧪 Testing (for test commits)

3. **Smart grouping**: If multiple commits address the same logical change:
   - 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. **Exclude from release notes (but still consider for context):**
   - Manifest.json version bumps: chore(release): bump version
   - Development environment: feat/fix/chore(devcontainer), feat/fix/chore(vscode), feat/fix/chore(scripts)
   - CI/CD infrastructure: feat/fix/chore/ci(ci), feat/fix/chore(workflow), feat/fix/chore(actions)
   - IMPORTANT: These should NEVER influence the title choice, even if they're the majority!

7. **Include in release notes (these CAN influence title):**
   - Dependency updates: chore(deps) - these ARE relevant for users
   - Any user-facing changes regardless of scope (sensors, config, services, binary_sensor, etc.)
   - Bug fixes that users experience (translations, api, coordinator, etc.)

8. **Understanding the file paths (use this to assess importance):**
   - custom_components/tibber_prices/sensor/ = User-facing sensors (HIGH priority for title)
   - custom_components/tibber_prices/binary_sensor.py = User-facing binary sensors (HIGH priority)
   - custom_components/tibber_prices/config_flow.py = User-facing configuration (HIGH priority)
   - custom_components/tibber_prices/services.py = User-facing services (HIGH priority)
   - custom_components/tibber_prices/translations/*.json = User-facing translations (MEDIUM priority)
   - scripts/ = Developer tools (LOW priority, exclude from title)
   - .github/workflows/ = CI/CD automation (LOW priority, exclude from title)
   - docs/ = Documentation (LOW priority, exclude from title)

   **Key insight:** Large changes (100+ lines) in custom_components/tibber_prices/ are usually important user features!

9. **Output structure example:**
   # Title Here

   ### 🎉 New Features

   - **scope**: description ([abc123](url))

   ### 🐛 Bug Fixes
   ...

---

**Now, here are the commits to analyze (between ${FROM_TAG} and ${TO_TAG}):**

${COMMITS}

---

**Generate the release notes now. Start with '# ' title, then use '### ' for sections.**

**IMPORTANT: Output ONLY the release notes in Markdown format. Do NOT include:**
- Explanations or rationale for your choices
- Meta-commentary about the process
- Analysis of why you chose the title
- Any text after the last release note section

End the output after the last release note item. Nothing more."

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

    # Use Claude Haiku 4.5 for faster, cheaper generation (same quality for structured tasks)
    # Can override with: COPILOT_MODEL=claude-sonnet-4.5 ./scripts/generate-release-notes
    COPILOT_MODEL="${COPILOT_MODEL:-claude-haiku-4.5}"

    # Call copilot CLI (it will handle authentication interactively)
    copilot --model "$COPILOT_MODEL" < "$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"
}

# ============================================================================
# Check if auto-update is possible (before generation)
# ============================================================================

AUTO_UPDATE_AVAILABLE=false
CURRENT_TITLE=""
CURRENT_URL=""

if [ -z "$CI" ] && [ -z "$GITHUB_ACTIONS" ] && command -v gh >/dev/null 2>&1 && [ "$TO_TAG" != "HEAD" ]; then
    # Check if TO_TAG is a valid tag and release exists
    if git rev-parse "$TO_TAG" >/dev/null 2>&1 && gh release view "$TO_TAG" >/dev/null 2>&1; then
        AUTO_UPDATE_AVAILABLE=true
        CURRENT_TITLE=$(gh release view "$TO_TAG" --json name --jq '.name' 2>/dev/null || echo "$TO_TAG")
        CURRENT_URL=$(gh release view "$TO_TAG" --json url --jq '.url' 2>/dev/null || echo "")
    fi
fi

# ============================================================================
# Generate release notes (only once)
# ============================================================================

# Validate backend availability
case "$BACKEND" in
    copilot)
        if ! command -v copilot >/dev/null 2>&1; then
            echo "${RED}Error: GitHub Copilot CLI not found${NC}" >&2
            echo "Install: npm install -g @github/copilot" >&2
            echo "See: https://github.com/github/copilot-cli" >&2
            exit 1
        fi
        ;;
    git-cliff)
        if ! command -v git-cliff >/dev/null 2>&1; then
            echo "${RED}Error: git-cliff not found${NC}" >&2
            echo "Install: https://git-cliff.org/docs/installation" >&2
            exit 1
        fi
        ;;
esac

# Generate to temp file if auto-update is possible, else stdout
if [ "$AUTO_UPDATE_AVAILABLE" = "true" ]; then
    TEMP_NOTES=$(mktemp)
    case "$BACKEND" in
        copilot)
            generate_with_copilot > "$TEMP_NOTES"
            ;;
        git-cliff)
            generate_with_gitcliff > "$TEMP_NOTES"
            ;;
        manual)
            generate_with_manual > "$TEMP_NOTES"
            ;;
    esac
else
    # No auto-update, just output to stdout
    case "$BACKEND" in
        copilot)
            generate_with_copilot
            ;;
        git-cliff)
            generate_with_gitcliff
            ;;
        manual)
            generate_with_manual
            ;;
    esac

    echo "" >&2
    log_info "${GREEN}==> Release notes generated successfully!${NC}"
    exit 0
fi

# ============================================================================
# Auto-update existing GitHub release
# ============================================================================

# Extract title and body from generated notes
# Title is the first line starting with '# ' (H1)
# Body is everything after the first blank line following the title
EXTRACTED_TITLE=""
NOTES_BODY=""

# Find the first line that starts with '# ' (skip any metadata before it)
TITLE_LINE_NUM=$(grep -n '^# ' "$TEMP_NOTES" | head -n 1 | cut -d: -f1)

if [ -n "$TITLE_LINE_NUM" ]; then
    # Extract title (remove '# ' prefix from that specific line)
    FIRST_TITLE_LINE=$(sed -n "${TITLE_LINE_NUM}p" "$TEMP_NOTES")
    EXTRACTED_TITLE=$(echo "$FIRST_TITLE_LINE" | sed 's/^# //')
    # Body starts from the line after the title
    BODY_START_LINE=$((TITLE_LINE_NUM + 1))
    NOTES_BODY=$(tail -n +$BODY_START_LINE "$TEMP_NOTES" | sed '1{/^$/d;}')
else
    # No H1 title found, use entire content as body
    NOTES_BODY=$(cat "$TEMP_NOTES")
fi

# Generate final title for GitHub release
if [ -n "$EXTRACTED_TITLE" ]; then
    # AI provided a title, prepend version tag
    RELEASE_TITLE="$TO_TAG - $EXTRACTED_TITLE"
else
    # Fallback: Keep current title if it looks meaningful
    # (more than just the tag itself)
    RELEASE_TITLE="$CURRENT_TITLE"
    if [ "$RELEASE_TITLE" = "$TO_TAG" ]; then
        # Current title is just the tag, generate from commit analysis
        # This is the git-cliff style fallback (simple but functional)
        FEAT_COUNT=$(echo "$NOTES_BODY" | grep -c "^### 🎉 New Features" || true)
        FIX_COUNT=$(echo "$NOTES_BODY" | grep -c "^### 🐛 Bug Fixes" || true)
        DOCS_COUNT=$(echo "$NOTES_BODY" | grep -c "^### 📚 Documentation" || true)

        if [ "$FEAT_COUNT" -gt 0 ] && [ "$FIX_COUNT" -gt 0 ]; then
            RELEASE_TITLE="$TO_TAG - New Features & Bug Fixes"
        elif [ "$FEAT_COUNT" -gt 0 ]; then
            RELEASE_TITLE="$TO_TAG - New Features"
        elif [ "$FIX_COUNT" -gt 0 ]; then
            RELEASE_TITLE="$TO_TAG - Bug Fixes"
        elif [ "$DOCS_COUNT" -gt 0 ]; then
            RELEASE_TITLE="$TO_TAG - Documentation Updates"
        else
            RELEASE_TITLE="$TO_TAG - Updates"
        fi
    fi
fi

# Save body (without H1 title) to temp file for GitHub
TEMP_BODY=$(mktemp)
echo "$NOTES_BODY" > "$TEMP_BODY"

# Show the generated notes (with title for preview)
if [ -n "$EXTRACTED_TITLE" ]; then
    echo "# $EXTRACTED_TITLE"
    echo ""
fi
cat "$TEMP_BODY"

echo "" >&2
log_info "${GREEN}==> Release notes generated successfully!${NC}"
echo "" >&2
log_info "${BLUE}═══════════════════════════════════════════════════════════════${NC}"
log_info "A GitHub release exists for ${CYAN}$TO_TAG${NC}"
log_info "Current title: ${CYAN}$CURRENT_TITLE${NC}"
log_info "New title: ${CYAN}$RELEASE_TITLE${NC}"
if [ -n "$CURRENT_URL" ]; then
    log_info "URL: ${CYAN}$CURRENT_URL${NC}"
fi
log_info "${BLUE}═══════════════════════════════════════════════════════════════${NC}"
echo "" >&2

printf "${YELLOW}Do you want to update the release notes on GitHub? [y/N]:${NC} " >&2
read -r UPDATE_RELEASE

if [ "$UPDATE_RELEASE" = "y" ] || [ "$UPDATE_RELEASE" = "Y" ]; then
    log_info "Updating release $TO_TAG on GitHub..."
    log_info "Title: ${CYAN}$RELEASE_TITLE${NC}"

    # Update release with both title and body
    if gh release edit "$TO_TAG" --title "$RELEASE_TITLE" --notes-file "$TEMP_BODY" 2>&1 >&2; then
        echo "" >&2
        log_info "${GREEN}✓ Release notes updated successfully!${NC}"
        if [ -n "$CURRENT_URL" ]; then
            log_info "View at: ${CYAN}$CURRENT_URL${NC}"
        fi
    else
        echo "" >&2
        log_info "${RED}✗ Failed to update release${NC}"
        log_info "You can manually update with:"
        echo "  ${CYAN}gh release edit $TO_TAG --notes-file -${NC} < notes.md" >&2
    fi
else
    log_info "Skipped release update"
    log_info "You can update manually later with:"
    echo "  ${CYAN}./scripts/generate-release-notes $FROM_TAG $TO_TAG | gh release edit $TO_TAG --notes-file -${NC}" >&2
fi

rm -f "$TEMP_NOTES" "$TEMP_BODY"
    exit 0
fi

# If no auto-update, just show success message
echo ""
log_info "${GREEN}==> Release notes generated successfully!${NC}"