#!/bin/bash

# Semantic commit pattern
PATTERN='^(feat|fix|docs|style|refactor|test|perf|build|ci|chore|revert)(\([a-zA-Z0-9\._-]+\))?: .{1,}$'

# Pattern for merge commits from pull requests
PR_MERGE_PATTERN='^Merge pull request'

# Pattern for standard Git merge commits
GIT_MERGE_PATTERN='^Merge (branch|remote-tracking branch) .+ into .+$'

# Set text colors
RED='\033[0;31m'
GREEN='\033[0;32m'
YELLOW='\033[0;33m'
BLUE='\033[0;34m'
BOLD='\033[1m'
NC='\033[0m' # No Color

# Statistics tracking
INVALID_COMMITS=0
VALID_COMMITS=0
MERGE_COMMITS=0
TOTAL_COMMITS=0

# Draw box for statistics
draw_box() {
    local title="$1"
    local width=60
    local padding=$(((width - ${#title}) / 2))

    echo -e "${BOLD}┌$(printf '─%.0s' $(seq 1 $width))┐${NC}"
    echo -e "${BOLD}│$(printf ' %.0s' $(seq 1 $padding))$title$(printf ' %.0s' $(seq 1 $((width - padding - ${#title}))))│${NC}"
    echo -e "${BOLD}└$(printf '─%.0s' $(seq 1 $width))┘${NC}"
}

# Read stdin (format: <old-value> <new-value> <ref-name>)
while read -r OLD_REV NEW_REV REF_NAME; do
    # Skip if it's a branch deletion
    if [[ "$NEW_REV" = "0000000000000000000000000000000000000000" ]]; then
        continue
    fi

    # Handle new branch pushes differently
    if [[ "$OLD_REV" = "0000000000000000000000000000000000000000" ]]; then
        continue
    fi

    echo -e "${YELLOW}Checking commits in $REF_NAME${NC}"

    # Get branch stats from git (quietly)
    BRANCH_COMMITS=$(git rev-list --count "$REF_NAME" 2>/dev/null || echo "?")
    BRANCH_AGE=$(git log -1 --format="%cr" "$REF_NAME" 2>/dev/null || echo "unknown time ago")

    # Get all commit hashes between old and new revision
    COMMITS=$(git rev-list "$OLD_REV".."$NEW_REV")

    # Count how many commits we're validating
    COMMITS_TO_CHECK=$(echo "$COMMITS" | wc -l)
    if [ "$COMMITS_TO_CHECK" -eq 0 ]; then
        echo -e "${GREEN}No new commits to validate${NC}"
        continue
    else
        echo -e "${BLUE}Validating $COMMITS_TO_CHECK commit(s)${NC}"
    fi

    # Process each commit message silently
    for COMMIT in $COMMITS; do
        TOTAL_COMMITS=$((TOTAL_COMMITS + 1))
        COMMIT_MSG=$(git log --format=%B -n 1 "$COMMIT")
        COMMIT_SUBJECT=$(echo "$COMMIT_MSG" | head -n 1)
        PARENT_COUNT=$(git rev-list --parents -n 1 "$COMMIT" | awk '{print NF - 1}')

        # Process merge commits or regular commits
        if [[ $PARENT_COUNT -gt 1 ]] && (echo "$COMMIT_SUBJECT" | grep -E "$PR_MERGE_PATTERN" >/dev/null || echo "$COMMIT_SUBJECT" | grep -E "$GIT_MERGE_PATTERN" >/dev/null); then
            MERGE_COMMITS=$((MERGE_COMMITS + 1))
            continue
        fi

        # Validate commit message silently
        if ! [[ "$COMMIT_SUBJECT" =~ $PATTERN ]]; then
            INVALID_COMMITS=$((INVALID_COMMITS + 1))
        else
            VALID_COMMITS=$((VALID_COMMITS + 1))
        fi
    done

    # Display only the commit statistics box
    draw_box "COMMIT STATISTICS"
    echo -e "${BOLD}Branch information:${NC} $BRANCH_COMMITS total commits (created $BRANCH_AGE)"
    echo -e "${BOLD}Commits validated:${NC} $TOTAL_COMMITS"
    echo -e "${GREEN}Valid semantic commits:   ${NC} $VALID_COMMITS"
    echo -e "${BLUE}Merge commits:           ${NC} $MERGE_COMMITS"
    echo -e "${RED}Invalid commits:         ${NC} $INVALID_COMMITS"
    echo ""

    if [ $TOTAL_COMMITS -gt 0 ]; then
        VALID_PERCENT=$(((VALID_COMMITS + MERGE_COMMITS) * 100 / TOTAL_COMMITS))
        echo -e "${BOLD}Semantic compliance:${NC} $VALID_PERCENT%"

        # Print bar
        printf "["
        for ((i = 0; i < VALID_PERCENT / 5; i++)); do
            printf "${GREEN}#${NC}"
        done
        for ((i = VALID_PERCENT / 5; i < 20; i++)); do
            printf "${RED}.${NC}"
        done
        printf "] $VALID_PERCENT%%\n"
        echo ""
    fi
done

# If any commits were invalid, reject the push
if [[ $INVALID_COMMITS -gt 0 ]]; then
    echo -e "${RED}Push rejected: $INVALID_COMMITS commit(s) have invalid messages.${NC}"
    echo -e "${YELLOW}Please rewrite your commit messages to follow the semantic commit format:${NC}"
    echo "type(scope): message"
    exit 1
fi

exit 0