#!/bin/bash

# This script finds which Grafana releases include a specific commit.
# It checks both release branches and tags to determine:
# 1. Which previous releases include the commit
# 2. Which upcoming releases will include the commit
# 3. The first release that included the commit
#
# Usage: ./scripts/releasefinder.sh <commit-hash>
# The commit hash can be either:
# - Full hash (e.g., 1a2b3c4d5e6f7g8h9i0j1k2l3m4n5o6p7q8r9s0t)
# - Short hash (e.g., 1a2b3c4d)
#
# Example: ./scripts/releasefinder.sh a1b2c3d4e5f6
#
# If you get a "Permission denied" error, make the script executable with:
#   chmod +x scripts/releasefinder.sh

# Check if script is executable
if [ ! -x "$0" ]; then
    echo "Error: This script is not executable."
    echo "To fix this, run: chmod +x $0"
    echo "Then try running the script again."
    exit 1
fi

# Check if a commit hash was provided
if [ $# -ne 1 ]; then
    echo "Usage: $0 <commit-hash>"
    echo "The commit hash can be either:"
    echo "  - Full hash (e.g., 1a2b3c4d5e6f7g8h9i0j1k2l3m4n5o6p7q8r9s0t)"
    echo "  - Short hash (e.g., 1a2b3c4d)"
    echo "Example: $0 a1b2c3d4e5f6"
    exit 1
fi

COMMIT_HASH=$1

# Validate that the commit exists
if ! git cat-file -t "$COMMIT_HASH" >/dev/null 2>&1; then
    echo "Error: Commit $COMMIT_HASH not found in repository"
    echo "Make sure you've provided a valid commit hash (full or short)"
    exit 1
fi

echo "Fetching latest remote information..."
git fetch --all --tags --prune 2>/dev/null

echo "Finding release branches containing the commit..."
echo "Finding tags associated with the commit..."
echo

echo "Results for commit: $COMMIT_HASH"
echo "============================================="
echo

# Get commit details
echo "Commit details:"
echo "  Author: $(git log -1 --format="%an <%ae>" "$COMMIT_HASH")"
echo "  Date: $(git log -1 --format="%ad" --date=iso "$COMMIT_HASH")"

# Extract original PR number and create link
PR_NUMBER=$(git log -1 --pretty=format:"%B" "$COMMIT_HASH" | grep -o '#[0-9]\+' | head -n1 | tr -d '#')
if [ -n "$PR_NUMBER" ]; then
    # Extract PR title (first line of commit message)
    PR_TITLE=$(git log -1 --pretty=format:"%s" "$COMMIT_HASH")
    echo "  PR: #$PR_NUMBER - $PR_TITLE"
    echo "  Link: https://github.com/grafana/grafana/pull/$PR_NUMBER"
fi
echo

# Arrays to store results
declare -a release_branches=()
declare -a direct_tags=()
declare -a included_tags=()

# First check all release branches (including security releases)
for branch in $(git branch -r | grep -E 'origin/release-[0-9]+\.[0-9]+\.[0-9]+(\+security-[0-9]{2})?$' | sed 's/origin\///'); do
    # Check if the commit is in this branch's history
    if git merge-base --is-ancestor "$COMMIT_HASH" "origin/$branch" 2>/dev/null; then
        release_branches+=("$branch")
    fi
done

# Then check all version tags (including security releases)
for tag in $(git tag | sort -V); do
    # Skip non-version tags
    if ! [[ $tag =~ ^v[0-9]+\.[0-9]+\.[0-9]+(\+security-[0-9]{2})?$ ]]; then
        continue
    fi
    
    # Check if the commit is in this tag
    if git merge-base --is-ancestor "$COMMIT_HASH" "$tag" 2>/dev/null; then
        # If this is the first tag containing the commit, it's the initial release tag
        if [ ${#direct_tags[@]} -eq 0 ]; then
            direct_tags+=("$tag")
        else
            included_tags+=("$tag")
        fi
    fi
done

# Print previous releases if they exist
if [ ${#direct_tags[@]} -gt 0 ] || [ ${#included_tags[@]} -gt 0 ]; then
    echo "This commit has been included in these PREVIOUS on-prem releases:"
    # Get all tags sorted
    readarray -t all_tags < <(printf "%s\n" "${direct_tags[@]}" "${included_tags[@]}" | sort -V)
    # Get the first release
    first_release="${all_tags[0]}"
    # Print all tags with annotation for the first release
    for tag in "${all_tags[@]}"; do
        if [ "$tag" = "$first_release" ]; then
            echo "  - $tag (first release)"
        else
            echo "  - $tag"
        fi
    done
    echo
    echo "Note: This code may have been backported to previous release branches. Please check the original PR for backport information."
    echo
fi

# Print upcoming releases
if [ ${#release_branches[@]} -eq 0 ]; then
    echo "  This commit is not yet included in any release branches."
    echo "  The corresponding release branch has likely not been created yet."
else
    echo "This commit will be included in these UPCOMING on-prem releases:"
    for branch in "${release_branches[@]}"; do
        # Convert branch name to tag format (e.g., release-11.5.0 -> v11.5.0)
        tag_version="v${branch#release-}"
        # Only show branches that don't have a corresponding tag yet
        if ! git tag | grep -q "^$tag_version$"; then
            echo "  - $tag_version"
        fi
    done | sort -V
fi
echo