#!/usr/bin/env bash

set -euo pipefail

TARGET_BRANCH="main"

# Make sure we are in a git repo
if ! git rev-parse --git-dir > /dev/null 2>&1; then
    echo "❌ Not a git repository"
    exit 1
fi

# If this is a shallow clone, fetch enough history to compute merge bases
if git rev-parse --is-shallow-repository > /dev/null 2>&1 && git rev-parse --is-shallow-repository | grep -q true; then
    echo "🔄 Repository is shallow; fetching full history to enable merging…"
    git fetch --unshallow || git fetch --deepen=100000
fi

# Get list of open, non-draft PR numbers via GitHub API
echo "🔍 Fetching open PRs..."
mapfile -t PRS < <(curl -s "https://api.github.com/repos/alexbelgium/BirdNET-Pi/pulls?state=open&per_page=100" \
    | jq -r '.[] | select(.draft==false) | .number')

if [[ ${#PRS[@]} -eq 0 ]]; then
    echo "✅ No open non-draft PRs found."
    exit 0
fi

echo "Found PRs: ${PRS[*]}"

# Update local repo
git fetch origin
git checkout "$TARGET_BRANCH"
git pull origin "$TARGET_BRANCH"

# Merge each PR
for pr in "${PRS[@]}"; do
    echo "=== Merging PR #$pr ==="

    # Fetch PR branch from GitHub refs
    git fetch origin pull/"$pr"/head:pr-"$pr"

    # Merge into target branch, no fast-forward (like GitHub)
    if ! git merge --no-ff --no-edit "pr-$pr"; then
        echo "⚠️ Merge conflict in PR #$pr."
        echo "   Resolve manually, then run: git merge --continue"
        echo "   After resolving, re-run this script to finish remaining PRs."
        exit 1
    fi
done

echo "✅ All open non-draft PRs merged into $TARGET_BRANCH"