#!/bin/bash
set -e

if [ -z "$GITEA_PAT" ]; then
  echo "No GITEA_PAT provided, skipping priority gate."
  exit 0
fi

if [ -z "$CURRENT_RUN_ID" ] || [ -z "$CURRENT_TARGET" ] || [ -z "$GITHUB_REPOSITORY" ]; then
  echo "Missing required environment variables. CURRENT_RUN_ID=$CURRENT_RUN_ID, CURRENT_TARGET=$CURRENT_TARGET, GITHUB_REPOSITORY=$GITHUB_REPOSITORY"
  # Don't fail the build just because target is empty (e.g. skip targets) or env vars are missing during PRs
  echo "Bypassing priority gate gracefully."
  exit 0
fi

declare -A PRIO=( ["production"]=40 ["staging"]=30 ["testing"]=20 ["branch"]=10 )
CURRENT_PRIO=${PRIO[$CURRENT_TARGET]:-0}

echo "Current Run: $CURRENT_RUN_ID, Target: $CURRENT_TARGET, Priority: $CURRENT_PRIO"

API_BASE="https://git.infra.mintel.me/api/v1/repos/$GITHUB_REPOSITORY/actions/runs"

# Fetch running and waiting workflows
LIMIT=50
RESPONSE=$(curl -s -H "Authorization: token $GITEA_PAT" "$API_BASE?limit=$LIMIT")

# Verify response is a valid JSON array
if ! echo "$RESPONSE" | jq -e 'type == "array"' >/dev/null 2>&1; then
  echo "Failed to parse API response from Gitea (not an array) or API error."
  echo "$RESPONSE"
  echo "Bypassing priority gate gracefully."
  exit 0
fi

# Use jq to extract running or waiting jobs that are NOT the current one
RUNS=$(echo "$RESPONSE" | jq -c '.[] | select(.id != '"$CURRENT_RUN_ID"') | select(.status == "running" or .status == "waiting")')

if [ -z "$RUNS" ]; then
  echo "No other running/waiting workflows found."
  exit 0
fi

while IFS= read -r run; do
  if [ -z "$run" ]; then continue; fi
  
  RUN_ID=$(echo "$run" | jq -r '.id')
  REF=$(echo "$run" | jq -r '.ref')
  REF_NAME=${REF#refs/tags/}
  REF_NAME=${REF_NAME#refs/heads/}

  # Determine target of the running workflow
  TARGET="branch"
  if [ "$REF" == "refs/heads/main" ] || [ "$REF_NAME" == "main" ]; then
    TARGET="testing"
  elif [[ "$REF" == refs/tags/* ]] || [[ "$REF" == refs/heads/v* ]]; then
    if [[ "$REF_NAME" =~ ^v[0-9]+\.[0-9]+\.[0-9]+$ ]]; then
      TARGET="production"
    else
      TARGET="staging"
    fi
  fi
  
  RUN_PRIO=${PRIO[$TARGET]:-0}
  
  echo "Found running workflow ID: $RUN_ID (Target: $TARGET, Priority: $RUN_PRIO)"
  
  if [ "$CURRENT_PRIO" -gt "$RUN_PRIO" ]; then
    echo "Current workflow has HIGHER priority ($CURRENT_PRIO > $RUN_PRIO). Canceling run $RUN_ID..."
    curl -s -X POST -H "Authorization: token $GITEA_PAT" "$API_BASE/$RUN_ID/cancel"
  elif [ "$CURRENT_PRIO" -lt "$RUN_PRIO" ]; then
    echo "Current workflow has LOWER priority ($CURRENT_PRIO < $RUN_PRIO). Aborting self."
    curl -s -X POST -H "Authorization: token $GITEA_PAT" "$API_BASE/$CURRENT_RUN_ID/cancel"
    echo "Waiting for Gitea to process cancellation..."
    sleep 15
    exit 0
  else
    # Equal priority: Newer wins
    if [ "$CURRENT_RUN_ID" -gt "$RUN_ID" ]; then
      echo "Equal priority, but current is newer. Canceling run $RUN_ID..."
      curl -s -X POST -H "Authorization: token $GITEA_PAT" "$API_BASE/$RUN_ID/cancel"
    else
      echo "Equal priority, but current is older. Aborting self."
      curl -s -X POST -H "Authorization: token $GITEA_PAT" "$API_BASE/$CURRENT_RUN_ID/cancel"
      echo "Waiting for Gitea to process cancellation..."
      sleep 15
      exit 0
    fi
  fi
done <<< "$RUNS"

echo "Priority gate cleared. Continuing deployment."