#!/bin/bash

source ./send_email.sh

# OAuth 2.0 configuration
CLIENT_ID=""
CLIENT_SECRET=""
REDIRECT_URI="http://localhost:3000/api/xoauth/callback"
AUTH_URL="https://login.xero.com/identity/connect/authorize"
TOKEN_URL="https://identity.xero.com/connect/token"
SCOPES="openid profile email accounting.attachments.read accounting.budgets.read accounting.contacts.read accounting.journals.read accounting.reports.read accounting.reports.tenninetynine.read accounting.settings.read accounting.transactions.read assets.read offline_access"

REDIS_URL=""

save_tokens_to_redis() {
    local tokens="$1"
    /usr/local/bin/redis-cli -u "$REDIS_URL" SET xero_tokens "$tokens"
}

save_state_to_redis() {
    local state="$1"
    /usr/local/bin/redis-cli -u "$REDIS_URL" SET xero_state:$state "$state"
}

get_tokens_from_redis() {
    /usr/local/bin/redis-cli -u "$REDIS_URL" GET xero_tokens
}

get_state_from_redis() {
    local state="$1"
    /usr/local/bin/redis-cli -u "$REDIS_URL" GET xero_state:$state
}

generate_auth_url() {
    STATE=$(openssl rand -hex 16)
    AUTH_REQUEST_URL="${AUTH_URL}?response_type=code&client_id=${CLIENT_ID}&redirect_uri=${REDIRECT_URI}&scope=${SCOPES}&state=${STATE}"
    save_state_to_redis "$STATE"
    echo "$AUTH_REQUEST_URL"
}

refresh_token() {
    local refresh_token="$1"
    TOKEN_RESPONSE=$(curl -s -X POST ${TOKEN_URL} \
         -H "Content-Type: application/x-www-form-urlencoded" \
         -d "grant_type=refresh_token" \
         -d "refresh_token=${refresh_token}" \
         -d "client_id=${CLIENT_ID}" \
         -d "client_secret=${CLIENT_SECRET}")

    if echo "$TOKEN_RESPONSE" | jq -e '.access_token' > /dev/null; then
        echo "Token refreshed successfully."
        save_tokens_to_redis "$TOKEN_RESPONSE"
        echo "New tokens saved to Redis."
    else
        echo "Error refreshing token. Response:"
        echo "$TOKEN_RESPONSE"
        AUTH_URL=$(generate_auth_url)
        AUTH_URL=$(echo "$AUTH_URL" | sed 's/^OK[[:space:]]*//' | tr -d '\n')
        TEXT_MESSAGE="Token refresh failed. Please re-authorize: $AUTH_URL"
        HTML_MESSAGE="Token refresh failed. Please <a href=\"$AUTH_URL\">re-authorize</a>"
        send_email "$TEXT_MESSAGE" "$HTML_MESSAGE"
        exit 1
    fi
}

exchange_code_for_tokens() {
    local auth_code="$1"
    TOKEN_RESPONSE=$(curl -s -X POST ${TOKEN_URL} \
         -H "Content-Type: application/x-www-form-urlencoded" \
         -d "grant_type=authorization_code" \
         -d "code=${auth_code}" \
         -d "redirect_uri=${REDIRECT_URI}" \
         -d "client_id=${CLIENT_ID}" \
         -d "client_secret=${CLIENT_SECRET}")

    if echo "$TOKEN_RESPONSE" | jq -e '.access_token' > /dev/null; then
        echo "Authorization code exchanged successfully."
        save_tokens_to_redis "$TOKEN_RESPONSE"
        echo "Tokens saved to Redis."
    else
        echo "Error exchanging authorization code. Response:"
        echo "$TOKEN_RESPONSE"
        exit 1
    fi
}

case "$1" in
    --refresh)
        echo "Refreshing token..."
        STORED_TOKENS=$(get_tokens_from_redis)
        REFRESH_TOKEN=$(echo $STORED_TOKENS | jq -r '.refresh_token')
        if [ -z "$REFRESH_TOKEN" ]; then
            echo "Error: Refresh token not found in Redis"
            AUTH_URL=$(generate_auth_url)
            AUTH_URL=$(echo "$AUTH_URL" | sed 's/^OK[[:space:]]*//' | tr -d '\n')
            TEXT_MESSAGE="Refresh token not found in Redis: $REDIS_URL. Please re-authorize: $AUTH_URL"
            HTML_MESSAGE="Refresh token not found in Redis: $REDIS_URL. Please <a href=\"$AUTH_URL\">re-authorize</a>"
            send_email "$TEXT_MESSAGE" "$HTML_MESSAGE"
            exit 1
        fi
        refresh_token "$REFRESH_TOKEN"
        ;;
    --code)
        if [ -z "$2" ]; then
            echo "Error: Authorization code not provided"
            exit 1
        fi
        echo "Exchanging authorization code for tokens..."
        exchange_code_for_tokens "$2"
        ;;
    "")
        # Generate a random state value
        STATE=$(openssl rand -hex 16)
        # Construct the authorization URL
        AUTH_REQUEST_URL=$(generate_auth_url)
        echo "Please visit this URL in a browser on your local machine to authorize the application:"
        echo $AUTH_REQUEST_URL
        echo
        echo "After authorization, you will be redirected to a URL starting with $REDIRECT_URI"
        echo "Look for the 'code' parameter in this URL."
        echo
        # Wait for the authorization code
        read -p "Enter the authorization code from the redirect URL: " AUTH_CODE
        exchange_code_for_tokens "$AUTH_CODE"
        ;;
    *)
        echo "Usage: $0 [--refresh | --code <authorization_code>]"
        exit 1
        ;;
esac

# Use the new access token to update configuration
STORED_TOKENS=$(get_tokens_from_redis)
NEW_ACCESS_TOKEN=$(echo $STORED_TOKENS | jq -r '.access_token')

CURL_RESPONSE=$(curl --request PATCH \
 --url 'http://localhost:8000/api/public/v1/sources/<source_id>' \
 --header 'accept: application/json' \
 --header 'authorization: Basic base64(username:password)' \
 --header 'Content-Type: application/json' \
 --data "{
   \"configuration\": {
     \"credentials\": {
       \"access_token\": \"$NEW_ACCESS_TOKEN\"
     }
   }
 }")

echo "CURL Response:"
echo "$CURL_RESPONSE"

if echo "$CURL_RESPONSE" | jq -e '.sourceId' > /dev/null; then
    echo "Configuration updated successfully."
    echo "Updated source details:"
    echo "$CURL_RESPONSE" | jq '.'
else
    echo "Error updating configuration. Response:"
    echo "$CURL_RESPONSE"
    send_email "Error updating configuration: $CURL_RESPONSE" "Error updating configuration: $CURL_RESPONSE"
fi