#!/bin/bash
# Script: validate_input.sh
# Description: Validates prerequisites and input parameters for building and pushing a Docker image.
# This script ensures that Docker, Docker Buildx, and input variables (architectures, tags, image name, registry URL)
# meet the required criteria. If any check fails, the script provides informative error messages and exits.

# Exit immediately if a command exits with a non-zero status.
set -e

echo "============================================"
echo "Starting Validation Script"
echo "============================================"

# ---------------------------- Docker Installation --------------------------- #
echo "🔍 Checking Docker installation..."
if docker --version >/dev/null 2>&1; then
    DOCKER_VERSION=$(docker --version)
    echo "✅ Docker is installed: $DOCKER_VERSION"
else
    echo "❌ Docker is not installed."
    echo "ℹ️ Please install Docker from: https://docs.docker.com/get-docker/"
    exit 1
fi

# ---------------------------- Buildx Installation --------------------------- #
echo "🔍 Checking Docker Buildx installation..."
if docker buildx version >/dev/null 2>&1; then
    BUILDX_VERSION=$(docker buildx version)
    echo "✅ Docker Buildx is installed: $BUILDX_VERSION"
else
    echo "❌ Docker Buildx is not installed."
    echo "ℹ️ Please install Docker Buildx. See: https://docs.docker.com/buildx/working-with-buildx/"
    exit 1
fi

# ---------------------------- Validate Architectures --------------------------- #
echo "🔍 Validating architectures..."
for arch in $ARCHITECTURES; do
    echo "→ Checking architecture: $arch"
    if [[ $VALID_ARCHITECTURES != *"$arch"* ]]; then
        echo "❌ Invalid architecture detected: $arch"
        echo "ℹ️ Allowed architectures are: $VALID_ARCHITECTURES"
        exit 1
    fi
done
echo "✅ All specified architectures are valid."

# ---------------------------- Validate Tags --------------------------- #
echo "🔍 Validating tags..."

# Ensure tags are lowercase.
if sh ./ensure_lowercase.sh "Tag" $TAGS; then
    echo "✅ All tags are lowercase."
else
    echo "❌ One or more tags are not lowercase. Please update the tags."
    exit 1
fi

# Ensure tags do not contain spaces.
if sh ./ensure_no_spaces.sh "Tag" $TAGS; then
    echo "✅ Tags do not contain spaces."
else
    echo "❌ One or more tags contain spaces. Please update the tags."
    exit 1
fi

# ---------------------------- Validate Image Name --------------------------- #
if [ "$NAME" != "auto" ]; then
    echo "🔍 Validating image name..."
    # Ensure image name is lowercase.
    if sh ./ensure_lowercase.sh "Name" $NAME; then
        echo "✅ Image name is lowercase."
    else
        echo "❌ Image name is not lowercase. Please update the name."
        exit 1
    fi

    # Ensure image name does not contain spaces.
    if sh ./ensure_no_spaces.sh "Name" $NAME; then
        echo "✅ Image name does not contain spaces."
    else
        echo "❌ Image name contains spaces. Please update the name."
        exit 1
    fi
else
    echo "ℹ️ Image name is set to auto-detect."
fi

# ---------------------------- Validate Registry URL --------------------------- #
echo "🔍 Validating Registry URL..."
# Ensure Registry URL does not contain spaces.
if sh ./ensure_no_spaces.sh "Registry URL" $REGISTRY_URL; then
    echo "✅ Registry URL does not contain spaces."
else
    echo "❌ Registry URL contains spaces. Please update the URL."
    exit 1
fi

# Ensure Registry URL is lowercase.
if sh ./ensure_lowercase.sh "Registry URL" $REGISTRY_URL; then
    echo "✅ Registry URL is lowercase."
else
    echo "❌ Registry URL is not lowercase. Please update the URL."
    exit 1
fi

# Ensure Registry URL starts with "https://"
if [[ $REGISTRY_URL != https://* ]]; then
    echo "❌ Invalid Registry URL: $REGISTRY_URL"
    echo "ℹ️ Registry URL must start with 'https://'"
    exit 1
fi
echo "✅ Registry URL starts with 'https://'"

# Check if Registry URL is reachable.
echo "🔍 Checking if Registry URL is reachable..."
if curl -s --head "$REGISTRY_URL" | head -n 1 | grep "HTTP/[12]\.[0-9] [23].." >/dev/null; then
    echo "✅ Registry URL is reachable: $REGISTRY_URL"
else
    echo "❌ Registry URL is not reachable: $REGISTRY_URL"
    echo "ℹ️ Please verify the URL and check your network connection."
    exit 1
fi

echo "============================================"
echo "All validations passed successfully!"
echo "============================================"