#!/usr/bin/env bash

check_kubectl() {
    if ! command -v kubectl &>/dev/null; then
        echo "Error: kubectl is not installed or not in PATH" >&2
        exit 1
    fi
    log_info "kubectl found at $(command -v kubectl)"
}

VERBOSE=0

log_debug() { [[ $VERBOSE -ge 3 ]] && echo "[DEBUG] $*" || true; }
log_verbose() { [[ $VERBOSE -ge 2 ]] && echo "[VERBOSE] $*" || true; }
log_info() { [[ $VERBOSE -ge 1 ]] && echo "[INFO] $*" || true; }
log_error() { echo "[ERROR] $*" >&2; }

usage() {
    cat <<EOF
Usage: $(basename "$0") [OPTIONS] [VERSION]

Upgrade ArgoCD to a new version. Requires an existing ArgoCD installation.

Examples:
  $(basename "$0")                # queries the current argo version and tries to update to the immediate newest version
  $(basename "$0") v4.3.0        # incrementally update to target version

Options:
  -h, --help      Show this help message
  --dry-run       Show what would be done without making changes
  -v              Verbose output (info level)
  -vv             More verbose output (info + verbose level)
  -vvv            Debug output (all log levels)
EOF
}

DRY_RUN=false

while [[ $# -gt 0 ]]; do
    case "$1" in
        -h|--help)
            usage
            exit 0
            ;;
        --dry-run)
            DRY_RUN=true
            shift
            ;;
        -v|-vv|-vvv)
            case "$1" in
                -v)   VERBOSE=1 ;;
                -vv)  VERBOSE=2 ;;
                -vvv) VERBOSE=3 ;;
            esac
            shift
            ;;
        -*)
            echo "Error: Unknown option: $1" >&2
            usage >&2
            exit 1
            ;;
        *)
            TARGET_VERSION="$1"
            shift
            ;;
    esac
done

log_debug "Script started with target version: ${TARGET_VERSION:-auto}"

check_kubectl

log_info "Checking current kubectl context"
CURRENT_CONTEXT=$(kubectl config current-context 2>/dev/null)
log_verbose "Current context: $CURRENT_CONTEXT"

log_info "Checking for ArgoCD installation"
if ! kubectl get ns argocd &>/dev/null; then
    log_error "ArgoCD namespace not found. This script only upgrades existing installations."
    exit 1
fi
log_verbose "ArgoCD namespace found"

log_info "Checking current ArgoCD version"
CURRENT_VERSION=$(kubectl get deployment argocd-server -n argocd -o jsonpath='{.spec.template.spec.containers[0].image}' 2>/dev/null)
if [[ -n "$CURRENT_VERSION" ]]; then
    CURRENT_VERSION=$(echo "$CURRENT_VERSION" | sed 's/.*argocd:v\?//' | tr -d ' \n')
    if [[ -n "$CURRENT_VERSION" ]]; then
        CURRENT_VERSION="${CURRENT_VERSION#v}"
        log_verbose "Current ArgoCD version: $CURRENT_VERSION"
    else
        log_error "Could not extract ArgoCD version from image: $CURRENT_VERSION"
        exit 1
    fi
fi

if [[ -z "$TARGET_VERSION" ]]; then
    log_info "No target version specified, querying for latest version"
    log_verbose "Fetching latest release from GitHub"
    LATEST_VERSION=$(curl -s https://api.github.com/repos/argoproj/argo-cd/releases/latest | grep -oP '"tag_name":\s*"\K[^"]+' | sed 's/^v//')
    if [[ -n "$LATEST_VERSION" ]]; then
        log_verbose "Latest version available: $LATEST_VERSION"
        TARGET_VERSION="$LATEST_VERSION"
    else
        echo "Error: Could not fetch latest version" >&2
        exit 1
    fi
fi

log_info "Target version: $TARGET_VERSION"

log_debug "Determining update path from $CURRENT_VERSION to $TARGET_VERSION"

log_info "Applying ArgoCD manifests"
log_verbose "Downloading manifest from https://raw.githubusercontent.com/argoproj/argo-cd/v${TARGET_VERSION}/manifests/install.yaml"
curl -sLO "https://raw.githubusercontent.com/argoproj/argo-cd/v${TARGET_VERSION}/manifests/install.yaml"

log_debug "Applying manifest with kubectl"
if [[ "$DRY_RUN" == true ]]; then
    log_verbose "Dry-run mode: would apply manifest"
    kubectl apply -n argocd -f install.yaml --dry-run=client
else
    kubectl apply -n argocd -f install.yaml
fi

log_verbose "Cleaning up downloaded manifest"
rm -f install.yaml

log_info "Update to ArgoCD $TARGET_VERSION initiated"