#!/usr/bin/env nu
# Start local provisioning services via Docker Compose
# Usage: nu provisioning/scripts/start-local.nu [--stop|--restart|--logs|--status]
#
# Options:
#   --stop      Stop all services
#   --restart   Restart all services
#   --logs      Follow logs in real-time
#   --status    Show service status
#   (default)   Start services and show info

use std log

def result_ok [value: any] { {ok: $value, err: null} }
def result_err [message: string] { {ok: null, err: $message} }

def is_ok [result: record] { $result.err == null }

# Phase 1: Validate environment and preconditions
def validate_environment [] {
    # Guard 1: Docker is installed
    let docker_check = (
        try { which docker | length > 0 } catch { false }
    )
    if not $docker_check {
        return (result_err "Docker not found. Please install Docker Desktop or Docker Engine.")
    }

    # Guard 2: Docker daemon is running
    let docker_running = (
        try { docker ps out> /dev/null 2>&1; true } catch { false }
    )
    if not $docker_running {
        return (result_err "Docker daemon is not running. Please start Docker and try again.")
    }

    # Guard 3: docker-compose.local.yml exists
    let compose_file = "provisioning/docker-compose.local.yml"
    if not ($compose_file | path exists) {
        return (result_err $"Docker Compose file not found: ($compose_file)")
    }

    # Guard 4: .env.local exists (or create from template)
    let env_file = ".env.local"
    let env_template = "provisioning/.env.local.template"
    if not ($env_file | path exists) {
        if ($env_template | path exists) {
            log info $"Creating ($env_file) from template"
            cp $env_template $env_file
        } else {
            log warning $"(.env.local) not found, using defaults"
        }
    }

    result_ok null
}

# Phase 2: Check port availability
def check_ports [] {
    let ports = [
        {port: 8080, service: "API Gateway"}
        {port: 8082, service: "Extension Registry"}
        {port: 9090, service: "Orchestrator"}
        {port: 2379, service: "ETCD Client"}
        {port: 2380, service: "ETCD Peer"}
        {port: 9091, service: "Prometheus"}
    ]

    let unavailable = $ports | where {|p|
        try {
            let result = (ss -tuln 2>/dev/null | grep $"(:($p.port) )")
            $result | length > 0
        } catch {
            false
        }
    }

    if ($unavailable | length) > 0 {
        let port_list = ($unavailable | map { |p| $"  - Port ($p.port): ($p.service)" } | str join "\n")
        return (result_err $"The following ports are already in use:\n($port_list)\n\nEither stop the conflicting services or wait for cleanup.")
    }

    result_ok null
}

# Phase 3: Start Docker Compose services
def start_services [] {
    log info "Starting Docker Compose services..."

    try {
        docker compose -f provisioning/docker-compose.local.yml --env-file .env.local up -d
        result_ok null
    } catch {|err|
        result_err $"Failed to start services: ($err.msg)"
    }
}

# Phase 4: Wait for health checks
def wait_for_services [timeout_secs: int] {
    log info $"Waiting for services to be healthy (timeout: ($timeout_secs)s)..."

    let services = [
        {name: "etcd", port: 2379}
        {name: "extension-registry", port: 8082}
        {name: "orchestrator", port: 9090}
        {name: "api-gateway", port: 8080}
    ]

    let start_time = (date now | into int)
    mut all_healthy = false

    loop {
        let elapsed = ((date now | into int) - $start_time)

        if $elapsed > $timeout_secs {
            return (result_err "Services did not become healthy within timeout period. Check docker logs.")
        }

        let health_results = $services | map {|s|
            let healthy = (
                try {
                    curl -s -f -m 2 $"http://localhost:($s.port)/api/v1/health" out> /dev/null 2>&1
                    true
                } catch {
                    false
                }
            )
            {service: $s.name, healthy: $healthy}
        }

        let healthy_count = ($health_results | where healthy | length)

        if $healthy_count == ($services | length) {
            log info "All services are healthy"
            $all_healthy = true
            break
        }

        let unhealthy = $health_results | where {|h| not $h.healthy} | map {|h| $h.service}
        log debug $"Waiting for services: ($unhealthy | str join ', ')"

        sleep 2sec
    }

    result_ok $all_healthy
}

# Phase 5: Verify service endpoints
def verify_endpoints [] {
    log info "Verifying service endpoints..."

    let endpoints = [
        {name: "API Gateway", url: "http://localhost:8080/api/v1/health"}
        {name: "Extension Registry", url: "http://localhost:8082/api/v1/health"}
        {name: "Orchestrator", url: "http://localhost:9090/api/v1/health"}
        {name: "ETCD", url: "http://localhost:2379/version"}
    ]

    let results = $endpoints | map {|ep|
        let response = (
            try {
                curl -s $ep.url | from json
            } catch {
                null
            }
        )
        {service: $ep.name, accessible: ($response != null)}
    }

    let all_accessible = ($results | where accessible | length) == ($results | length)

    if not $all_accessible {
        let inaccessible = ($results | where {|r| not $r.accessible} | map {|r| $r.service})
        log warning $"Some endpoints are not accessible: ($inaccessible | str join ', ')"
    } else {
        log info "All endpoints are accessible"
    }

    result_ok $results
}

# Phase 6: Display access information
def show_info [] {
    log info ""
    log info "=========================================="
    log info "Provisioning Local Services Started"
    log info "=========================================="
    log info ""
    log info "Service URLs:"
    log info "  API Gateway:         http://localhost:8080"
    log info "  Extension Registry:  http://localhost:8082"
    log info "  Orchestrator:        http://localhost:9090"
    log info "  ETCD Client:         http://localhost:2379"
    log info "  Prometheus:          http://localhost:9091"
    log info ""
    log info "Useful commands:"
    log info "  View logs:           docker compose -f provisioning/docker-compose.local.yml logs -f"
    log info "  Stop services:       docker compose -f provisioning/docker-compose.local.yml down"
    log info "  Container status:    docker ps --filter label=com.docker.compose.project=provisioning"
    log info ""
    log info "Test connectivity:"
    log info "  curl http://localhost:8082/api/v1/health"
    log info "  curl http://localhost:9090/api/v1/health"
    log info ""
    log info "=========================================="
}

# Command: Stop services
def stop_services [] {
    log info "Stopping Docker Compose services..."

    try {
        docker compose -f provisioning/docker-compose.local.yml --env-file .env.local down
        log info "Services stopped successfully"
        result_ok null
    } catch {|err|
        result_err $"Failed to stop services: ($err.msg)"
    }
}

# Command: Restart services
def restart_services [] {
    let stop_result = stop_services
    if not (is_ok $stop_result) {
        return $stop_result
    }

    sleep 2sec

    let start_result = start_services
    if not (is_ok $start_result) {
        return $start_result
    }

    wait_for_services 60
}

# Command: Show logs
def show_logs [] {
    log info "Following Docker Compose logs (Ctrl+C to stop)..."
    docker compose -f provisioning/docker-compose.local.yml --env-file .env.local logs -f
}

# Command: Show status
def show_status [] {
    log info "Checking service status..."
    docker compose -f provisioning/docker-compose.local.yml ps
}

# Main execution
def main [--stop: bool, --restart: bool, --logs: bool, --status: bool] {
    # Load environment
    if (".env.local" | path exists) {
        load-env (.env.local | open --raw | lines | where {|l| $l !~ '^#' and $l | str trim | length > 0} | each {|l|
            let parts = ($l | split column '=' -c 2)
            {key: ($parts.0.0 | str trim), value: ($parts.0.1 | str trim)}
        } | each {|kv|
            {($kv.key): $kv.value}
        } | reduce item=null as $item ({}; . + $item))
    }

    # Route to appropriate command
    if $stop {
        let result = (stop_services)
        if not (is_ok $result) {
            log error $result.err
            exit 1
        }
    } else if $restart {
        let result = (restart_services)
        if not (is_ok $result) {
            log error $result.err
            exit 1
        }
        show_info
    } else if $logs {
        show_logs
    } else if $status {
        show_status
    } else {
        # Default: Start services
        let validate = (validate_environment)
        if not (is_ok $validate) {
            log error $validate.err
            exit 1
        }

        let ports = (check_ports)
        if not (is_ok $ports) {
            log error $ports.err
            exit 1
        }

        let start = (start_services)
        if not (is_ok $start) {
            log error $start.err
            exit 1
        }

        let wait = (wait_for_services 60)
        if not (is_ok $wait) {
            log error $wait.err
            exit 1
        }

        let verify = (verify_endpoints)
        if not (is_ok $verify) {
            log error $verify.err
            exit 1
        }

        show_info
    }
}

main ...$nu.args