//go:build linux

package dashboard

import (
	"context"
	"errors"
	"fmt"

	"github.com/nezhahq/nezha/integration/agentcompat/internal/client"
	processharness "github.com/nezhahq/nezha/integration/agentcompat/internal/process"
)

func (dashboard *Dashboard) StopProcess(ctx context.Context) (RuntimeIdentity, error) {
	dashboard.lifecycleMu.Lock()
	defer dashboard.lifecycleMu.Unlock()
	dashboard.stateMu.Lock()
	process := dashboard.currentProcess
	dashboard.currentProcess = nil
	dashboard.supervisor = nil
	dashboard.stateMu.Unlock()
	if process == nil {
		return RuntimeIdentity{}, errors.New("dashboard process is not running")
	}
	if process.receiptConn != nil {
		_ = process.receiptConn.Close()
	}
	if process.httpTransport != nil {
		process.httpTransport.CloseIdleConnections()
	}
	if process.tlsTransport != nil {
		process.tlsTransport.CloseIdleConnections()
	}
	if err := process.supervisor.Stop(ctx); err != nil {
		return process.identity, fmt.Errorf("stop dashboard process: %w", err)
	}
	process.record = process.supervisor.CleanupRecord()
	return process.identity, nil
}

func (dashboard *Dashboard) StartProcess(ctx context.Context) (RuntimeIdentity, error) {
	dashboard.lifecycleMu.Lock()
	defer dashboard.lifecycleMu.Unlock()
	dashboard.stateMu.Lock()
	if dashboard.currentProcess != nil {
		dashboard.stateMu.Unlock()
		return RuntimeIdentity{}, errors.New("dashboard process is already running")
	}
	dashboard.generation++
	generation := dashboard.generation
	dashboard.stateMu.Unlock()
	dashboard.receiptMu.Lock()
	dashboard.receiptAccepted = false
	dashboard.receiptAcceptedCount = 0
	dashboard.receiptGeneration = 0
	dashboard.receiptMu.Unlock()
	process, err := dashboard.startGeneration(ctx, generation)
	if err != nil {
		return RuntimeIdentity{}, err
	}
	dashboard.stateMu.Lock()
	dashboard.currentProcess = process
	dashboard.supervisor = process.supervisor
	dashboard.processes = append(dashboard.processes, process)
	dashboard.stateMu.Unlock()
	return process.identity, nil
}

func (dashboard *Dashboard) FixtureIdentity() FixtureIdentity {
	identity := FixtureIdentity{WorkspaceRoot: dashboard.workspace.Root(), ConfigPath: dashboard.configPath, DatabasePath: dashboard.databasePath, BinaryPath: dashboard.binaryPath}
	if dashboard.httpListener != nil {
		identity.HTTP = dashboard.httpListener.Identity()
	}
	if dashboard.receiptListener != nil {
		identity.Receipt = dashboard.receiptListener.Identity()
	}
	if dashboard.httpsListener != nil {
		identity.HTTPS = dashboard.httpsListener.Identity()
	}
	return identity
}

func (dashboard *Dashboard) RuntimeIdentity() RuntimeIdentity {
	dashboard.stateMu.Lock()
	defer dashboard.stateMu.Unlock()
	if dashboard.currentProcess == nil {
		return RuntimeIdentity{}
	}
	return dashboard.currentProcess.identity
}

func (dashboard *Dashboard) Restart(ctx context.Context) error {
	if _, err := dashboard.StopProcess(ctx); err != nil {
		return err
	}
	_, err := dashboard.StartProcess(ctx)
	return err
}

func (dashboard *Dashboard) cleanupOnCancellation(ctx context.Context) {
	select {
	case <-ctx.Done():
		dashboard.cleanupOnce.Do(func() { go dashboard.cleanup(context.WithoutCancel(ctx)) })
	case <-dashboard.cleanupDone:
	}
}

func (dashboard *Dashboard) cleanup(ctx context.Context) {
	defer close(dashboard.cleanupDone)
	var stopError error
	cleanupReceipt := dashboard.cleanupProcesses(ctx, &stopError)
	if err := dashboard.workspace.Close(); err != nil {
		stopError = errors.Join(stopError, fmt.Errorf("close dashboard workspace: %w", err))
		cleanupReceipt = processharness.NewCleanupReceipt(append(cleanupReceipt.Processes, processharness.CleanupRecord{Name: "dashboard-workspace", Error: client.Redact(err.Error())}))
	}
	dashboard.cleanupMu.Lock()
	dashboard.cleanupError = stopError
	dashboard.cleanupReceipt = cleanupReceipt
	dashboard.cleanupMu.Unlock()
}

func (dashboard *Dashboard) cleanupProcesses(ctx context.Context, stopError *error) processharness.CleanupReceipt {
	cleanupReceipt := processharness.CleanupReceipt{}
	dashboard.stateMu.Lock()
	processes := append([]*dashboardGeneration(nil), dashboard.processes...)
	legacySupervisor := dashboard.supervisor
	dashboard.stateMu.Unlock()
	if len(processes) == 0 && legacySupervisor != nil {
		if err := legacySupervisor.Stop(ctx); err != nil {
			*stopError = errors.Join(*stopError, fmt.Errorf("stop dashboard process: %w", err))
		}
		return processharness.NewCleanupReceipt([]processharness.CleanupRecord{legacySupervisor.CleanupRecord()})
	}
	for _, process := range processes {
		if process.receiptConn != nil {
			_ = process.receiptConn.Close()
		}
		if process.httpTransport != nil {
			process.httpTransport.CloseIdleConnections()
		}
		if process.tlsTransport != nil {
			process.tlsTransport.CloseIdleConnections()
		}
		stopContext, cancel := context.WithTimeout(ctx, failedStartCleanupTimeout)
		if err := process.supervisor.Stop(stopContext); err != nil {
			*stopError = errors.Join(*stopError, fmt.Errorf("stop dashboard process: %w", err))
		}
		cancel()
		process.record = process.supervisor.CleanupRecord()
		if process.record.Forced {
			*stopError = errors.Join(*stopError, errors.New("dashboard required forced SIGKILL cleanup"))
		}
		cleanupReceipt.Processes = append(cleanupReceipt.Processes, process.record)
	}
	return processharness.NewCleanupReceipt(cleanupReceipt.Processes)
}