package api

import (
	"fmt"
	"net/http"
	"strings"

	"github.com/rcourtman/pulse-go-rewrite/internal/api/agenttokens"
	"github.com/rcourtman/pulse-go-rewrite/internal/api/configapi"
	"github.com/rcourtman/pulse-go-rewrite/internal/config"
)

const (
	proxmoxInstallTypePVE = "pve"
	proxmoxInstallTypePBS = "pbs"
	// agentInstallTypeHost marks install tokens minted for the generic unified
	// host agent flow (Settings > Infrastructure > Add Pulse Agent), as opposed
	// to the Proxmox-specific pve/pbs installer.
	agentInstallTypeHost = "host"
)

var (
	errAgentInstallTokenGeneration = agenttokens.ErrGeneration
	errAgentInstallTokenRecord     = agenttokens.ErrRecord
	errAgentInstallTokenPersist    = agenttokens.ErrPersist
)

func normalizeProxmoxInstallType(raw string) (string, error) {
	installType := strings.ToLower(strings.TrimSpace(raw))
	if installType != proxmoxInstallTypePVE && installType != proxmoxInstallTypePBS {
		return "", fmt.Errorf("Type must be 'pve' or 'pbs'")
	}
	return installType, nil
}

func proxmoxAgentInstallScopes(enableCommands bool) []string {
	return agenttokens.ProxmoxScopes(enableCommands)
}

// hostAgentInstallScopes returns the scopes for a generic unified host agent
// install token. The exec scope is included only when the operator asked for
// command execution, because the token is minted before the agent enrols and
// scopes cannot be upgraded on an existing token.
func hostAgentInstallScopes(enableCommands bool) []string {
	return agenttokens.HostScopes(enableCommands)
}

type issueAgentInstallTokenOptions = agenttokens.IssueOptions

func issueAndPersistAgentInstallToken(cfg *config.Config, persistence *config.ConfigPersistence, opts issueAgentInstallTokenOptions) (string, *config.APITokenRecord, error) {
	return agenttokens.IssueAndPersist(cfg, persistence, opts)
}

type agentInstallCommandOptions = configapi.AgentInstallCommandOptions

type setupScriptInstallArtifact = configapi.SetupScriptInstallArtifact

func normalizeAgentInstallBaseURL(raw string) string {
	return strings.TrimRight(strings.TrimSpace(raw), "/")
}

func posixShellQuote(value string) string {
	escaped := strings.ReplaceAll(value, "'", `'"'"'`)
	return "'" + escaped + "'"
}

func installBaseURLRequiresInsecure(raw string) bool {
	baseURL := strings.ToLower(strings.TrimSpace(raw))
	return strings.HasPrefix(baseURL, "http://")
}

func authConfiguredForAgentLifecycle(cfg *config.Config) bool {
	if cfg == nil {
		return false
	}

	return (strings.TrimSpace(cfg.AuthUser) != "" && strings.TrimSpace(cfg.AuthPass) != "") ||
		cfg.HasAPITokens() ||
		strings.TrimSpace(cfg.ProxyAuthSecret) != "" ||
		hasEnabledSSOProvidersForAuth(cfg)
}

func withPrivilegeEscalation(command string) string {
	const installPipe = "| bash -s --"

	idx := strings.Index(command, installPipe)
	if idx == -1 {
		return command
	}

	args := command[idx+len(installPipe):]
	return command[:idx] +
		`| { if [ "$(id -u)" -eq 0 ]; then bash -s --` + args +
		`; elif command -v sudo >/dev/null 2>&1; then sudo bash -s --` + args +
		`; else echo "Root privileges required. Run as root (su -) and retry." >&2; exit 1; fi; }`
}

func buildProxmoxAgentInstallCommand(opts agentInstallCommandOptions) string {
	return configapi.BuildProxmoxAgentInstallCommand(opts)
}

func containerRuntimeAgentScopes(enableHost bool) []string {
	scopes := []string{config.ScopeDockerReport}
	if enableHost {
		scopes = append(scopes,
			config.ScopeAgentReport,
			config.ScopeAgentConfigRead,
		)
	}
	return scopes
}

func containerRuntimeAgentHostFlag(enableHost bool) string {
	if enableHost {
		return "--enable-host"
	}
	return "--enable-host=false"
}

func buildContainerRuntimeAgentInstallCommand(baseURL string, token string, enableHost bool) string {
	return configapi.BuildContainerRuntimeAgentInstallCommand(baseURL, token, enableHost)
}

// The diagnostic reference must not compete with the installer's complete
// service renderer or expose the issued token. Its default Linux state path
// matches scripts/install.sh; custom/least-privilege profiles keep their
// installer-generated unit instead of replacing it with this reference.
func buildContainerRuntimeAgentServiceSnippet(baseURL string, enableHost bool) (string, error) {
	baseURL = normalizeAgentInstallBaseURL(baseURL)
	// Environment= does not expand shell variables, but systemd does expand %
	// specifiers. Escape those as well as the unit's quoting/control boundary.
	urlLine, err := quoteSystemdEnvironment("PULSE_URL", strings.ReplaceAll(baseURL, "%", "%%"))
	if err != nil {
		return "", err
	}
	trustArgs := ""
	if installBaseURLRequiresInsecure(baseURL) {
		trustArgs = " --insecure"
	}
	return fmt.Sprintf("# Default Linux reference only. Run installCommand to create the private token file and complete service.\n# Keep the installer-generated unit for custom state directories or privilege profiles.\n[Service]\nType=simple\n%s\nExecStart=/usr/local/bin/pulse-agent --url ${PULSE_URL} --token-file /var/lib/pulse-agent/token --enable-docker %s --interval 30s%s\nRestart=always\nRestartSec=5s\nUser=root", urlLine, containerRuntimeAgentHostFlag(enableHost), trustArgs), nil
}

func buildSetupScriptCommand(scriptURL string, token string) string {
	return configapi.BuildSetupScriptCommand(scriptURL, token)
}

func buildSetupScriptTokenHint(token string) string {
	trimmed := strings.TrimSpace(token)
	if len(trimmed) <= 6 {
		return trimmed
	}
	return fmt.Sprintf("%s…%s", trimmed[:3], trimmed[len(trimmed)-3:])
}

func buildSetupScriptURL(baseURL string, installType string, host string, pulseURL string, backupPerms bool) string {
	return configapi.BuildSetupScriptURL(baseURL, installType, host, pulseURL, backupPerms)
}

func buildSetupScriptDownloadURL(baseURL string, installType string, host string, pulseURL string, backupPerms bool, setupToken string) string {
	return configapi.BuildSetupScriptDownloadURL(baseURL, installType, host, pulseURL, backupPerms, setupToken)
}

func buildSetupScriptFileName(installType string) string {
	return fmt.Sprintf("pulse-setup-%s.sh", strings.TrimSpace(installType))
}

func buildSetupScriptInstallArtifact(baseURL string, installType string, host string, pulseURL string, backupPerms bool, setupToken string, expiresAt int64) setupScriptInstallArtifact {
	return configapi.BuildSetupScriptInstallArtifact(baseURL, installType, host, pulseURL, backupPerms, setupToken, expiresAt)
}

func resolveConfigAgentInstallBaseURL(req *http.Request, cfg *config.Config, hostedMode bool) string {
	return resolveConfiguredPublicBaseURL(req, cfg, hostedMode)
}

func writeConfigAgentInstallBaseURLUnavailable(w http.ResponseWriter) {
	http.Error(w, "A valid external Pulse URL is required", http.StatusServiceUnavailable)
}