package cluster

import (
	"context"
	"fmt"
	"os"
	"path/filepath"
	"sort"
	"strings"
	"sync"
	"time"
)

// reconcileNodeAccess runs one orchestration or CLI step.
// Signature: (o *Orchestrator) reconcileNodeAccess(ctx context.Context, nodes []string) error.
// Why: keeps behavior explicit so startup/shutdown workflows remain maintainable as services evolve.
func (o *Orchestrator) reconcileNodeAccess(ctx context.Context, nodes []string) error {
	if len(nodes) == 0 {
		return nil
	}
	parallelism := o.cfg.Shutdown.SSHParallelism
	if parallelism <= 0 {
		parallelism = 8
	}
	if parallelism > len(nodes) {
		parallelism = len(nodes)
	}
	sem := make(chan struct{}, parallelism)
	var wg sync.WaitGroup
	errCh := make(chan error, len(nodes))
	for _, node := range nodes {
		node := strings.TrimSpace(node)
		if node == "" || !o.sshManaged(node) {
			continue
		}
		wg.Add(1)
		go func() {
			defer wg.Done()
			sem <- struct{}{}
			defer func() { <-sem }()
			if _, err := o.ssh(ctx, node, "sudo -n /usr/bin/systemctl --version"); err != nil {
				errCh <- fmt.Errorf("%s: missing sudo access to /usr/bin/systemctl (--version): %w", node, err)
			}
		}()
	}
	wg.Wait()
	close(errCh)
	if len(errCh) == 0 {
		return nil
	}
	samples := []string{}
	for err := range errCh {
		samples = append(samples, err.Error())
		if len(samples) >= 4 {
			break
		}
	}
	return fmt.Errorf("access validation had %d errors (first: %s)", len(errCh), strings.Join(samples, " | "))
}

// waitForNodeSSHAuth runs one orchestration or CLI step.
// Signature: (o *Orchestrator) waitForNodeSSHAuth(ctx context.Context, nodes []string) error.
// Why: keeps behavior explicit so startup/shutdown workflows remain maintainable as services evolve.
func (o *Orchestrator) waitForNodeSSHAuth(ctx context.Context, nodes []string) error {
	if o.runner.DryRun || !o.cfg.Startup.RequireNodeSSHAuth {
		return nil
	}

	wait := time.Duration(o.cfg.Startup.NodeSSHAuthWaitSeconds) * time.Second
	if wait <= 0 {
		wait = 4 * time.Minute
	}
	poll := time.Duration(o.cfg.Startup.NodeSSHAuthPollSeconds) * time.Second
	if poll <= 0 {
		poll = 5 * time.Second
	}
	ignored := makeStringSet(o.cfg.Startup.IgnoreUnavailableNodes)
	seen := map[string]struct{}{}
	targets := make([]string, 0, len(nodes))
	for _, node := range nodes {
		node = strings.TrimSpace(node)
		if node == "" {
			continue
		}
		if _, skip := ignored[node]; skip {
			continue
		}
		if _, ok := seen[node]; ok {
			continue
		}
		seen[node] = struct{}{}
		targets = append(targets, node)
	}
	sort.Strings(targets)
	if len(targets) == 0 {
		return nil
	}

	deadline := time.Now().Add(wait)
	lastFailure := "unknown"
	lastLogged := time.Time{}
	for {
		authDenied := []string{}
		pending := []string{}
		for _, node := range targets {
			if !o.sshManaged(node) {
				authDenied = append(authDenied, fmt.Sprintf("%s(not in ssh_managed_nodes)", node))
				continue
			}
			out, err := o.sshWithTimeout(ctx, node, "echo __ANANKE_SSH_AUTH_OK__", 12*time.Second)
			if err != nil {
				detail := strings.TrimSpace(err.Error())
				full := strings.ToLower(strings.TrimSpace(detail + " " + out))
				switch {
				case strings.Contains(full, "permission denied"), strings.Contains(full, "publickey"), strings.Contains(full, "authentication"):
					authDenied = append(authDenied, fmt.Sprintf("%s(auth denied)", node))
				default:
					pending = append(pending, fmt.Sprintf("%s(unreachable)", node))
				}
				continue
			}
			if !strings.Contains(out, "__ANANKE_SSH_AUTH_OK__") {
				pending = append(pending, fmt.Sprintf("%s(unexpected output)", node))
			}
		}
		if len(authDenied) > 0 {
			sort.Strings(authDenied)
			return fmt.Errorf("ssh auth gate failed: %s", joinLimited(authDenied, 8))
		}
		if len(pending) == 0 {
			return nil
		}

		sort.Strings(pending)
		lastFailure = joinLimited(pending, 8)
		if time.Now().After(deadline) {
			return fmt.Errorf("node ssh auth gate did not pass within %s (%s)", wait, lastFailure)
		}
		if time.Since(lastLogged) >= 30*time.Second {
			remaining := time.Until(deadline).Round(time.Second)
			if remaining < 0 {
				remaining = 0
			}
			o.log.Printf("waiting for node ssh auth (%s remaining): %s", remaining, lastFailure)
			lastLogged = time.Now()
		}
		select {
		case <-ctx.Done():
			return ctx.Err()
		case <-time.After(poll):
		}
	}
}

// fluxSourceReady runs one orchestration or CLI step.
// Signature: (o *Orchestrator) fluxSourceReady(ctx context.Context) (bool, error).
// Why: keeps behavior explicit so startup/shutdown workflows remain maintainable as services evolve.
func (o *Orchestrator) fluxSourceReady(ctx context.Context) (bool, error) {
	out, err := o.kubectl(ctx, 10*time.Second, "-n", "flux-system", "get", "gitrepository", "flux-system", "-o", "jsonpath={.status.conditions[?(@.type==\"Ready\")].status}")
	if err != nil {
		return false, err
	}
	return strings.Contains(out, "True"), nil
}

// reportFluxSource runs one orchestration or CLI step.
// Signature: (o *Orchestrator) reportFluxSource(ctx context.Context, forceBranch string).
// Why: keeps behavior explicit so startup/shutdown workflows remain maintainable as services evolve.
func (o *Orchestrator) reportFluxSource(ctx context.Context, forceBranch string) {
	urlOut, urlErr := o.kubectl(ctx, 10*time.Second, "-n", "flux-system", "get", "gitrepository", "flux-system", "-o", "jsonpath={.spec.url}")
	if urlErr == nil {
		currentURL := strings.TrimSpace(urlOut)
		o.log.Printf("flux-source-url=%s", currentURL)
		expectedURL := strings.TrimSpace(o.cfg.ExpectedFluxSource)
		if expectedURL != "" && normalizeGitURL(currentURL) != normalizeGitURL(expectedURL) {
			o.log.Printf("warning: flux source URL is %q, expected %q", currentURL, expectedURL)
		}
	}
	branchOut, branchErr := o.kubectl(ctx, 10*time.Second, "-n", "flux-system", "get", "gitrepository", "flux-system", "-o", "jsonpath={.spec.ref.branch}")
	if branchErr == nil {
		branch := strings.TrimSpace(branchOut)
		o.log.Printf("flux-source-branch=%s", branch)
		if forceBranch == "" && branch != o.cfg.ExpectedFluxBranch {
			o.log.Printf("warning: flux source branch is '%s', expected '%s'", branch, o.cfg.ExpectedFluxBranch)
		}
	}
}

// guardFluxSourceDrift runs one orchestration or CLI step.
// Signature: (o *Orchestrator) guardFluxSourceDrift(ctx context.Context, expectedBranch string, allowBranchPatch bool) error.
// Why: keeps behavior explicit so startup/shutdown workflows remain maintainable as services evolve.
func (o *Orchestrator) guardFluxSourceDrift(ctx context.Context, expectedBranch string, allowBranchPatch bool) error {
	urlOut, err := o.kubectl(
		ctx,
		10*time.Second,
		"-n", "flux-system",
		"get", "gitrepository", "flux-system",
		"-o", "jsonpath={.spec.url}",
	)
	if err != nil {
		if isNotFoundErr(err) {
			o.log.Printf("warning: flux gitrepository/flux-system not found while checking source drift")
			return nil
		}
		return fmt.Errorf("read flux source url: %w", err)
	}
	currentURL := strings.TrimSpace(urlOut)
	expectedURL := strings.TrimSpace(o.cfg.ExpectedFluxSource)
	if expectedURL != "" && normalizeGitURL(currentURL) != normalizeGitURL(expectedURL) {
		return fmt.Errorf("startup blocked: flux source url drift detected (current=%q expected=%q)", currentURL, expectedURL)
	}

	branchOut, err := o.kubectl(
		ctx,
		10*time.Second,
		"-n", "flux-system",
		"get", "gitrepository", "flux-system",
		"-o", "jsonpath={.spec.ref.branch}",
	)
	if err != nil {
		return fmt.Errorf("read flux source branch: %w", err)
	}
	currentBranch := strings.TrimSpace(branchOut)
	if expectedBranch == "" || currentBranch == expectedBranch || allowBranchPatch {
		return nil
	}
	return fmt.Errorf("startup blocked: flux source branch drift detected (current=%q expected=%q)", currentBranch, expectedBranch)
}

// ensureFluxBranch runs one orchestration or CLI step.
// Signature: (o *Orchestrator) ensureFluxBranch(ctx context.Context, branch string, allowPatch bool) error.
// Why: keeps behavior explicit so startup/shutdown workflows remain maintainable as services evolve.
func (o *Orchestrator) ensureFluxBranch(ctx context.Context, branch string, allowPatch bool) error {
	branch = strings.TrimSpace(branch)
	if branch == "" {
		return nil
	}

	out, err := o.kubectl(
		ctx,
		10*time.Second,
		"-n", "flux-system",
		"get", "gitrepository", "flux-system",
		"-o", "jsonpath={.spec.ref.branch}",
	)
	if err != nil {
		if isNotFoundErr(err) {
			o.log.Printf("warning: flux gitrepository/flux-system not found while ensuring branch=%s", branch)
			return nil
		}
		return fmt.Errorf("read flux source branch: %w", err)
	}
	current := strings.TrimSpace(out)
	if current == branch {
		return nil
	}
	if !allowPatch {
		return fmt.Errorf("startup blocked: flux source branch is %q but expected %q (use --force-flux-branch to patch intentionally)", current, branch)
	}
	patch := fmt.Sprintf(`{"spec":{"ref":{"branch":"%s"}}}`, branch)
	if _, err := o.kubectl(
		ctx,
		20*time.Second,
		"-n", "flux-system",
		"patch", "gitrepository", "flux-system",
		"--type=merge",
		"-p", patch,
	); err != nil {
		return fmt.Errorf("set flux source branch %q (current %q): %w", branch, current, err)
	}
	o.log.Printf("updated flux source branch from %q to %q", current, branch)
	return nil
}

// normalizeGitURL runs one orchestration or CLI step.
// Signature: normalizeGitURL(raw string) string.
// Why: keeps behavior explicit so startup/shutdown workflows remain maintainable as services evolve.
func normalizeGitURL(raw string) string {
	raw = strings.TrimSpace(strings.ToLower(raw))
	raw = strings.TrimSuffix(raw, "/")
	raw = strings.TrimSuffix(raw, ".git")
	return raw
}

// bootstrapLocal runs one orchestration or CLI step.
// Signature: (o *Orchestrator) bootstrapLocal(ctx context.Context) error.
// Why: keeps behavior explicit so startup/shutdown workflows remain maintainable as services evolve.
func (o *Orchestrator) bootstrapLocal(ctx context.Context) error {
	failures := 0
	successes := 0
	for _, rel := range o.cfg.LocalBootstrapPaths {
		full := filepath.Join(o.cfg.IACRepoPath, rel)
		o.log.Printf("local bootstrap apply rel=%s path=%s", rel, full)
		if o.runner.DryRun {
			successes++
			continue
		}
		if _, err := o.kubectl(ctx, 2*time.Minute, "apply", "-k", full); err != nil {
			o.log.Printf("warning: local bootstrap apply failed at %s: %v", full, err)
			o.log.Printf("local bootstrap fallback render/apply with LoadRestrictionsNone for %s", full)
			if fallbackErr := o.applyKustomizeFallback(ctx, full); fallbackErr != nil {
				o.log.Printf("warning: local bootstrap fallback failed at %s: %v", full, fallbackErr)
				o.log.Printf("local bootstrap cache apply for rel=%s", rel)
				if cacheErr := o.applyBootstrapCache(ctx, rel); cacheErr != nil {
					failures++
					o.log.Printf("warning: local bootstrap cache apply failed for rel=%s: %v", rel, cacheErr)
					continue
				}
			}
		}
		successes++
	}
	if failures > 0 && successes == 0 {
		return fmt.Errorf("local bootstrap apply failed for every configured path (%d total)", failures)
	}
	return nil
}

// applyKustomizeFallback runs one orchestration or CLI step.
// Signature: (o *Orchestrator) applyKustomizeFallback(ctx context.Context, full string) error.
// Why: keeps behavior explicit so startup/shutdown workflows remain maintainable as services evolve.
func (o *Orchestrator) applyKustomizeFallback(ctx context.Context, full string) error {
	cmd := fmt.Sprintf("kubectl kustomize --load-restrictor=LoadRestrictionsNone %q | kubectl apply -f -", full)
	if _, err := o.runSensitive(ctx, 3*time.Minute, "sh", "-lc", cmd); err != nil {
		return err
	}
	return nil
}

// syncLocalIACRepo runs one orchestration or CLI step.
// Signature: (o *Orchestrator) syncLocalIACRepo(ctx context.Context) error.
// Why: keeps behavior explicit so startup/shutdown workflows remain maintainable as services evolve.
func (o *Orchestrator) syncLocalIACRepo(ctx context.Context) error {
	repo := strings.TrimSpace(o.cfg.IACRepoPath)
	if repo == "" {
		return fmt.Errorf("iac repo path is empty")
	}
	gitDir := filepath.Join(repo, ".git")
	if stat, err := os.Stat(gitDir); err != nil || !stat.IsDir() {
		return fmt.Errorf("iac repo %s is not a git checkout", repo)
	}
	statusOut, statusErr := o.runSensitive(ctx, 10*time.Second, "git", "-C", repo, "status", "--porcelain")
	if statusErr != nil {
		return fmt.Errorf("inspect iac repo working tree: %w", statusErr)
	}
	if strings.TrimSpace(statusOut) != "" {
		o.log.Printf("warning: skipping local titan-iac sync because working tree is dirty")
		return nil
	}
	branch := strings.TrimSpace(o.cfg.ExpectedFluxBranch)
	if branch == "" {
		branch = "main"
	}
	if _, err := o.runSensitive(ctx, 45*time.Second, "git", "-C", repo, "fetch", "origin", "--prune"); err != nil {
		return fmt.Errorf("git fetch origin: %w", err)
	}
	if _, err := o.runSensitive(ctx, 20*time.Second, "git", "-C", repo, "checkout", branch); err != nil {
		return fmt.Errorf("git checkout %s: %w", branch, err)
	}
	if _, err := o.runSensitive(ctx, 20*time.Second, "git", "-C", repo, "reset", "--hard", "origin/"+branch); err != nil {
		return fmt.Errorf("git reset --hard origin/%s: %w", branch, err)
	}
	return nil
}

// refreshBootstrapCache runs one orchestration or CLI step.
// Signature: (o *Orchestrator) refreshBootstrapCache(ctx context.Context) error.
// Why: keeps behavior explicit so startup/shutdown workflows remain maintainable as services evolve.
func (o *Orchestrator) refreshBootstrapCache(ctx context.Context) error {
	if len(o.cfg.LocalBootstrapPaths) == 0 {
		return nil
	}
	if err := os.MkdirAll(o.bootstrapCacheDir(), 0o755); err != nil {
		return fmt.Errorf("ensure bootstrap cache dir: %w", err)
	}
	rendered := 0
	for _, rel := range o.cfg.LocalBootstrapPaths {
		rel = strings.TrimSpace(rel)
		if rel == "" {
			continue
		}
		full := filepath.Join(o.cfg.IACRepoPath, rel)
		if stat, err := os.Stat(full); err != nil || !stat.IsDir() {
			o.log.Printf("warning: skip bootstrap cache render for rel=%s (path missing)", rel)
			continue
		}
		cmd := fmt.Sprintf("kubectl kustomize --load-restrictor=LoadRestrictionsNone %q", full)
		manifest, err := o.runSensitive(ctx, 2*time.Minute, "sh", "-lc", cmd)
		if err != nil {
			o.log.Printf("warning: bootstrap cache render failed for rel=%s: %v", rel, err)
			continue
		}
		cachePath := o.bootstrapCachePath(rel)
		if err := os.WriteFile(cachePath, []byte(manifest+"\n"), 0o644); err != nil {
			o.log.Printf("warning: bootstrap cache write failed for rel=%s path=%s: %v", rel, cachePath, err)
			continue
		}
		rendered++
	}
	if rendered == 0 {
		return fmt.Errorf("no bootstrap cache manifests rendered")
	}
	o.log.Printf("bootstrap cache refreshed (%d paths)", rendered)
	return nil
}

// applyBootstrapCache runs one orchestration or CLI step.
// Signature: (o *Orchestrator) applyBootstrapCache(ctx context.Context, rel string) error.
// Why: keeps behavior explicit so startup/shutdown workflows remain maintainable as services evolve.
func (o *Orchestrator) applyBootstrapCache(ctx context.Context, rel string) error {
	cachePath := o.bootstrapCachePath(rel)
	if _, err := os.Stat(cachePath); err != nil {
		return fmt.Errorf("bootstrap cache missing at %s: %w", cachePath, err)
	}
	if _, err := o.kubectl(ctx, 2*time.Minute, "apply", "-f", cachePath); err != nil {
		return err
	}
	return nil
}

// bootstrapCacheDir runs one orchestration or CLI step.
// Signature: (o *Orchestrator) bootstrapCacheDir() string.
// Why: keeps behavior explicit so startup/shutdown workflows remain maintainable as services evolve.
func (o *Orchestrator) bootstrapCacheDir() string {
	return filepath.Join(o.cfg.State.Dir, "bootstrap-cache")
}

// bootstrapCachePath runs one orchestration or CLI step.
// Signature: (o *Orchestrator) bootstrapCachePath(rel string) string.
// Why: keeps behavior explicit so startup/shutdown workflows remain maintainable as services evolve.
func (o *Orchestrator) bootstrapCachePath(rel string) string {
	safe := strings.TrimSpace(rel)
	safe = strings.ReplaceAll(safe, "/", "__")
	safe = strings.ReplaceAll(safe, string(os.PathSeparator), "__")
	return filepath.Join(o.bootstrapCacheDir(), safe+".yaml")
}

// waitForFluxSourceReady runs one orchestration or CLI step.
// Signature: (o *Orchestrator) waitForFluxSourceReady(ctx context.Context, window time.Duration) (bool, error).
// Why: keeps behavior explicit so startup/shutdown workflows remain maintainable as services evolve.
func (o *Orchestrator) waitForFluxSourceReady(ctx context.Context, window time.Duration) (bool, error) {
	if o.runner.DryRun {
		return true, nil
	}
	deadline := time.Now().Add(window)
	for {
		ready, err := o.fluxSourceReady(ctx)
		if err != nil {
			return false, err
		}
		if ready {
			return true, nil
		}
		if time.Now().After(deadline) {
			return false, nil
		}
		select {
		case <-ctx.Done():
			return false, ctx.Err()
		case <-time.After(5 * time.Second):
		}
	}
}