package main

import (
	"context"
	"errors"
	"fmt"
	"io"
	"os"
	"os/signal"
	"path/filepath"
	"strings"
	"syscall"

	"gitea.maximumdirect.net/eric/ReleaseKit"
	"gitea.maximumdirect.net/eric/ReleaseKit/buildinfo"
	"gitea.maximumdirect.net/eric/ReleaseKit/cmd/releasekit/internal/cli"
	"gitea.maximumdirect.net/eric/ReleaseKit/internal/artifact"
	"gitea.maximumdirect.net/eric/ReleaseKit/internal/git"
	"gitea.maximumdirect.net/eric/ReleaseKit/internal/releaseidentity"
)

func main() {
	ctx, stop := signal.NotifyContext(context.Background(), os.Interrupt, syscall.SIGTERM)
	code := run(ctx, os.Args[1:], os.Stdout, os.Stderr)
	stop()
	os.Exit(code)
}

func run(ctx context.Context, args []string, stdout, stderr io.Writer) int {
	invocation, err := cli.Parse(args)
	if err != nil {
		fmt.Fprintf(stderr, "%v\n%s\n", err, cli.Usage)
		return 2
	}
	if invocation.Command != cli.VersionCommand {
		invocation.Repository, err = git.RepositoryRoot(ctx, invocation.Repository)
		if err != nil {
			fmt.Fprintf(stderr, "%v\n", err)
			return 1
		}
	}

	switch invocation.Command {
	case cli.VersionCommand:
		fmt.Fprintf(stdout, "releasekit %s\n", buildinfo.Version())
		return 0
	case cli.CheckAction, cli.PublishAction:
		settings, err := cli.LoadSettings(invocation.Repository, invocation.ConfigPath)
		if err != nil {
			fmt.Fprintf(stderr, "load profile: %v\n", err)
			return 2
		}
		request := candidateRequest(invocation, settings, stderr)
		if invocation.Command == cli.PublishAction {
			if err := checkExpectedModule(invocation.Repository, invocation.ExpectedModule, settings.ModuleDir); err != nil {
				fmt.Fprintf(stderr, "profile module selection: %v\n", err)
				return 2
			}
			request.ExpectedPushURL = settings.ExpectedPushURL
			fmt.Fprintf(stderr, "validating and publishing module %s version %s\n", selectedModuleLabel(settings.ModuleDir), invocation.Version)
			result, err := releasekit.Publish(ctx, request)
			if err != nil {
				fmt.Fprintf(stderr, "publication state=%s phase=%s module=%s module-dir=%s version=%s tag=%s commit=%s tag-object=%s endpoint=%q: %s\n", result.State, result.Phase, result.ModulePath, result.ModuleDir, result.Version, result.Tag, result.CandidateCommit, result.TagObject, result.Endpoint, candidateFailureText(err))
				if errors.Is(err, releasekit.ErrInvalidVersion) {
					return 2
				}
				if result.State == releasekit.PublicationUnknown {
					return 3
				}
				return 1
			}
			fmt.Fprintf(stdout, "published %s as %s at %s (tag object %s)\n", result.Version, result.Tag, result.CandidateCommit, result.TagObject)
			return 0
		}
		candidate, err := releasekit.Check(ctx, request)
		if err != nil {
			fmt.Fprintf(stderr, "check failed module=%s module-dir=%s version=%s tag=%s commit=%s: %s\n", candidate.ModulePath, candidate.ModuleDir, candidate.Version, candidate.Tag, candidate.Commit, candidateFailureText(err))
			if errors.Is(err, releasekit.ErrInvalidVersion) {
				return 2
			}
			return 1
		}
		fmt.Fprintf(stdout, "local candidate module %s version %s tag %s at %s is valid\n", candidate.ModulePath, candidate.Version, candidate.Tag, candidate.Commit)
		return 0
	case cli.BuildAction:
		settings, err := cli.LoadSettings(invocation.Repository, invocation.ConfigPath)
		if err != nil {
			fmt.Fprintf(stderr, "load profile: %v\n", err)
			return 2
		}
		if settings.Build == nil {
			fmt.Fprintln(stderr, "build requires build settings in the profile")
			return 2
		}
		result, err := releasekit.Build(ctx, releasekit.BuildRequest{
			RepositoryDir: invocation.Repository,
			ModuleDir:     settings.ModuleDir,
			Version:       invocation.Version,
			Spec:          *configuredBuildSpec(settings.Build),
			OutputDir:     invocation.OutputDir,
			Output:        stderr,
		})
		if result.OutputDir != "" && len(result.Targets) != 0 {
			if receiptErr := cli.RemoveBuildReceipt(result.OutputDir); receiptErr != nil {
				fmt.Fprintf(stderr, "%v\n", receiptErr)
				return 1
			}
		}
		if err != nil {
			fmt.Fprintf(stderr, "build failed module=%s module-dir=%s version=%s tag=%s commit=%s: %v\n", result.ModulePath, result.ModuleDir, result.Version, result.Tag, result.CandidateCommit, err)
			for _, artifact := range result.Artifacts {
				fmt.Fprintf(stderr, "built %s %s\n", artifact.Filename, artifact.SHA256)
			}
			if errors.Is(err, releasekit.ErrInvalidVersion) {
				return 2
			}
			return 1
		}
		if len(result.Targets) == 0 {
			fmt.Fprintf(stdout, "no build targets selected for module %s version %s tag %s at %s\n", result.ModulePath, result.Version, result.Tag, result.CandidateCommit)
			return 0
		}
		receipt := receiptFromBuild(result)
		receiptPath, err := cli.WriteBuildReceipt(result.OutputDir, receipt)
		if err != nil {
			fmt.Fprintf(stderr, "write build receipt: %v\n", err)
			return 1
		}
		stored, err := cli.LoadBuildReceipt(receiptPath)
		if err != nil {
			fmt.Fprintf(stderr, "verify build receipt: %v\n", err)
			return 1
		}
		if !stored.MatchesBuild(result.RepositoryDir, result.CandidateCommit, result.Version, *settings.Build) {
			fmt.Fprintln(stderr, "build receipt does not match the selected source and build settings")
			return 1
		}
		fmt.Fprintf(stdout, "built %d artifacts for module %s version %s tag %s at %s with %s\n", len(result.Artifacts), result.ModulePath, result.Version, result.Tag, result.CandidateCommit, result.Compiler)
		for _, artifact := range result.Artifacts {
			fmt.Fprintf(stdout, "%s %s\n", artifact.Filename, artifact.SHA256)
		}
		fmt.Fprintf(stdout, "build receipt: %s\n", receiptPath)
		return 0
	case cli.DeliveryAction:
		return runDelivery(ctx, invocation, stdout, stderr)
	case cli.CIDeliveryAction:
		return runCIDelivery(ctx, invocation, stdout, stderr)
	}
	return 2
}

func candidateRequest(invocation cli.Invocation, settings cli.Settings, output io.Writer) releasekit.ReleaseRequest {
	request := releasekit.ReleaseRequest{
		RepositoryDir: invocation.Repository,
		ModuleDir:     settings.ModuleDir,
		Product:       settings.Product,
		Version:       invocation.Version,
		Remote:        settings.Remote,
		Validation:    validationSpec(settings.Validation),
		Build:         configuredBuildSpec(settings.Build),
		Output:        output,
	}
	if len(settings.Checks) != 0 {
		checks := settings.Checks
		request.AdditionalChecks = func(ctx context.Context, candidate releasekit.Candidate) error {
			return cli.RunChecks(ctx, candidate.ModuleDir, checks, map[string]string{
				"RELEASEKIT_VERSION":        candidate.Version,
				"RELEASEKIT_CANDIDATE":      candidate.Commit,
				"RELEASEKIT_REPOSITORY_DIR": candidate.RepositoryDir,
				"RELEASEKIT_MODULE_DIR":     candidate.ModuleDir,
				"RELEASEKIT_MODULE_PATH":    candidate.ModulePath,
				"RELEASEKIT_TAG":            candidate.Tag,
			}, output, output)
		}
	}
	return request
}

func validationSpec(settings *cli.ValidationSettings) releasekit.ValidationSpec {
	if settings == nil {
		return releasekit.ValidationSpec{}
	}
	result := releasekit.ValidationSpec{
		SharedFiles: copyStringsPreservingEmpty(settings.SharedFiles),
		GoFormat:    settings.GoFormat,
		ModuleDistribution: releasekit.ModuleDistributionValidationSpec{
			WorkspaceFiles:    settings.ModuleDistribution.WorkspaceFiles,
			LocalReplacements: settings.ModuleDistribution.LocalReplacements,
		},
		Go: releasekit.GoValidationSpec{
			Race:           settings.Go.Race,
			FullVet:        settings.Go.FullVet,
			CompileTargets: make([]releasekit.Target, len(settings.Go.CompileTargets)),
		},
	}
	if settings.Markdown != nil {
		result.Markdown = &releasekit.MarkdownValidationSpec{
			EnforceCheckoutBoundary: settings.Markdown.EnforceCheckoutBoundary,
		}
	}
	if settings.FileSize != nil {
		var limitBytes *int64
		if settings.FileSize.LimitBytes != nil {
			limit := *settings.FileSize.LimitBytes
			limitBytes = &limit
		}
		result.FileSize = &releasekit.FileSizeValidationSpec{
			LimitBytes: limitBytes,
			Exclusions: append([]string(nil), settings.FileSize.Exclusions...),
		}
	}
	for index, target := range settings.Go.CompileTargets {
		goos, goarch, _ := strings.Cut(target, "/")
		result.Go.CompileTargets[index] = releasekit.Target{OS: goos, Arch: goarch}
	}
	return result
}

func candidateFailureText(err error) string {
	return err.Error()
}

func checkExpectedModule(repositoryDir, expectedModule, profileModule string) error {
	if expectedModule == "" {
		return nil
	}
	expected, err := releaseidentity.ResolveSelection(repositoryDir, expectedModule)
	if err != nil {
		return fmt.Errorf("normalize expected module %q: %w", expectedModule, err)
	}
	selected, err := releaseidentity.ResolveSelection(repositoryDir, profileModule)
	if err != nil {
		return fmt.Errorf("normalize profile module %q: %w", profileModule, err)
	}
	if expected.ModuleSubdir != selected.ModuleSubdir {
		return fmt.Errorf("expected module %q resolves to %q, but the profile selects %q", expectedModule, expected.ModuleSubdir, selected.ModuleSubdir)
	}
	return nil
}

func selectedModuleLabel(moduleDir string) string {
	if moduleDir == "" {
		return "."
	}
	return moduleDir
}

func copyStringsPreservingEmpty(values []string) []string {
	if values == nil {
		return nil
	}
	return append([]string{}, values...)
}

func runDelivery(ctx context.Context, invocation cli.Invocation, stdout, stderr io.Writer) int {
	settings, err := cli.LoadSettings(invocation.Repository, invocation.ConfigPath)
	if err != nil {
		fmt.Fprintf(stderr, "load profile: %v\n", err)
		return 2
	}
	return deliverWithSettings(ctx, invocation, settings, stdout, stderr)
}

func runCIDelivery(ctx context.Context, invocation cli.Invocation, stdout, stderr io.Writer) int {
	err := releasekit.PrepareTaggedCheckout(ctx, releasekit.TaggedCheckoutRequest{
		RepositoryDir:  invocation.Repository,
		Tag:            invocation.ExpectedTag,
		Remote:         invocation.Remote,
		ExpectedCommit: invocation.Commit,
		VerifyOnly:     invocation.Prepared,
	})
	if err != nil {
		fmt.Fprintf(stderr, "prepare tagged checkout: %v\n", err)
		if errors.Is(err, releasekit.ErrInvalidVersion) {
			return 2
		}
		return 1
	}

	settings, err := cli.LoadSettings(invocation.Repository, invocation.ConfigPath)
	if err != nil {
		fmt.Fprintf(stderr, "load profile: %v\n", err)
		return 2
	}
	if err := checkExpectedModule(invocation.Repository, invocation.ExpectedModule, settings.ModuleDir); err != nil {
		fmt.Fprintf(stderr, "profile module selection: %v\n", err)
		return 2
	}
	destination, status := deliveryDestination(settings, stderr)
	if status != 0 {
		return status
	}
	if settings.Build != nil && len(settings.Build.Targets) != 0 {
		if err := releasekit.PrepareBuildDependencies(ctx, releasekit.DependencyPreparationRequest{
			RepositoryDir: invocation.Repository,
			ModuleDir:     settings.ModuleDir,
		}); err != nil {
			fmt.Fprintf(stderr, "prepare build dependencies: %v\n", err)
			return 1
		}
	}
	return deliverWithDestination(ctx, invocation, settings, destination, stdout, stderr)
}

// deliverWithSettings adapts prepared CLI state to the public delivery facade.
// CI entry points can reuse it after preparing the checkout and loading its profile.
func deliverWithSettings(ctx context.Context, invocation cli.Invocation, settings cli.Settings, stdout, stderr io.Writer) int {
	destination, status := deliveryDestination(settings, stderr)
	if status != 0 {
		return status
	}
	return deliverWithDestination(ctx, invocation, settings, destination, stdout, stderr)
}

func deliveryDestination(settings cli.Settings, stderr io.Writer) (releasekit.GiteaDestination, int) {
	delivery := settings.Delivery
	if delivery == nil || strings.TrimSpace(delivery.BaseURL) == "" || strings.TrimSpace(delivery.Owner) == "" || strings.TrimSpace(delivery.Repository) == "" {
		fmt.Fprintln(stderr, "deliver requires base_url, owner, and repository in the profile delivery settings")
		return releasekit.GiteaDestination{}, 2
	}
	tokenEnv := delivery.TokenEnv
	if strings.TrimSpace(tokenEnv) == "" {
		tokenEnv = "RELEASEKIT_GITEA_TOKEN"
	}
	token, ok := os.LookupEnv(tokenEnv)
	if !ok || strings.TrimSpace(token) == "" {
		fmt.Fprintf(stderr, "deliver requires a non-empty token in environment variable %s\n", tokenEnv)
		return releasekit.GiteaDestination{}, 2
	}
	return releasekit.GiteaDestination{BaseURL: delivery.BaseURL, Owner: delivery.Owner, Repository: delivery.Repository, Token: token}, 0
}

func deliverWithDestination(ctx context.Context, invocation cli.Invocation, settings cli.Settings, destination releasekit.GiteaDestination, stdout, stderr io.Writer) int {
	hasTargets := settings.Build != nil && len(settings.Build.Targets) != 0
	if invocation.AssetsDir != "" && !hasTargets {
		fmt.Fprintln(stderr, "--assets requires build targets in the profile")
		return 2
	}
	var buildSpec *releasekit.BuildSpec
	var prebuilt *releasekit.BuildResult
	if invocation.AssetsDir == "" && settings.Build != nil {
		buildSpec = configuredBuildSpec(settings.Build)
	}
	if hasTargets {
		if invocation.AssetsDir != "" {
			selection, err := releaseidentity.ResolveSelection(invocation.Repository, settings.ModuleDir)
			if err != nil {
				fmt.Fprintf(stderr, "resolve asset module directory: %v\n", err)
				return 1
			}
			assetsDir := artifact.OutputDirectory(selection.ModuleDir, invocation.AssetsDir)
			receipt, err := cli.LoadBuildReceipt(filepath.Join(assetsDir, cli.BuildReceiptName))
			if err != nil {
				fmt.Fprintf(stderr, "load verified build receipt: %v\n", err)
				return 1
			}
			if !receipt.MatchesBuild(invocation.Repository, receipt.CandidateCommit, invocation.Version, *settings.Build) {
				fmt.Fprintln(stderr, "build receipt does not match the selected repository, version, or build settings")
				return 1
			}
			prebuilt = buildResultFromReceipt(receipt)
		}
	}

	result, err := releasekit.Deliver(ctx, releasekit.DeliveryRequest{
		RepositoryDir: invocation.Repository,
		ModuleDir:     settings.ModuleDir,
		Product:       settings.Product,
		Version:       invocation.Version,
		ExpectedTag:   invocation.ExpectedTag,
		Destination:   destination,
		Build:         buildSpec,
		Prebuilt:      prebuilt,
		Output:        stderr,
	})
	if err != nil {
		fmt.Fprintf(stderr, "delivery state=%s module=%s module-dir=%s version=%s tag=%s commit=%s url=%s: %v\n", result.State, result.ModulePath, result.ModuleDir, result.Version, result.Tag, result.CandidateCommit, result.ReleaseURL, err)
		writeDeliveryAssets(stderr, result)
		writeDeliveryRecovery(stderr, result)
		if errors.Is(err, releasekit.ErrInvalidVersion) {
			return 2
		}
		if result.State == releasekit.DeliveryUnknown {
			return 3
		}
		return 1
	}
	fmt.Fprintf(stdout, "delivered module %s version %s tag %s at %s (state %s)\n", result.ModulePath, result.Version, result.Tag, result.CandidateCommit, result.State)
	if result.ReleaseURL != "" {
		fmt.Fprintf(stdout, "release: %s\n", result.ReleaseURL)
	}
	writeDeliveryAssets(stdout, result)
	return 0
}

func writeDeliveryAssets(output io.Writer, result releasekit.DeliveryResult) {
	for _, group := range []struct {
		label  string
		assets []releasekit.DeliveryAsset
	}{{"matching", result.Matching}, {"uploaded", result.Uploaded}, {"pending", result.Pending}, {"conflicting", result.Conflicting}, {"uncertain", result.Uncertain}} {
		for _, asset := range group.assets {
			fmt.Fprintf(output, "%s %s %s\n", group.label, asset.Filename, asset.SHA256)
		}
	}
}

func writeDeliveryRecovery(output io.Writer, result releasekit.DeliveryResult) {
	switch result.State {
	case releasekit.DeliveryNotAttempted:
		fmt.Fprintf(output, "recovery: fix the local or preflight failure for module %s version %s tag %s before retrying; no remote write was attempted\n", result.ModulePath, result.Version, result.Tag)
	case releasekit.DeliveryPartial:
		fmt.Fprintf(output, "recovery: fix the reported cause, then retry module %s version %s tag %s\n", result.ModulePath, result.Version, result.Tag)
	case releasekit.DeliveryConflict:
		fmt.Fprintf(output, "recovery: investigate conflicting hosted content for module %s version %s tag %s; use a new version if the source or published contents need correction\n", result.ModulePath, result.Version, result.Tag)
	case releasekit.DeliveryUnknown:
		fmt.Fprintf(output, "recovery: resolve the remote state for module %s version %s tag %s before retrying\n", result.ModulePath, result.Version, result.Tag)
	default:
		return
	}
	if len(result.Matching)+len(result.Uploaded)+len(result.Conflicting)+len(result.Uncertain) != 0 {
		fmt.Fprintln(output, "if rebuilding could change asset bytes already on the server, retain the original build artifacts and retry with deliver --assets DIR")
	}
}

func buildResultFromReceipt(receipt cli.BuildReceipt) *releasekit.BuildResult {
	result := &releasekit.BuildResult{
		RepositoryDir: receipt.RepositoryDir, ModuleDir: receipt.ModuleDir, ModulePath: receipt.ModulePath, Tag: receipt.Tag,
		CandidateCommit: receipt.CandidateCommit, SourceVerified: receipt.SourceVerified,
		Version: receipt.Version, MainPackage: receipt.MainPackage, BinaryName: receipt.BinaryName,
		OutputDir: receipt.OutputDir, Compiler: receipt.Compiler,
	}
	for _, target := range receipt.Targets {
		result.Targets = append(result.Targets, releasekit.Target{OS: target.OS, Arch: target.Arch})
	}
	for _, artifact := range receipt.Artifacts {
		result.Artifacts = append(result.Artifacts, releasekit.BuildArtifact{
			Path: artifact.Path, Filename: artifact.Filename,
			Target: releasekit.Target{OS: artifact.Target.OS, Arch: artifact.Target.Arch}, SHA256: artifact.SHA256,
		})
	}
	return result
}

func configuredBuildSpec(settings *cli.BuildSettings) *releasekit.BuildSpec {
	if settings == nil {
		return nil
	}
	spec := &releasekit.BuildSpec{
		MainPackage: settings.MainPackage,
		BinaryName:  settings.BinaryName,
		Targets:     make([]releasekit.Target, 0, len(settings.Targets)),
	}
	for _, value := range settings.Targets {
		goos, goarch, _ := strings.Cut(value, "/")
		spec.Targets = append(spec.Targets, releasekit.Target{OS: goos, Arch: goarch})
	}
	return spec
}

func receiptFromBuild(result releasekit.BuildResult) cli.BuildReceipt {
	receipt := cli.BuildReceipt{
		SchemaVersion:   cli.BuildReceiptSchemaVersion,
		RepositoryDir:   result.RepositoryDir,
		ModuleDir:       result.ModuleDir,
		ModulePath:      result.ModulePath,
		Tag:             result.Tag,
		CandidateCommit: result.CandidateCommit,
		SourceVerified:  result.SourceVerified,
		Version:         result.Version,
		MainPackage:     result.MainPackage,
		BinaryName:      result.BinaryName,
		OutputDir:       result.OutputDir,
		Compiler:        result.Compiler,
		Targets:         make([]cli.ReceiptTarget, 0, len(result.Targets)),
		Artifacts:       make([]cli.ReceiptArtifact, 0, len(result.Artifacts)),
	}
	for _, target := range result.Targets {
		receipt.Targets = append(receipt.Targets, cli.ReceiptTarget{OS: target.OS, Arch: target.Arch})
	}
	for _, artifact := range result.Artifacts {
		receipt.Artifacts = append(receipt.Artifacts, cli.ReceiptArtifact{
			Path:     artifact.Path,
			Filename: artifact.Filename,
			Target:   cli.ReceiptTarget{OS: artifact.Target.OS, Arch: artifact.Target.Arch},
			SHA256:   artifact.SHA256,
		})
	}
	return receipt
}