package cli

import (
	"context"
	"errors"
	"fmt"
	"os"
	"path/filepath"
	"runtime"
	"strings"
	"time"

	frameworkcli "gitea.lclr.dev/AI/mcp-framework/cli"
	frameworkconfig "gitea.lclr.dev/AI/mcp-framework/config"
	frameworkmanifest "gitea.lclr.dev/AI/mcp-framework/manifest"
	frameworkupdate "gitea.lclr.dev/AI/mcp-framework/update"
)

func (a *App) runDoctor(ctx context.Context, args []string) error {
	profileFlag, err := parseProfileArgs("doctor", args)
	if err != nil {
		return err
	}
	if a.configStore == nil {
		return fmt.Errorf("config store is not configured")
	}
	if a.openSecretStore == nil {
		return fmt.Errorf("secret store is not configured")
	}
	if a.newMailService == nil {
		return fmt.Errorf("mail service is not configured")
	}

	metadata := a.runtimeMetadata()
	report := frameworkcli.RunDoctor(ctx, frameworkcli.DoctorOptions{
		ConfigCheck:      frameworkcli.NewConfigCheck(frameworkconfig.NewStore[ProfileConfig](binaryName)),
		SecretStoreCheck: frameworkcli.SecretStoreAvailabilityCheck(a.openSecretStore),
		ManifestDir:      a.doctorManifestDir(),
		ManifestValidator: func(file frameworkmanifest.File, _ string) []string {
			return validateManifestUpdate(file, metadata.BinaryName)
		},
		ConnectivityCheck: a.doctorConnectivityCheck(profileFlag),
		ExtraChecks: []frameworkcli.DoctorCheck{
			a.doctorRequiredProfileFieldsCheck(profileFlag),
			a.doctorPasswordCheck(profileFlag),
		},
	})
	if err := frameworkcli.RenderDoctorReport(a.stdout, report); err != nil {
		return err
	}
	if report.HasFailures() {
		return fmt.Errorf("doctor checks failed")
	}
	return nil
}

func (a *App) doctorManifestDir() string {
	if a.resolveExecutable == nil {
		return "."
	}

	executablePath, err := a.resolveExecutable()
	if err != nil {
		return "."
	}
	return filepath.Dir(executablePath)
}

func (a *App) doctorRequiredProfileFieldsCheck(profileFlag string) frameworkcli.DoctorCheck {
	var (
		profileValues map[string]string
		loadErr       error
	)

	check := frameworkcli.RequiredResolvedFieldsCheck(frameworkcli.ResolveOptions{
		Fields: profileFieldSpecs(),
		Lookup: frameworkcli.ResolveLookup(frameworkcli.ResolveLookupOptions{
			Env: frameworkcli.EnvLookup(os.LookupEnv),
			Config: func(key string) (string, bool, error) {
				if loadErr != nil {
					return "", false, loadErr
				}
				if profileValues == nil {
					cfg, _, err := a.configStore.LoadDefault()
					if err != nil {
						loadErr = err
						return "", false, loadErr
					}

					profileName := a.resolveProfileName(profileFlag, cfg.CurrentProfile)
					profile := cfg.Profiles[profileName]
					profileValues = map[string]string{
						"host":     profile.Host,
						"username": profile.Username,
					}
				}

				return frameworkcli.MapLookup(profileValues)(key)
			},
		}),
	})

	return func(ctx context.Context) frameworkcli.DoctorResult {
		result := check(ctx)
		result.Name = "profile"
		return result
	}
}

func (a *App) doctorPasswordCheck(profileFlag string) frameworkcli.DoctorCheck {
	return func(context.Context) frameworkcli.DoctorResult {
		profileName := a.resolveDoctorProfileName(profileFlag)
		store, err := a.openSecretStore()
		if err != nil {
			return frameworkcli.DoctorResult{
				Name:    "password",
				Status:  frameworkcli.DoctorStatusFail,
				Summary: "cannot inspect stored password",
				Detail:  err.Error(),
			}
		}

		resolution, err := resolveCredentialFields(
			ProfileConfig{},
			store,
			[]frameworkcli.FieldSpec{passwordFieldSpec(profileName)},
		)
		if err != nil {
			var missingErr *frameworkcli.MissingRequiredValuesError
			if errors.As(err, &missingErr) {
				return frameworkcli.DoctorResult{
					Name:    "password",
					Status:  frameworkcli.DoctorStatusFail,
					Summary: "stored password is missing",
					Detail: fmt.Sprintf(
						"set %q or secret %q",
						passwordEnv,
						passwordSecretName(profileName),
					),
				}
			}

			return frameworkcli.DoctorResult{
				Name:    "password",
				Status:  frameworkcli.DoctorStatusFail,
				Summary: "cannot read stored password",
				Detail:  err.Error(),
			}
		}

		password, _ := resolution.Get("password")
		if password.Source == frameworkcli.SourceEnv {
			return frameworkcli.DoctorResult{
				Name:    "password",
				Status:  frameworkcli.DoctorStatusOK,
				Summary: "password is provided via environment",
				Detail:  fmt.Sprintf("variable %q", passwordEnv),
			}
		}

		return frameworkcli.DoctorResult{
			Name:    "password",
			Status:  frameworkcli.DoctorStatusOK,
			Summary: "stored password is present",
			Detail:  fmt.Sprintf("secret %q", passwordSecretName(profileName)),
		}
	}
}

func (a *App) doctorConnectivityCheck(profileFlag string) frameworkcli.DoctorCheck {
	return func(parent context.Context) frameworkcli.DoctorResult {
		ctx, cancel := context.WithTimeout(parent, 35*time.Second)
		defer cancel()

		cred, err := a.loadCredential(profileFlag)
		if err != nil {
			return frameworkcli.DoctorResult{
				Name:    "connectivity",
				Status:  frameworkcli.DoctorStatusFail,
				Summary: "cannot load IMAP credentials",
				Detail:  err.Error(),
			}
		}

		if _, err := a.newMailService().ListMailboxes(ctx, cred); err != nil {
			return frameworkcli.DoctorResult{
				Name:    "connectivity",
				Status:  frameworkcli.DoctorStatusFail,
				Summary: "IMAP server is unreachable or rejected authentication",
				Detail:  err.Error(),
			}
		}

		return frameworkcli.DoctorResult{
			Name:    "connectivity",
			Status:  frameworkcli.DoctorStatusOK,
			Summary: "IMAP server is reachable",
		}
	}
}

func (a *App) resolveDoctorProfileName(profileFlag string) string {
	if a.configStore == nil {
		return a.resolveProfileName(profileFlag, "")
	}

	cfg, _, err := a.configStore.LoadDefault()
	if err != nil {
		return a.resolveProfileName(profileFlag, "")
	}

	return a.resolveProfileName(profileFlag, cfg.CurrentProfile)
}

func validateManifestUpdate(file frameworkmanifest.File, runtimeBinaryName string) []string {
	source := file.Update.ReleaseSource()
	issues := make([]string, 0, 2)

	if _, err := frameworkupdate.ResolveLatestReleaseURL("", source); err != nil {
		issues = append(issues, err.Error())
	}

	binary := strings.TrimSpace(runtimeBinaryName)
	if binary == "" {
		binary = strings.TrimSpace(file.BinaryName)
	}
	if binary == "" {
		binary = binaryName
	}

	if _, err := frameworkupdate.AssetNameWithTemplate(binary, runtime.GOOS, runtime.GOARCH, source.AssetNameTemplate); err != nil {
		issues = append(issues, err.Error())
	}

	return issues
}