package main

import (
	"errors"
	"net/http"
	"strings"
	"time"

	"github.com/go-chi/chi/v5"
)

const (
	themeDeployConfirmation  = "DEPLOY"
	themeDeployStatusSuccess = "success"
	themeDeployStatusFailed  = "failed"
)

type keycloakThemeDeploymentRequest struct {
	Summary      string `json:"summary"`
	Confirmation string `json:"confirmation"`
}

func (a *app) deployKeycloakTheme(w http.ResponseWriter, r *http.Request) {
	claims, _ := r.Context().Value(userClaimsKey).(*accessClaims)
	if !hasPermission(claims, permKeycloakThemesDeploy) {
		writeError(w, http.StatusForbidden, "missing permission: keycloak_themes.deploy")
		return
	}

	if !a.cfg.KeycloakThemeDeployEnabled {
		writeError(w, http.StatusServiceUnavailable, "theme deployment is disabled")
		return
	}

	themeID := strings.TrimSpace(chi.URLParam(r, "id"))
	if themeID == "" {
		writeError(w, http.StatusBadRequest, "id is required")
		return
	}

	var payload keycloakThemeDeploymentRequest
	if err := decodeJSON(r, &payload); err != nil {
		writeError(w, http.StatusBadRequest, "invalid payload")
		return
	}
	if err := validateThemeDeploymentRequest(payload); err != nil {
		writeError(w, http.StatusBadRequest, err.Error())
		return
	}

	theme, err := a.getByID("keycloak_themes", themeID)
	if err != nil {
		if errors.Is(err, ErrNotFound) {
			writeError(w, http.StatusNotFound, "resource not found")
			return
		}
		writeError(w, http.StatusInternalServerError, "failed to load keycloak theme")
		return
	}

	status, _ := theme["status"].(string)
	if strings.TrimSpace(strings.ToLower(status)) != keycloakThemeStatusPublished {
		writeError(w, http.StatusBadRequest, "only published themes can be deployed")
		return
	}

	actor := resolveThemeActor(claims)
	deploymentKey := keycloakThemeDeploymentKey(theme)

	current, err := a.getCurrentThemeDeployment(deploymentKey)
	if err != nil {
		a.recordThemeDeploymentAudit(theme, payload.Summary, actor, themeDeployStatusFailed, nil, "failed to resolve deployment state")
		writeError(w, http.StatusInternalServerError, "failed to deploy keycloak theme")
		return
	}

	rollback := buildThemeDeploymentRollback(current)
	if err := a.upsertCurrentThemeDeployment(deploymentKey, theme, actor, rollback); err != nil {
		a.recordThemeDeploymentAudit(theme, payload.Summary, actor, themeDeployStatusFailed, rollback, "failed to persist deployment state")
		writeError(w, http.StatusInternalServerError, "failed to deploy keycloak theme")
		return
	}

	a.recordThemeDeploymentAudit(theme, payload.Summary, actor, themeDeployStatusSuccess, rollback, "")
	writeJSON(w, http.StatusOK, Doc{
		"status":          "deployed",
		"themeId":         strings.TrimSpace(themeID),
		"rollbackThemeId": rollback["themeId"],
		"rollbackVersion": rollback["version"],
	})
}

func validateThemeDeploymentRequest(payload keycloakThemeDeploymentRequest) error {
	if strings.TrimSpace(payload.Summary) == "" {
		return errors.New("deployment summary is required")
	}
	if strings.TrimSpace(strings.ToUpper(payload.Confirmation)) != themeDeployConfirmation {
		return errors.New("deployment confirmation must be DEPLOY")
	}
	return nil
}

func resolveThemeActor(claims *accessClaims) string {
	if claims == nil {
		return "unknown"
	}
	if value := strings.TrimSpace(claims.PreferredUsername); value != "" {
		return value
	}
	if value := strings.TrimSpace(claims.Email); value != "" {
		return value
	}
	if value := strings.TrimSpace(claims.Sub); value != "" {
		return value
	}
	return "unknown"
}

func keycloakThemeDeploymentKey(theme Doc) string {
	target, _ := theme["target"].(Doc)
	realm, _ := target["realm"].(string)
	client, _ := target["client"].(string)
	organizationID, _ := target["organizationId"].(string)
	themeType, _ := theme["type"].(string)
	scope, _ := theme["scope"].(string)

	parts := []string{
		"realm=" + strings.TrimSpace(realm),
		"client=" + strings.TrimSpace(client),
		"scope=" + strings.TrimSpace(scope),
		"organization=" + strings.TrimSpace(organizationID),
		"type=" + strings.TrimSpace(themeType),
	}
	return strings.Join(parts, "|")
}

func buildThemeDeploymentRollback(current Doc) Doc {
	if current == nil {
		return Doc{}
	}
	rollback := Doc{}
	if themeID, ok := current["themeId"].(string); ok && strings.TrimSpace(themeID) != "" {
		rollback["themeId"] = strings.TrimSpace(themeID)
	}
	if version, ok := current["version"].(string); ok && strings.TrimSpace(version) != "" {
		rollback["version"] = strings.TrimSpace(version)
	}
	if len(rollback) == 0 {
		return Doc{}
	}
	return rollback
}

func (a *app) getCurrentThemeDeployment(deploymentKey string) (Doc, error) {
	entries, err := a.list("keycloak_theme_deployments_current", Doc{"deploymentKey": deploymentKey}, nil)
	if err != nil {
		return nil, err
	}
	if len(entries) == 0 {
		return nil, nil
	}
	return entries[0], nil
}

func (a *app) upsertCurrentThemeDeployment(deploymentKey string, theme Doc, actor string, rollback Doc) error {
	target, _ := theme["target"].(Doc)
	now := time.Now().UnixMilli()
	doc := Doc{
		"deploymentKey":  deploymentKey,
		"themeId":        strings.TrimSpace(anyToString(theme["id"])),
		"version":        strings.TrimSpace(anyToString(theme["version"])),
		"scope":          strings.TrimSpace(anyToString(theme["scope"])),
		"type":           strings.TrimSpace(anyToString(theme["type"])),
		"realm":          strings.TrimSpace(anyToString(target["realm"])),
		"client":         strings.TrimSpace(anyToString(target["client"])),
		"organizationId": strings.TrimSpace(anyToString(target["organizationId"])),
		"deployedBy":     strings.TrimSpace(actor),
		"deployedAt":     now,
		"rollback":       rollback,
	}

	current, err := a.getCurrentThemeDeployment(deploymentKey)
	if err != nil {
		return err
	}
	if current == nil {
		_, err = a.create("keycloak_theme_deployments_current", doc)
		return err
	}
	_, err = a.patch("keycloak_theme_deployments_current", strings.TrimSpace(anyToString(current["id"])), doc)
	return err
}

func (a *app) recordThemeDeploymentAudit(theme Doc, summary, actor, status string, rollback Doc, errorMessage string) {
	audit := buildThemeDeploymentAuditDoc(theme, summary, actor, status, rollback, errorMessage)
	_, _ = a.create("keycloak_theme_deployments_audit", audit)
}

func buildThemeDeploymentAuditDoc(theme Doc, summary, actor, status string, rollback Doc, errorMessage string) Doc {
	audit := Doc{
		"themeId":   strings.TrimSpace(anyToString(theme["id"])),
		"themeSlug": strings.TrimSpace(anyToString(theme["slug"])),
		"version":   strings.TrimSpace(anyToString(theme["version"])),
		"scope":     strings.TrimSpace(anyToString(theme["scope"])),
		"type":      strings.TrimSpace(anyToString(theme["type"])),
		"status":    strings.TrimSpace(status),
		"summary":   strings.TrimSpace(summary),
		"actor":     strings.TrimSpace(actor),
		"rollback":  rollback,
	}
	if errorMessage != "" {
		audit["errorMessage"] = strings.TrimSpace(errorMessage)
	}
	return audit
}

func anyToString(value any) string {
	if value == nil {
		return ""
	}
	if raw, ok := value.(string); ok {
		return raw
	}
	return ""
}