package handlers

import (
	"context"
	"encoding/json"
	"fmt"
	"net/http"
	"time"

	"github.com/go-chi/chi/v5"
	"github.com/orchard9/rdev/internal/domain"
	"github.com/orchard9/rdev/pkg/api"
)

// maxReplicas is the maximum number of deployment replicas allowed.
const maxReplicas = 10

// DeployRequest is the request body for POST /projects/{id}/deploy.
type DeployRequest struct {
	Image    string            `json:"image"`              // Container image
	Domain   string            `json:"domain,omitempty"`   // Custom domain (optional)
	Port     int               `json:"port,omitempty"`     // Container port (default 8080)
	Replicas int               `json:"replicas,omitempty"` // Number of replicas (default 1)
	EnvVars  map[string]string `json:"env_vars,omitempty"` // Plain environment variables
	Secrets  map[string]string `json:"secrets,omitempty"`  // Secret environment variables
}

// DeployResponse is the response for POST /projects/{id}/deploy.
type DeployResponse struct {
	ProjectName string `json:"project_name"`
	Image       string `json:"image"`
	Domain      string `json:"domain"`
	URL         string `json:"url"`
	Status      string `json:"status"`
}

// Deploy deploys a project.
// POST /projects/{id}/deploy
func (h *InfrastructureHandler) Deploy(w http.ResponseWriter, r *http.Request) {
	projectID := chi.URLParam(r, "id")
	ctx, cancel := context.WithTimeout(r.Context(), 60*time.Second)
	defer cancel()

	// Validate project ID
	if err := validateProjectID(projectID); err != nil {
		api.WriteBadRequest(w, r, err.Error())
		return
	}

	if h.deployer == nil {
		api.WriteInternalError(w, r, "deployer not configured")
		return
	}

	var req DeployRequest
	if err := json.NewDecoder(r.Body).Decode(&req); err != nil {
		api.WriteBadRequest(w, r, "invalid request body")
		return
	}

	if req.Image == "" {
		api.WriteBadRequest(w, r, "image is required")
		return
	}

	// Build domain
	deployDomain := req.Domain
	if deployDomain == "" {
		deployDomain = projectID + "." + h.defaultDomain
	}

	// Create DNS record if DNS provider is configured
	if h.dns != nil && h.clusterIP != "" {
		_, err := h.dns.CreateRecord(ctx, domain.DNSRecord{
			Type:    "A",
			Name:    projectID,
			Content: h.clusterIP,
			TTL:     1,
			Proxied: false,
		})
		if err != nil {
			// Check if this is a "record already exists" error (not a real failure)
			// Cloudflare returns specific error codes we could check, but for now
			// we log and continue - the record might already exist from a previous deploy
			// TODO: Add proper duplicate detection once we have structured errors from adapter
			_ = err // acknowledge error - may be duplicate record which is acceptable
		}
	}

	// Deploy
	spec := domain.DeploySpec{
		ProjectName: projectID,
		Image:       req.Image,
		Domain:      deployDomain,
		Port:        req.Port,
		Replicas:    req.Replicas,
		EnvVars:     req.EnvVars,
		Secrets:     req.Secrets,
	}

	if err := h.deployer.Deploy(ctx, spec); err != nil {
		api.WriteInternalError(w, r, fmt.Sprintf("failed to deploy: %v", err))
		return
	}

	api.WriteCreated(w, r, DeployResponse{
		ProjectName: projectID,
		Image:       req.Image,
		Domain:      deployDomain,
		URL:         "https://" + deployDomain,
		Status:      "deploying",
	})
}

// GetDeployStatus returns the deployment status for a project.
// GET /projects/{id}/deploy/status
func (h *InfrastructureHandler) GetDeployStatus(w http.ResponseWriter, r *http.Request) {
	projectID := chi.URLParam(r, "id")
	ctx, cancel := context.WithTimeout(r.Context(), 10*time.Second)
	defer cancel()

	if h.deployer == nil {
		api.WriteInternalError(w, r, "deployer not configured")
		return
	}

	status, err := h.deployer.GetStatus(ctx, projectID)
	if err != nil {
		api.WriteInternalError(w, r, fmt.Sprintf("failed to get status: %v", err))
		return
	}

	if status == nil {
		api.WriteNotFound(w, r, fmt.Sprintf("no deployment found for project: %s", projectID))
		return
	}

	api.WriteSuccess(w, r, map[string]any{
		"project_name":   status.ProjectName,
		"image":          status.Image,
		"replicas":       status.Replicas,
		"ready_replicas": status.ReadyReplicas,
		"url":            status.URL,
		"status":         status.Status,
		"created_at":     status.CreatedAt,
		"updated_at":     status.UpdatedAt,
	})
}

// Undeploy removes the deployment for a project.
// DELETE /projects/{id}/deploy
func (h *InfrastructureHandler) Undeploy(w http.ResponseWriter, r *http.Request) {
	projectID := chi.URLParam(r, "id")
	ctx, cancel := context.WithTimeout(r.Context(), 30*time.Second)
	defer cancel()

	if h.deployer == nil {
		api.WriteInternalError(w, r, "deployer not configured")
		return
	}

	if err := h.deployer.Undeploy(ctx, projectID); err != nil {
		api.WriteInternalError(w, r, fmt.Sprintf("failed to undeploy: %v", err))
		return
	}

	// Remove DNS record if DNS provider is configured
	if h.dns != nil {
		_ = h.dns.DeleteRecordByName(ctx, "A", projectID)
	}

	api.WriteSuccess(w, r, map[string]string{
		"status":  "undeployed",
		"project": projectID,
	})
}

// RestartDeploy restarts the deployment for a project.
// POST /projects/{id}/deploy/restart
func (h *InfrastructureHandler) RestartDeploy(w http.ResponseWriter, r *http.Request) {
	projectID := chi.URLParam(r, "id")
	ctx, cancel := context.WithTimeout(r.Context(), 30*time.Second)
	defer cancel()

	if h.deployer == nil {
		api.WriteInternalError(w, r, "deployer not configured")
		return
	}

	if err := h.deployer.Restart(ctx, projectID); err != nil {
		api.WriteInternalError(w, r, fmt.Sprintf("failed to restart: %v", err))
		return
	}

	api.WriteSuccess(w, r, map[string]string{
		"status":  "restarting",
		"project": projectID,
	})
}

// ScaleRequest is the request body for POST /projects/{id}/deploy/scale.
type ScaleRequest struct {
	Replicas int `json:"replicas"`
}

// ScaleDeploy scales the deployment for a project.
// POST /projects/{id}/deploy/scale
func (h *InfrastructureHandler) ScaleDeploy(w http.ResponseWriter, r *http.Request) {
	projectID := chi.URLParam(r, "id")
	ctx, cancel := context.WithTimeout(r.Context(), 30*time.Second)
	defer cancel()

	if h.deployer == nil {
		api.WriteInternalError(w, r, "deployer not configured")
		return
	}

	var req ScaleRequest
	if err := json.NewDecoder(r.Body).Decode(&req); err != nil {
		api.WriteBadRequest(w, r, "invalid request body")
		return
	}

	if req.Replicas < 0 || req.Replicas > maxReplicas {
		api.WriteBadRequest(w, r, fmt.Sprintf("replicas must be between 0 and %d", maxReplicas))
		return
	}

	if err := h.deployer.Scale(ctx, projectID, req.Replicas); err != nil {
		api.WriteInternalError(w, r, fmt.Sprintf("failed to scale: %v", err))
		return
	}

	api.WriteSuccess(w, r, map[string]any{
		"status":   "scaled",
		"project":  projectID,
		"replicas": req.Replicas,
	})
}

// GetDeployLogs returns recent logs from the deployment.
// GET /projects/{id}/deploy/logs
func (h *InfrastructureHandler) GetDeployLogs(w http.ResponseWriter, r *http.Request) {
	projectID := chi.URLParam(r, "id")
	ctx, cancel := context.WithTimeout(r.Context(), 30*time.Second)
	defer cancel()

	if h.deployer == nil {
		api.WriteInternalError(w, r, "deployer not configured")
		return
	}

	// Default to 100 lines
	tailLines := 100

	logs, err := h.deployer.GetLogs(ctx, projectID, tailLines)
	if err != nil {
		api.WriteInternalError(w, r, fmt.Sprintf("failed to get logs: %v", err))
		return
	}

	api.WriteSuccess(w, r, map[string]string{
		"project": projectID,
		"logs":    logs,
	})
}