package v1

import (
	"errors"
	"net/http"

	"github.com/gin-gonic/gin"

	"github.com/gochat/gochat/internal/model"
	"github.com/gochat/gochat/internal/service"
	"github.com/gochat/gochat/pkg/response"
)

// SlackIntegrationHandler handles Slack integration endpoints.
// Reference: Chatwoot Integrations::SlackController
type SlackIntegrationHandler struct {
	svc *service.SlackIntegrationService
}

// NewSlackIntegrationHandler creates a new SlackIntegrationHandler.
func NewSlackIntegrationHandler(svc *service.SlackIntegrationService) *SlackIntegrationHandler {
	return &SlackIntegrationHandler{svc: svc}
}

// Create creates a Slack integration for an account.
// POST /api/v1/accounts/:account_id/integrations/slack
func (h *SlackIntegrationHandler) Create(c *gin.Context) {
	accountID, err := parseUintParam(c, "account_id")
	if err != nil {
		response.AbortWithStatusError(c, http.StatusBadRequest, response.ErrBadRequest, "invalid account_id")
		return
	}

	var req service.CreateSlackRequest
	if err := c.ShouldBind(&req); err != nil {
		response.AbortWithStatusError(c, http.StatusBadRequest, response.ErrBadRequest, err.Error())
		return
	}

	hook, svcErr := h.svc.Create(c.Request.Context(), accountID, req)
	if svcErr != nil {
		handleServiceError(c, svcErr)
		return
	}
	c.JSON(http.StatusOK, h.slackAppPayload(c, accountID, []model.IntegrationHook{*hook}))
}

// Update updates a Slack integration for an account.
// PATCH /api/v1/accounts/:account_id/integrations/slack
func (h *SlackIntegrationHandler) Update(c *gin.Context) {
	accountID, err := parseUintParam(c, "account_id")
	if err != nil {
		response.AbortWithStatusError(c, http.StatusBadRequest, response.ErrBadRequest, "invalid account_id")
		return
	}

	var req service.UpdateSlackRequest
	if err := c.ShouldBind(&req); err != nil {
		response.AbortWithStatusError(c, http.StatusBadRequest, response.ErrBadRequest, err.Error())
		return
	}

	hook, svcErr := h.svc.Update(c.Request.Context(), accountID, req)
	if svcErr != nil {
		if errors.Is(svcErr, service.ErrSlackInvalidChannel) {
			c.JSON(http.StatusUnprocessableEntity, gin.H{"error": "Invalid slack channel. Please try again"})
			return
		}
		handleServiceError(c, svcErr)
		return
	}
	c.JSON(http.StatusOK, h.slackAppPayload(c, accountID, []model.IntegrationHook{*hook}))
}

// Delete removes a Slack integration for an account.
// DELETE /api/v1/accounts/:account_id/integrations/slack
func (h *SlackIntegrationHandler) Delete(c *gin.Context) {
	accountID, err := parseUintParam(c, "account_id")
	if err != nil {
		response.AbortWithStatusError(c, http.StatusBadRequest, response.ErrBadRequest, "invalid account_id")
		return
	}

	if svcErr := h.svc.Delete(c.Request.Context(), accountID); svcErr != nil {
		handleServiceError(c, svcErr)
		return
	}
	c.Status(http.StatusOK)
}

// ListAllChannels lists available Slack channels.
// GET /api/v1/accounts/:account_id/integrations/slack/list_all_channels
func (h *SlackIntegrationHandler) ListAllChannels(c *gin.Context) {
	accountID, err := parseUintParam(c, "account_id")
	if err != nil {
		response.AbortWithStatusError(c, http.StatusBadRequest, response.ErrBadRequest, "invalid account_id")
		return
	}

	channels, svcErr := h.svc.ListAllChannels(c.Request.Context(), accountID)
	if svcErr != nil {
		handleServiceError(c, svcErr)
		return
	}
	c.JSON(http.StatusOK, channels)
}

// RegisterSlackIntegrationRoutes registers Slack integration routes.
func RegisterSlackIntegrationRoutes(g *gin.RouterGroup, h *SlackIntegrationHandler) {
	g.POST("/slack", h.Create)
	g.PATCH("/slack", h.Update)
	g.PUT("/slack", h.Update)
	g.DELETE("/slack", h.Delete)

	slack := g.Group("/slack")
	{
		slack.POST("/", h.Create)
		slack.PATCH("/", h.Update)
		slack.PUT("/", h.Update)
		slack.DELETE("/", h.Delete)
		slack.GET("/list_all_channels", h.ListAllChannels)
	}
}

func (h *SlackIntegrationHandler) slackAppPayload(c *gin.Context, accountID uint, fallback []model.IntegrationHook) gin.H {
	hooks, err := h.svc.ListHooks(c.Request.Context(), accountID)
	if err != nil || len(hooks) == 0 {
		hooks = fallback
	}
	serializedHooks := make([]gin.H, 0, len(hooks))
	for _, hook := range hooks {
		serializedHooks = append(serializedHooks, serializeIntegrationHook(hook))
	}
	return gin.H{
		"id":                   "slack",
		"name":                 "Slack",
		"description":          "Connect Slack channels for real-time notifications",
		"short_description":    "Connect Slack channels for real-time notifications",
		"enabled":              len(serializedHooks) > 0,
		"hooks":                serializedHooks,
		"hook_type":            integrationAppHookType("slack"),
		"allow_multiple_hooks": integrationAppAllowsMultipleHooks("slack"),
		"settings_form_schema": integrationAppSettingsFormSchema("slack"),
		"visible_properties":   integrationAppVisibleProperties("slack"),
	}
}