package api

import (
	"context"
	"net/http"
	"strconv"
	"strings"

	"github.com/ez-api/ez-api/internal/dto"
	"github.com/ez-api/ez-api/internal/model"
	"github.com/ez-api/ez-api/internal/service"
	"github.com/gin-gonic/gin"
	"github.com/redis/go-redis/v9"
	"gorm.io/gorm"
)

type Handler struct {
	db             *gorm.DB
	logDB          *gorm.DB
	sync           *service.SyncService
	logger         *service.LogWriter
	rdb            *redis.Client
	logWebhook     *service.LogWebhookService
	logPartitioner *service.LogPartitioner
	groupManager   *service.ProviderGroupManager
}

func NewHandler(db *gorm.DB, logDB *gorm.DB, sync *service.SyncService, logger *service.LogWriter, rdb *redis.Client, partitioner *service.LogPartitioner) *Handler {
	if logDB == nil {
		logDB = db
	}
	return &Handler{
		db:             db,
		logDB:          logDB,
		sync:           sync,
		logger:         logger,
		rdb:            rdb,
		logWebhook:     service.NewLogWebhookService(rdb),
		logPartitioner: partitioner,
		groupManager:   service.NewProviderGroupManager(),
	}
}

func (h *Handler) logDBConn() *gorm.DB {
	if h == nil || h.logDB == nil {
		return h.db
	}
	return h.logDB
}

func (h *Handler) logBaseQuery() *gorm.DB {
	return logBaseQuery(h.logDBConn(), h.logPartitioner)
}

// CreateKey is now handled by MasterHandler

// CreateModel godoc
// @Summary      Register a new model
// @Description  Register a supported model with its capabilities
// @Tags         admin
// @Accept       json
// @Produce      json
// @Security     AdminAuth
// @Param        model  body      dto.ModelDTO  true  "Model Info"
// @Success      201    {object}  model.Model
// @Failure      400    {object}  gin.H
// @Failure      500    {object}  gin.H
// @Router       /admin/models [post]
func (h *Handler) CreateModel(c *gin.Context) {
	var req dto.ModelDTO
	if err := c.ShouldBindJSON(&req); err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
		return
	}

	name := strings.TrimSpace(req.Name)
	if name == "" {
		c.JSON(http.StatusBadRequest, gin.H{"error": "name required"})
		return
	}
	kind := strings.ToLower(strings.TrimSpace(req.Kind))
	if kind == "" {
		kind = "chat"
	}
	switch kind {
	case "chat", "embedding", "rerank", "other":
	default:
		c.JSON(http.StatusBadRequest, gin.H{"error": "invalid kind"})
		return
	}

	modelReq := model.Model{
		Name:               name,
		Kind:               kind,
		ContextWindow:      req.ContextWindow,
		CostPerToken:       req.CostPerToken,
		SupportsVision:     req.SupportsVision,
		SupportsFunctions:  req.SupportsFunctions,
		SupportsToolChoice: req.SupportsToolChoice,
		SupportsFIM:        req.SupportsFIM,
		MaxOutputTokens:    req.MaxOutputTokens,
	}

	if err := h.db.Create(&modelReq).Error; err != nil {
		c.JSON(http.StatusInternalServerError, gin.H{"error": "Failed to create model", "details": err.Error()})
		return
	}

	if err := h.sync.SyncModel(&modelReq); err != nil {
		c.JSON(http.StatusInternalServerError, gin.H{"error": "Failed to sync model", "details": err.Error()})
		return
	}

	c.JSON(http.StatusCreated, modelReq)
}

// ListModels godoc
// @Summary      List all models
// @Description  Get a list of all registered models
// @Tags         admin
// @Produce      json
// @Security     AdminAuth
// @Param        page    query     int     false  "page (1-based)"
// @Param        limit   query     int     false  "limit (default 50, max 200)"
// @Param        search  query     string  false  "search by name/kind"
// @Success      200  {array}   model.Model
// @Failure      500  {object}  gin.H
// @Router       /admin/models [get]
func (h *Handler) ListModels(c *gin.Context) {
	var models []model.Model
	q := h.db.Model(&model.Model{}).Order("id desc")
	query := parseListQuery(c)
	q = applyListSearch(q, query.Search, "name", "kind")
	q = applyListPagination(q, query)
	if err := q.Find(&models).Error; err != nil {
		c.JSON(http.StatusInternalServerError, gin.H{"error": "Failed to list models", "details": err.Error()})
		return
	}
	c.JSON(http.StatusOK, models)
}

// UpdateModel godoc
// @Summary      Update a model
// @Description  Update an existing model's configuration
// @Tags         admin
// @Accept       json
// @Produce      json
// @Security     AdminAuth
// @Param        id     path      int           true  "Model ID"
// @Param        model  body      dto.ModelDTO  true  "Model Info"
// @Success      200    {object}  model.Model
// @Failure      400    {object}  gin.H
// @Failure      404    {object}  gin.H
// @Failure      500    {object}  gin.H
// @Router       /admin/models/{id} [put]
func (h *Handler) UpdateModel(c *gin.Context) {
	idParam := c.Param("id")
	id, err := strconv.Atoi(idParam)
	if err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": "invalid id"})
		return
	}

	var req dto.ModelDTO
	if err := c.ShouldBindJSON(&req); err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
		return
	}

	var existing model.Model
	if err := h.db.First(&existing, id).Error; err != nil {
		c.JSON(http.StatusNotFound, gin.H{"error": "model not found"})
		return
	}

	name := strings.TrimSpace(req.Name)
	if name == "" {
		c.JSON(http.StatusBadRequest, gin.H{"error": "name required"})
		return
	}
	kind := strings.ToLower(strings.TrimSpace(req.Kind))
	if kind == "" {
		kind = strings.ToLower(strings.TrimSpace(existing.Kind))
	}
	if kind == "" {
		kind = "chat"
	}
	switch kind {
	case "chat", "embedding", "rerank", "other":
	default:
		c.JSON(http.StatusBadRequest, gin.H{"error": "invalid kind"})
		return
	}

	existing.Name = name
	existing.Kind = kind
	existing.ContextWindow = req.ContextWindow
	existing.CostPerToken = req.CostPerToken
	existing.SupportsVision = req.SupportsVision
	existing.SupportsFunctions = req.SupportsFunctions
	existing.SupportsToolChoice = req.SupportsToolChoice
	existing.SupportsFIM = req.SupportsFIM
	existing.MaxOutputTokens = req.MaxOutputTokens

	if err := h.db.Save(&existing).Error; err != nil {
		c.JSON(http.StatusInternalServerError, gin.H{"error": "Failed to update model", "details": err.Error()})
		return
	}

	if err := h.sync.SyncModel(&existing); err != nil {
		c.JSON(http.StatusInternalServerError, gin.H{"error": "Failed to sync model", "details": err.Error()})
		return
	}

	c.JSON(http.StatusOK, existing)
}

// DeleteModel godoc
// @Summary      Delete a model
// @Description  Delete a model by id
// @Tags         admin
// @Produce      json
// @Security     AdminAuth
// @Param        id   path      int  true  "Model ID"
// @Success      200  {object}  gin.H
// @Failure      400  {object}  gin.H
// @Failure      404  {object}  gin.H
// @Failure      500  {object}  gin.H
// @Router       /admin/models/{id} [delete]
func (h *Handler) DeleteModel(c *gin.Context) {
	idParam := c.Param("id")
	id, err := strconv.Atoi(idParam)
	if err != nil || id <= 0 {
		c.JSON(http.StatusBadRequest, gin.H{"error": "invalid id"})
		return
	}

	var existing model.Model
	if err := h.db.First(&existing, id).Error; err != nil {
		c.JSON(http.StatusNotFound, gin.H{"error": "model not found"})
		return
	}

	if err := h.db.Delete(&existing).Error; err != nil {
		c.JSON(http.StatusInternalServerError, gin.H{"error": "Failed to delete model", "details": err.Error()})
		return
	}

	if err := h.sync.SyncModelDelete(&existing); err != nil {
		c.JSON(http.StatusInternalServerError, gin.H{"error": "Failed to sync model delete", "details": err.Error()})
		return
	}

	c.JSON(http.StatusOK, gin.H{"status": "deleted"})
}

// SyncSnapshot godoc
// @Summary      Force sync snapshot
// @Description  Force full synchronization of DB state to Redis
// @Tags         admin
// @Produce      json
// @Security     AdminAuth
// @Success      200  {object}  gin.H
// @Failure      500  {object}  gin.H
// @Router       /admin/sync/snapshot [post]
func (h *Handler) SyncSnapshot(c *gin.Context) {
	if err := h.sync.SyncAll(h.db); err != nil {
		c.JSON(http.StatusInternalServerError, gin.H{"error": "Failed to sync snapshots", "details": err.Error()})
		return
	}
	c.JSON(http.StatusOK, gin.H{"status": "synced"})
}

// IngestLog accepts log records from data plane or other services.
// @Summary      Ingest logs
// @Description  Internal endpoint for ingesting logs from Balancer
// @Tags         system
// @Accept       json
// @Produce      json
// @Param        log  body      model.LogRecord  true  "Log Record"
// @Success      202  {object}  gin.H
// @Failure      400  {object}  gin.H
// @Router       /logs [post]
func (h *Handler) IngestLog(c *gin.Context) {
	var rec model.LogRecord
	if err := c.ShouldBindJSON(&rec); err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
		return
	}

	if !h.logRequestBodyEnabled(c.Request.Context()) {
		rec.RequestBody = ""
	}

	// By default, only metadata is expected; payload fields may be empty.
	if h.logger != nil {
		h.logger.Write(rec)
	}
	if h.logWebhook != nil {
		recCopy := rec
		go h.logWebhook.NotifyIfNeeded(context.Background(), recCopy)
	}
	c.JSON(http.StatusAccepted, gin.H{"status": "queued"})
}

func (h *Handler) logRequestBodyEnabled(ctx context.Context) bool {
	if h == nil || h.rdb == nil {
		return true
	}
	raw, err := h.rdb.HGet(ctx, featuresKey, logRequestBodyFeatureKey).Result()
	if err == redis.Nil || strings.TrimSpace(raw) == "" {
		return true
	}
	if err != nil {
		return true
	}
	return strings.EqualFold(raw, "true") || strings.EqualFold(raw, "1")
}