package api

import (
	"encoding/json"
	"errors"
	"net/http"
	"strconv"

	"github.com/gin-gonic/gin"
	"github.com/openteam/server/internal/pkg/resp"
	"github.com/openteam/server/internal/store"
	"gorm.io/gorm"
)

// AdminModels GET /api/v1/admin/models — 模型列表（含价格、渠道绑定、定价/禁止状态）。
func (h *Handler) AdminModels(c *gin.Context) {
	var ms []store.Model
	if err := h.a.DB.Order("sort ASC, id ASC").Find(&ms).Error; err != nil {
		resp.Fail(c, http.StatusInternalServerError, "failed to load models")
		return
	}

	// 全局模型限制策略
	allow, deny := h.modelPolicyConfig()

	out := make([]gin.H, 0, len(ms))
	for _, m := range ms {
		var bindings []store.ChannelModelBinding
		h.a.DB.Preload("Channel").Where("model_id = ?", m.ID).Find(&bindings)
		chs := make([]gin.H, 0, len(bindings))
		for _, b := range bindings {
			chs = append(chs, gin.H{
				"id": b.ID, "channel_id": b.ChannelID, "channel_name": b.Channel.Name,
				"upstream_model": b.UpstreamModel, "weight": b.Weight,
			})
		}
		used := len(bindings) > 0
		needsPricing := used && m.InputPrice == 0 && m.OutputPrice == 0 && m.CacheReadPrice == 0
		denied := containsStr(deny, m.Name) || (len(allow) > 0 && !containsStr(allow, m.Name))
		out = append(out, gin.H{
			"id": m.ID, "name": m.Name, "display_name": m.DisplayName,
			"input_price": m.InputPrice, "output_price": m.OutputPrice, "cache_read_price": m.CacheReadPrice,
			"enabled": m.Enabled, "sort": m.Sort, "channels": chs,
			"used": used, "needs_pricing": needsPricing, "denied": denied,
		})
	}

	// 渠道选中但目录中缺失的模型（孤儿绑定：渠道绑定指向已被删除的模型）
	var orphans []struct {
		ChannelName   string
		UpstreamModel string
		ModelID       uint64
	}
	h.a.DB.Raw(`SELECT c.name as channel_name, b.model_id, b.upstream_model
		FROM channel_model_bindings b
		LEFT JOIN models m ON m.id = b.model_id
		LEFT JOIN channels c ON c.id = b.channel_id
		WHERE m.id IS NULL`).Scan(&orphans)
	missing := make([]gin.H, 0, len(orphans))
	for _, o := range orphans {
		missing = append(missing, gin.H{
			"channel": o.ChannelName, "model_id": o.ModelID, "upstream_model": o.UpstreamModel,
		})
	}

	// 在用但未定价的模型数（渠道已提供、需定价）
	unpriced := 0
	{
		var usedBindings []struct {
			ModelID uint64
		}
		h.a.DB.Model(&store.ChannelModelBinding{}).Distinct("model_id").Scan(&usedBindings)
		usedIDs := map[uint64]bool{}
		for _, u := range usedBindings {
			usedIDs[u.ModelID] = true
		}
		for _, m := range ms {
			if usedIDs[m.ID] && m.InputPrice == 0 && m.OutputPrice == 0 && m.CacheReadPrice == 0 {
				unpriced++
			}
		}
	}

	resp.OK(c, gin.H{
		"items": out,
		"summary": gin.H{
			"total":        len(ms),
			"unpriced":     unpriced,
			"missing":      missing,
			"denied_count": len(deny),
		},
	})
}

// modelPolicyConfig 读取全局模型允许/禁止列表。
func (h *Handler) modelPolicyConfig() (allow, deny []string) {
	var raw string
	h.a.DB.Model(&store.SystemConfig{}).Where("key = ?", "model_allowlist").Pluck("value", &raw)
	_ = json.Unmarshal([]byte(raw), &allow)
	raw = ""
	h.a.DB.Model(&store.SystemConfig{}).Where("key = ?", "model_denylist").Pluck("value", &raw)
	_ = json.Unmarshal([]byte(raw), &deny)
	return
}

func containsStr(list []string, s string) bool {
	for _, v := range list {
		if v == s {
			return true
		}
	}
	return false
}

// AdminCreateModel POST /api/v1/admin/models
func (h *Handler) AdminCreateModel(c *gin.Context) {
	var req struct {
		Name           string  `json:"name" binding:"required,min=1,max=128"`
		DisplayName    string  `json:"display_name"`
		InputPrice     float64 `json:"input_price"`
		OutputPrice    float64 `json:"output_price"`
		CacheReadPrice float64 `json:"cache_read_price"`
		Enabled        *bool   `json:"enabled"`
	}
	if err := c.ShouldBindJSON(&req); err != nil {
		resp.Fail(c, http.StatusBadRequest, "invalid input: "+err.Error())
		return
	}
	m := store.Model{
		Name: req.Name, DisplayName: req.DisplayName,
		InputPrice: req.InputPrice, OutputPrice: req.OutputPrice, CacheReadPrice: req.CacheReadPrice,
		Enabled: boolOr(req.Enabled, true),
	}
	if m.DisplayName == "" {
		m.DisplayName = m.Name
	}
	if err := h.a.DB.Create(&m).Error; err != nil {
		resp.Fail(c, http.StatusConflict, "failed to create model (name may already exist)")
		return
	}
	resp.Created(c, gin.H{"id": m.ID, "name": m.Name})
}

// AdminUpdateModel PUT /api/v1/admin/models/:id — 价格/展示名/启停/排序。
func (h *Handler) AdminUpdateModel(c *gin.Context) {
	id, err := strconv.ParseUint(c.Param("id"), 10, 64)
	if err != nil {
		resp.Fail(c, http.StatusBadRequest, "invalid model id")
		return
	}
	var req struct {
		DisplayName    *string  `json:"display_name"`
		InputPrice     *float64 `json:"input_price"`
		OutputPrice    *float64 `json:"output_price"`
		CacheReadPrice *float64 `json:"cache_read_price"`
		Enabled        *bool    `json:"enabled"`
		Sort           *int     `json:"sort"`
	}
	if err := c.ShouldBindJSON(&req); err != nil {
		resp.Fail(c, http.StatusBadRequest, "invalid input")
		return
	}
	var m store.Model
	if err := h.a.DB.First(&m, id).Error; err != nil {
		resp.Fail(c, http.StatusNotFound, "model not found")
		return
	}
	updates := map[string]any{}
	if req.DisplayName != nil {
		updates["display_name"] = *req.DisplayName
	}
	if req.InputPrice != nil {
		updates["input_price"] = *req.InputPrice
	}
	if req.OutputPrice != nil {
		updates["output_price"] = *req.OutputPrice
	}
	if req.CacheReadPrice != nil {
		updates["cache_read_price"] = *req.CacheReadPrice
	}
	if req.Enabled != nil {
		updates["enabled"] = *req.Enabled
	}
	if req.Sort != nil {
		updates["sort"] = *req.Sort
	}
	if len(updates) > 0 {
		if err := h.a.DB.Model(&m).Updates(updates).Error; err != nil {
			resp.Fail(c, http.StatusInternalServerError, "failed to update model")
			return
		}
	}
	resp.OK(c, gin.H{"ok": true})
}

// AdminDeleteModel DELETE /api/v1/admin/models/:id
func (h *Handler) AdminDeleteModel(c *gin.Context) {
	id, err := strconv.ParseUint(c.Param("id"), 10, 64)
	if err != nil {
		resp.Fail(c, http.StatusBadRequest, "invalid model id")
		return
	}
	res := h.a.DB.Delete(&store.Model{}, id)
	if res.Error != nil {
		resp.Fail(c, http.StatusInternalServerError, "failed to delete model")
		return
	}
	if res.RowsAffected == 0 {
		resp.Fail(c, http.StatusNotFound, "model not found")
		return
	}
	h.a.DB.Where("model_id = ?", id).Delete(&store.ChannelModelBinding{})
	resp.OK(c, gin.H{"ok": true})
}

// AdminDeleteUnusedModels DELETE /api/v1/admin/models/unused — 一键清除未绑定任何渠道的模型。
// 这些通常是渠道抽屉里选中过、后来又取消绑定留下的目录条目，客户端无法调用。
func (h *Handler) AdminDeleteUnusedModels(c *gin.Context) {
	var orphans []store.Model
	if err := h.a.DB.Where("id NOT IN (SELECT DISTINCT model_id FROM channel_model_bindings)").Find(&orphans).Error; err != nil {
		resp.Fail(c, http.StatusInternalServerError, "failed to load models")
		return
	}
	names := make([]string, 0, len(orphans))
	ids := make([]uint64, 0, len(orphans))
	for _, m := range orphans {
		names = append(names, m.Name)
		ids = append(ids, m.ID)
	}
	if len(ids) > 0 {
		if err := h.a.DB.Delete(&store.Model{}, ids).Error; err != nil {
			resp.Fail(c, http.StatusInternalServerError, "failed to delete models")
			return
		}
	}
	resp.OK(c, gin.H{"deleted": names, "count": len(names)})
}

// AdminCreateModelBinding POST /api/v1/admin/models/:id/bindings
func (h *Handler) AdminCreateModelBinding(c *gin.Context) {
	modelID, err := strconv.ParseUint(c.Param("id"), 10, 64)
	if err != nil {
		resp.Fail(c, http.StatusBadRequest, "invalid model id")
		return
	}
	var req struct {
		ChannelID     uint64 `json:"channel_id" binding:"required"`
		UpstreamModel string `json:"upstream_model" binding:"required"`
		Weight        *int   `json:"weight"`
	}
	if err := c.ShouldBindJSON(&req); err != nil {
		resp.Fail(c, http.StatusBadRequest, "invalid input: channel_id and upstream_model required")
		return
	}
	var m store.Model
	if err := h.a.DB.First(&m, modelID).Error; err != nil {
		resp.Fail(c, http.StatusNotFound, "model not found")
		return
	}
	var ch store.Channel
	if err := h.a.DB.First(&ch, req.ChannelID).Error; err != nil {
		resp.Fail(c, http.StatusNotFound, "channel not found")
		return
	}
	b := store.ChannelModelBinding{
		ChannelID: req.ChannelID, ModelID: modelID,
		UpstreamModel: req.UpstreamModel, Weight: intOr(req.Weight, 1),
	}
	if err := h.a.DB.Create(&b).Error; err != nil {
		resp.Fail(c, http.StatusConflict, "binding may already exist")
		return
	}
	resp.Created(c, gin.H{"id": b.ID})
}

// AdminDeleteModelBinding DELETE /api/v1/admin/models/:id/bindings/:bid
func (h *Handler) AdminDeleteModelBinding(c *gin.Context) {
	bid, err := strconv.ParseUint(c.Param("bid"), 10, 64)
	if err != nil {
		resp.Fail(c, http.StatusBadRequest, "invalid binding id")
		return
	}
	res := h.a.DB.Delete(&store.ChannelModelBinding{}, bid)
	if res.Error != nil {
		resp.Fail(c, http.StatusInternalServerError, "failed to delete binding")
		return
	}
	if res.RowsAffected == 0 {
		resp.Fail(c, http.StatusNotFound, "binding not found")
		return
	}
	resp.OK(c, gin.H{"ok": true})
}

var _ = errors.Is
var _ = gorm.ErrRecordNotFound