package admin

import (
	"net/http"
	"time"

	"github.com/gin-gonic/gin"
	"github.com/gothinkster/golang-gin-realworld-example-app/common"
	"github.com/gothinkster/golang-gin-realworld-example-app/models"
)

// ContractEntry is the contract address entry returned to the frontend.
type ContractEntry struct {
	Name    string `json:"name"`
	ChainID int    `json:"chain_id"`
	Address string `json:"address"`
}

// GetContracts is a public endpoint that returns all active contract addresses.
// Merges infrastructure contracts (system_contracts) and token contracts (assets).
func GetContracts(c *gin.Context) {
	db := common.GetDB()

	// Infrastructure contracts from system_contracts
	var sysContracts []models.SystemContract
	db.Where("is_active = ?", true).Find(&sysContracts)

	// Token contracts from assets
	var assets []models.Asset
	db.Where("is_active = ? AND contract_address != ''", true).Find(&assets)

	entries := make([]ContractEntry, 0, len(sysContracts)+len(assets))
	for _, sc := range sysContracts {
		if sc.Address != "" {
			entries = append(entries, ContractEntry{Name: sc.Name, ChainID: sc.ChainID, Address: sc.Address})
		}
	}
	for _, a := range assets {
		entries = append(entries, ContractEntry{Name: a.AssetCode, ChainID: a.ChainID, Address: a.ContractAddress})
	}

	c.JSON(http.StatusOK, gin.H{"contracts": entries})
}

// --- Admin CRUD for system_contracts ---

func ListSystemContracts(c *gin.Context) {
	db := common.GetDB()
	p := ParsePagination(c)

	query := db.Model(&models.SystemContract{})
	if v := c.Query("name"); v != "" {
		query = query.Where("name LIKE ?", "%"+v+"%")
	}
	if v := c.Query("chain_id"); v != "" {
		query = query.Where("chain_id = ?", v)
	}
	if v := c.Query("is_active"); v != "" {
		query = query.Where("is_active = ?", v == "true")
	}

	var total int64
	query.Count(&total)

	var items []models.SystemContract
	if err := query.Order("chain_id ASC, name ASC").Offset(p.Offset()).Limit(p.PageSize).Find(&items).Error; err != nil {
		Fail(c, http.StatusInternalServerError, "Failed to fetch system contracts")
		return
	}
	OKList(c, items, total)
}

func GetSystemContract(c *gin.Context) {
	db := common.GetDB()
	var item models.SystemContract
	if err := db.First(&item, c.Param("id")).Error; err != nil {
		Fail(c, http.StatusNotFound, "System contract not found")
		return
	}
	OK(c, item)
}

func CreateSystemContract(c *gin.Context) {
	db := common.GetDB()
	var item models.SystemContract
	if err := c.ShouldBindJSON(&item); err != nil {
		Fail(c, http.StatusBadRequest, err.Error())
		return
	}
	item.ID = 0
	now := time.Now()
	item.CreatedAt = now
	item.UpdatedAt = now
	if err := db.Create(&item).Error; err != nil {
		Fail(c, http.StatusInternalServerError, err.Error())
		return
	}
	LogOp(c, "create", "system_contract", "create_system_contract", &item.ID, item)
	OK(c, item)
}

func UpdateSystemContract(c *gin.Context) {
	db := common.GetDB()
	var existing models.SystemContract
	if err := db.First(&existing, c.Param("id")).Error; err != nil {
		Fail(c, http.StatusNotFound, "System contract not found")
		return
	}
	var item models.SystemContract
	if err := c.ShouldBindJSON(&item); err != nil {
		Fail(c, http.StatusBadRequest, err.Error())
		return
	}
	item.ID = existing.ID
	item.CreatedAt = existing.CreatedAt
	item.UpdatedAt = time.Now()
	if err := db.Save(&item).Error; err != nil {
		Fail(c, http.StatusInternalServerError, err.Error())
		return
	}
	LogOp(c, "update", "system_contract", "update_system_contract", &item.ID, item)
	OK(c, item)
}

func DeleteSystemContract(c *gin.Context) {
	db := common.GetDB()
	var item models.SystemContract
	if err := db.First(&item, c.Param("id")).Error; err != nil {
		Fail(c, http.StatusNotFound, "System contract not found")
		return
	}
	if err := db.Delete(&item).Error; err != nil {
		Fail(c, http.StatusInternalServerError, err.Error())
		return
	}
	LogOp(c, "delete", "system_contract", "delete_system_contract", &item.ID, nil)
	OK(c, gin.H{"message": "deleted"})
}