package main

import (
	"database/sql"
	"encoding/json"
	"fmt"
	"log"
	"net/http"
	"net/url"
	"strconv"
	"strings"
	"time"
)

func adminAuth(token string, next http.Handler) http.Handler {
	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		if r.Header.Get("Authorization") == "Bearer "+token {
			next.ServeHTTP(w, r)
			return
		}
		w.Header().Set("Content-Type", "application/json")
		w.WriteHeader(http.StatusUnauthorized)
		w.Write([]byte(`{"error":"unauthorized"}`))
	})
}

func handleAdminPage() http.HandlerFunc {
	return func(w http.ResponseWriter, r *http.Request) {
		http.ServeFile(w, r, "static/admin.html")
	}
}

type adminRepeatersResponse struct {
	Repeaters []Repeater `json:"repeaters"`
	Total     int        `json:"total"`
	Page      int        `json:"page"`
	PerPage   int        `json:"per_page"`
}

func handleAdminUpdateRepeater(db *sql.DB) http.HandlerFunc {
	return func(w http.ResponseWriter, r *http.Request) {
		if r.Method != http.MethodPut {
			http.Error(w, `{"error":"method not allowed"}`, http.StatusMethodNotAllowed)
			return
		}

		var rpt Repeater
		if err := json.NewDecoder(r.Body).Decode(&rpt); err != nil {
			http.Error(w, `{"error":"invalid request body"}`, http.StatusBadRequest)
			return
		}
		if rpt.ID <= 0 {
			http.Error(w, `{"error":"missing repeater id"}`, http.StatusBadRequest)
			return
		}

		oldRpt, fetchErr := queryRepeaterByID(db, rpt.ID)
		if fetchErr != nil {
			log.Printf("changelog: could not fetch old repeater %d for diff: %v", rpt.ID, fetchErr)
		}

		if err := updateRepeater(db, rpt); err != nil {
			http.Error(w, `{"error":"update failed"}`, http.StatusInternalServerError)
			return
		}

		var oldVals, newVals map[string]interface{}
		if oldRpt != nil {
			oldVals, newVals = diffRepeater(*oldRpt, rpt)
		}
		if oldVals != nil || oldRpt == nil {
			insertChangelog(db, ChangelogEntry{
				RepeaterID:  rpt.ID,
				Callsign:    rpt.Callsign,
				Source:      "admin",
				Action:      "update",
				Description: "Admin updated repeater",
				OldValues:   oldVals,
				NewValues:   newVals,
			})
		}

		w.Header().Set("Content-Type", "application/json")
		w.Write([]byte(`{"ok":true}`))
	}
}

func handleBMDevice() http.HandlerFunc {
	client := &http.Client{Timeout: 15 * time.Second}
	return func(w http.ResponseWriter, r *http.Request) {
		if r.Method != http.MethodGet {
			http.Error(w, `{"error":"method not allowed"}`, http.StatusMethodNotAllowed)
			return
		}
		id := r.URL.Query().Get("id")
		if id == "" {
			http.Error(w, `{"error":"missing id"}`, http.StatusBadRequest)
			return
		}
		if _, err := strconv.Atoi(id); err != nil {
			http.Error(w, `{"error":"invalid id"}`, http.StatusBadRequest)
			return
		}

		url := fmt.Sprintf("https://api.brandmeister.network/v2/device/%s", id)
		resp, err := client.Get(url)
		if err != nil {
			log.Printf("BM device proxy: HTTP error for %s: %v", id, err)
			http.Error(w, `{"error":"upstream request failed"}`, http.StatusBadGateway)
			return
		}
		defer resp.Body.Close()

		if resp.StatusCode == http.StatusNotFound {
			http.Error(w, `{"error":"device not found on BrandMeister"}`, http.StatusNotFound)
			return
		}
		if resp.StatusCode != http.StatusOK {
			log.Printf("BM device proxy: HTTP %d for %s", resp.StatusCode, id)
			http.Error(w, `{"error":"upstream error"}`, http.StatusBadGateway)
			return
		}

		var device bmDeviceResponse
		if err := json.NewDecoder(resp.Body).Decode(&device); err != nil {
			log.Printf("BM device proxy: decode error for %s: %v", id, err)
			http.Error(w, `{"error":"decode error"}`, http.StatusBadGateway)
			return
		}

		desc := device.Description
		if device.PriorityDescription != "" {
			if desc != "" {
				desc = device.PriorityDescription + "\n" + desc
			} else {
				desc = device.PriorityDescription
			}
		}
		desc = stripHTML(desc)

		w.Header().Set("Content-Type", "application/json")
		json.NewEncoder(w).Encode(map[string]interface{}{
			"last_seen":      device.LastSeen,
			"status":         device.Status,
			"status_text":    device.StatusText,
			"hardware":       device.Hardware,
			"firmware":       device.Firmware,
			"pep":            device.Pep,
			"agl":            device.Agl,
			"website":        device.Website,
			"description":    desc,
			"tx":             device.Tx,
			"rx":             device.Rx,
			"last_known_master": device.LastKnownMaster,
		})
	}
}

func handleAdminRepeaters(db *sql.DB) http.HandlerFunc {
	return func(w http.ResponseWriter, r *http.Request) {
		if r.Method != http.MethodGet {
			http.Error(w, `{"error":"method not allowed"}`, http.StatusMethodNotAllowed)
			return
		}

		q := r.URL.Query()
		page := 1
		if v := q.Get("page"); v != "" {
			if p, err := strconv.Atoi(v); err == nil && p > 0 {
				page = p
			}
		}

		perPage := 50
		if v := q.Get("per_page"); v != "" {
			if p, err := strconv.Atoi(v); err == nil && p > 0 {
				perPage = p
			}
		}
		if perPage > 200 {
			perPage = 200
		}

		search := strings.TrimSpace(q.Get("q"))
		filters, filterMode := parseAdminFilters(q)

		repeaters, total, err := queryAdminRepeaters(db, search, page, perPage, filters, filterMode)
		if err != nil {
			http.Error(w, `{"error":"database query failed"}`, http.StatusInternalServerError)
			return
		}

		w.Header().Set("Content-Type", "application/json")
		json.NewEncoder(w).Encode(adminRepeatersResponse{
			Repeaters: repeaters,
			Total:     total,
			Page:      page,
			PerPage:   perPage,
		})
	}
}

func handleAdminSaveBMData(db *sql.DB) http.HandlerFunc {
	return func(w http.ResponseWriter, r *http.Request) {
		if r.Method != http.MethodPut {
			http.Error(w, `{"error":"method not allowed"}`, http.StatusMethodNotAllowed)
			return
		}

		var payload struct {
			ID              int    `json:"id"`
			LastSeen        string `json:"last_seen"`
			BmStatus        *int   `json:"bm_status"`
			BmStatusText    string `json:"bm_status_text"`
			Hardware        string `json:"hardware"`
			Firmware        string `json:"firmware"`
			Pep             int    `json:"pep"`
			Agl             int    `json:"agl"`
			Website         string `json:"website"`
			Description     string `json:"description"`
			LastKnownMaster int    `json:"last_known_master"`
		}
		if err := json.NewDecoder(r.Body).Decode(&payload); err != nil {
			http.Error(w, `{"error":"invalid request body"}`, http.StatusBadRequest)
			return
		}
		if payload.ID <= 0 {
			http.Error(w, `{"error":"missing id"}`, http.StatusBadRequest)
			return
		}

		var lastSeen *time.Time
		if payload.LastSeen != "" {
			if t, err := time.Parse("2006-01-02 15:04:05", payload.LastSeen); err == nil {
				lastSeen = &t
			}
		}

		_, err := db.Exec(`UPDATE repeaters SET
			last_seen=$1, bm_status=$2, bm_status_text=$3,
			hardware=$4, firmware=$5, pep=$6, agl=$7,
			website=$8, description=$9, last_polled=NOW()
			WHERE id=$10`,
			lastSeen, payload.BmStatus, payload.BmStatusText,
			payload.Hardware, payload.Firmware, payload.Pep, payload.Agl,
			payload.Website, payload.Description, payload.ID)
		if err != nil {
			log.Printf("Admin save BM data: update failed for %d: %v", payload.ID, err)
			http.Error(w, `{"error":"update failed"}`, http.StatusInternalServerError)
			return
		}

		insertChangelog(db, ChangelogEntry{
			RepeaterID:  payload.ID,
			Source:      "admin",
			Action:      "update_bm_data",
			Description: "Admin saved BrandMeister device data",
			NewValues: map[string]interface{}{
				"last_seen":      payload.LastSeen,
				"bm_status":      payload.BmStatus,
				"bm_status_text": payload.BmStatusText,
				"hardware":       payload.Hardware,
				"firmware":       payload.Firmware,
				"pep":            payload.Pep,
				"agl":            payload.Agl,
				"website":        payload.Website,
				"description":    payload.Description,
			},
		})

		// Add Brandmeister tag if valid master server
		if payload.LastKnownMaster != 0 && payload.LastKnownMaster != 9999 {
			if _, tagErr := db.Exec(`UPDATE repeaters SET networks = array_append(networks, 'Brandmeister')
				WHERE id = $1 AND NOT networks @> ARRAY['Brandmeister']`, payload.ID); tagErr == nil {
				insertChangelog(db, ChangelogEntry{
					RepeaterID:  payload.ID,
					Source:      "admin",
					Action:      "add_bm_tag",
					Description: fmt.Sprintf("Added Brandmeister network tag (master=%d)", payload.LastKnownMaster),
				})
			}
		}

		w.Header().Set("Content-Type", "application/json")
		w.Write([]byte(`{"ok":true}`))
	}
}

func handleAdminRemoveBMTag(db *sql.DB) http.HandlerFunc {
	return func(w http.ResponseWriter, r *http.Request) {
		if r.Method != http.MethodPut {
			http.Error(w, `{"error":"method not allowed"}`, http.StatusMethodNotAllowed)
			return
		}

		var payload struct {
			ID int `json:"id"`
		}
		if err := json.NewDecoder(r.Body).Decode(&payload); err != nil {
			http.Error(w, `{"error":"invalid request body"}`, http.StatusBadRequest)
			return
		}
		if payload.ID <= 0 {
			http.Error(w, `{"error":"missing id"}`, http.StatusBadRequest)
			return
		}

		_, err := db.Exec(`UPDATE repeaters SET networks = array_remove(networks, 'Brandmeister'), last_polled=NOW() WHERE id = $1`, payload.ID)
		if err != nil {
			http.Error(w, `{"error":"update failed"}`, http.StatusInternalServerError)
			return
		}

		insertChangelog(db, ChangelogEntry{
			RepeaterID:  payload.ID,
			Source:      "admin",
			Action:      "remove_bm_tag",
			Description: "Admin removed Brandmeister network tag",
		})

		w.Header().Set("Content-Type", "application/json")
		w.Write([]byte(`{"ok":true}`))
	}
}

func handleAdminChangelog(db *sql.DB) http.HandlerFunc {
	return func(w http.ResponseWriter, r *http.Request) {
		if r.Method != http.MethodGet {
			http.Error(w, `{"error":"method not allowed"}`, http.StatusMethodNotAllowed)
			return
		}

		idStr := r.URL.Query().Get("id")
		if idStr == "" {
			http.Error(w, `{"error":"missing id"}`, http.StatusBadRequest)
			return
		}
		id, err := strconv.Atoi(idStr)
		if err != nil || id <= 0 {
			http.Error(w, `{"error":"invalid id"}`, http.StatusBadRequest)
			return
		}

		rows, err := db.Query(
			`SELECT created_at, source, action, description, old_values, new_values
			 FROM changelog WHERE repeater_id = $1
			 ORDER BY created_at DESC LIMIT 100`, id)
		if err != nil {
			log.Printf("Admin changelog: query failed for %d: %v", id, err)
			http.Error(w, `{"error":"query failed"}`, http.StatusInternalServerError)
			return
		}
		defer rows.Close()

		type entry struct {
			CreatedAt   string           `json:"created_at"`
			Source      string           `json:"source"`
			Action      string           `json:"action"`
			Description string           `json:"description"`
			OldValues   *json.RawMessage `json:"old_values"`
			NewValues   *json.RawMessage `json:"new_values"`
		}

		var entries []entry
		for rows.Next() {
			var e entry
			var createdAt time.Time
			var oldJSON, newJSON *string
			if err := rows.Scan(&createdAt, &e.Source, &e.Action, &e.Description, &oldJSON, &newJSON); err != nil {
				continue
			}
			e.CreatedAt = createdAt.Format("2006-01-02 15:04:05")
			if oldJSON != nil {
				raw := json.RawMessage(*oldJSON)
				e.OldValues = &raw
			}
			if newJSON != nil {
				raw := json.RawMessage(*newJSON)
				e.NewValues = &raw
			}
			entries = append(entries, e)
		}
		if entries == nil {
			entries = []entry{}
		}

		w.Header().Set("Content-Type", "application/json")
		json.NewEncoder(w).Encode(entries)
	}
}

func parseAdminFilters(q url.Values) ([]Filter, string) {
	mode := q.Get("filter_mode")
	if mode != "or" {
		mode = "and"
	}
	raw := q.Get("filters")
	if raw == "" {
		return nil, mode
	}
	var filters []Filter
	json.Unmarshal([]byte(raw), &filters)
	return filters, mode
}