package api

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

	fleetai "crypto-miner-server/internal/ai"
	"crypto-miner-server/internal/db"
)

// SeerHandler serves read-only Seer stream and notes APIs.
type SeerHandler struct {
	db interface {
		ListSeerEvents(limit int) ([]db.SeerEventRecord, error)
		ListSeerNotes(limit int) ([]db.SeerNoteRecord, error)
		InsertSeerNote(agentID, note, source string) error
	}
}

func NewSeerHandler(database interface {
	ListSeerEvents(limit int) ([]db.SeerEventRecord, error)
	ListSeerNotes(limit int) ([]db.SeerNoteRecord, error)
	InsertSeerNote(agentID, note, source string) error
}) *SeerHandler {
	return &SeerHandler{db: database}
}

// GET /api/v1/seer/stream — LLM event stream + persisted notes snapshot.
func (h *SeerHandler) GetStream(w http.ResponseWriter, r *http.Request) {
	limit := parseLimit(r, 100)
	if h.db == nil {
		writeJSON(w, map[string]interface{}{
			"events": []db.SeerEventRecord{},
			"notes":  []db.SeerNoteRecord{},
		})
		return
	}
	events, err := h.db.ListSeerEvents(limit)
	if err != nil {
		http.Error(w, err.Error(), http.StatusInternalServerError)
		return
	}
	notes, err := h.db.ListSeerNotes(limit)
	if err != nil {
		http.Error(w, err.Error(), http.StatusInternalServerError)
		return
	}
	if events == nil {
		events = []db.SeerEventRecord{}
	}
	if notes == nil {
		notes = []db.SeerNoteRecord{}
	}
	writeJSON(w, map[string]interface{}{"events": events, "notes": notes})
}

// POST /api/v1/seer/stream — append a note (read-only UI; API for scheduler/tests).
func (h *SeerHandler) PostStream(w http.ResponseWriter, r *http.Request) {
	h.PostNote(w, r)
}

func (h *SeerHandler) GetNotes(w http.ResponseWriter, r *http.Request) {
	if h.db == nil {
		writeJSON(w, []db.SeerNoteRecord{})
		return
	}
	limit := parseLimit(r, 100)
	rows, err := h.db.ListSeerNotes(limit)
	if err != nil {
		http.Error(w, err.Error(), http.StatusInternalServerError)
		return
	}
	if rows == nil {
		rows = []db.SeerNoteRecord{}
	}
	writeJSON(w, rows)
}

func (h *SeerHandler) PostNote(w http.ResponseWriter, r *http.Request) {
	if h.db == nil {
		http.Error(w, "database unavailable", http.StatusServiceUnavailable)
		return
	}
	var body struct {
		AgentID string `json:"agent_id"`
		Note    string `json:"note"`
		Source  string `json:"source"`
	}
	if err := json.NewDecoder(r.Body).Decode(&body); err != nil {
		http.Error(w, "invalid JSON", http.StatusBadRequest)
		return
	}
	note := strings.TrimSpace(body.Note)
	if note == "" {
		http.Error(w, "note required", http.StatusBadRequest)
		return
	}
	source := strings.TrimSpace(body.Source)
	if source == "" {
		source = "manual"
	}
	if err := h.db.InsertSeerNote(body.AgentID, note, source); err != nil {
		http.Error(w, err.Error(), http.StatusInternalServerError)
		return
	}
	writeJSON(w, map[string]bool{"ok": true})
}

// GET /api/v1/seer/tools — documented AI tool-call endpoints.
func (h *SeerHandler) GetTools(w http.ResponseWriter, _ *http.Request) {
	writeJSON(w, map[string]interface{}{
		"tools": []map[string]string{
			{"name": "spread_route", "method": "POST", "path": "/api/v1/seer/tools/spread_route",
				"description": "BGP-style minimum-clearance spread routing"},
			{"name": "graft_strain", "method": "POST", "path": "/api/v1/seer/tools/graft_strain",
				"description": "Clone winning spread strain onto sibling subnet"},
			{"name": "fork_onion", "method": "POST", "path": "/api/v1/seer/tools/fork_onion",
				"description": "Split LOTL tier chain for A/B recovery"},
		},
		"catalog": fleetai.SeerToolCatalog,
	})
}

func (h *SeerHandler) ToolSpreadRoute(w http.ResponseWriter, r *http.Request) {
	seerToolStub(w, r, "spread_route")
}

func (h *SeerHandler) ToolGraftStrain(w http.ResponseWriter, r *http.Request) {
	seerToolStub(w, r, "graft_strain")
}

func (h *SeerHandler) ToolForkOnion(w http.ResponseWriter, r *http.Request) {
	seerToolStub(w, r, "fork_onion")
}

func seerToolStub(w http.ResponseWriter, r *http.Request, tool string) {
	var body json.RawMessage
	if r.Body != nil {
		_ = json.NewDecoder(r.Body).Decode(&body)
	}
	if body == nil {
		body = json.RawMessage(`{}`)
	}
	writeJSON(w, map[string]interface{}{
		"ok": true, "stub": true, "tool": tool, "received": json.RawMessage(body),
	})
}

func parseLimit(r *http.Request, fallback int) int {
	limit := fallback
	if raw := r.URL.Query().Get("limit"); raw != "" {
		if n, err := strconv.Atoi(raw); err == nil && n > 0 {
			limit = n
		}
	}
	return limit
}