package main

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

	"inou/lib"
)

type GenomeMatch struct {
	RSID        string   `json:"rsid"`
	Genotype    string   `json:"genotype"`
	Gene        string   `json:"gene,omitempty"`
	Matched     bool     `json:"matched"`
	Magnitude   *float64 `json:"magnitude,omitempty"`
	Repute      string   `json:"repute,omitempty"`
	Summary     string   `json:"summary,omitempty"`
	Category    string   `json:"category,omitempty"`
	Subcategory string   `json:"subcategory,omitempty"`
}

type GenomeResponse struct {
	Matches  []GenomeMatch `json:"matches"`
	Returned int           `json:"returned"`
	Total    int           `json:"total"`
}

func handleGenomeQuery(w http.ResponseWriter, r *http.Request) {
	ctx := getAccessContextOrFail(w, r)
	if ctx == nil {
		return
	}

	dossierID := r.URL.Query().Get("dossier")
	if dossierID == "" {
		http.Error(w, "missing dossier", http.StatusBadRequest)
		return
	}

	// RBAC enforced in lib layer - no checks here

	category := r.URL.Query().Get("category")
	search := r.URL.Query().Get("search")
	rsidsParam := r.URL.Query().Get("rsids")
	gene := r.URL.Query().Get("gene")
	includeHidden := r.URL.Query().Get("include_hidden") == "true"
	minMagStr := r.URL.Query().Get("min_magnitude")
	sortBy := r.URL.Query().Get("sort") // "magnitude" (default), "gene", "rsid"
	offsetStr := r.URL.Query().Get("offset")
	limitStr := r.URL.Query().Get("limit")

	var minMag float64
	if minMagStr != "" {
		minMag, _ = strconv.ParseFloat(minMagStr, 64)
	}

	offset := 0
	if offsetStr != "" {
		offset, _ = strconv.Atoi(offsetStr)
	}
	limit := 100 // default limit
	if limitStr != "" {
		limit, _ = strconv.Atoi(limitStr)
		if limit > 500 {
			limit = 500 // max limit
		}
	}

	var rsids []string
	if rsidsParam != "" {
		rsids = strings.Split(rsidsParam, ",")
	}

	var genes []string
	if gene != "" {
		for _, g := range strings.Split(gene, ",") {
			genes = append(genes, strings.TrimSpace(g))
		}
	}

	// Find extraction entry (RBAC enforced in lib)
	extraction, err := lib.GenomeGetExtraction(ctx, dossierID)
	if err != nil {
		w.Header().Set("Content-Type", "application/json")
		json.NewEncoder(w).Encode(map[string]string{"error": "no genome data for this dossier"})
		return
	}

	// Get tiers to query (RBAC enforced in lib)
	var tiers []lib.GenomeTier
	tierCategories := make(map[string]string) // tierID -> category name

	if category != "" {
		// Specific category requested
		tier, err := lib.GenomeGetTierByCategory(ctx, dossierID, extraction.EntryID, category)
		if err == nil {
			tiers = append(tiers, *tier)
			tierCategories[tier.TierID] = tier.Category
		}
	} else {
		// All tiers
		tiers, _ = lib.GenomeGetTiers(ctx, dossierID, extraction.EntryID)
		for _, t := range tiers {
			tierCategories[t.TierID] = t.Category
		}
	}

	if len(tiers) == 0 {
		w.Header().Set("Content-Type", "application/json")
		json.NewEncoder(w).Encode(GenomeResponse{Matches: []GenomeMatch{}, Returned: 0, Total: 0})
		return
	}

	// Get tier IDs
	tierIDs := make([]string, len(tiers))
	for i, t := range tiers {
		tierIDs[i] = t.TierID
	}

	// Query variants (RBAC enforced in lib)
	variants, err := lib.GenomeGetVariants(ctx, dossierID, tierIDs)
	if err != nil {
		w.Header().Set("Content-Type", "application/json")
		json.NewEncoder(w).Encode(GenomeResponse{Matches: []GenomeMatch{}, Returned: 0, Total: 0})
		return
	}

	// Filter and collect matches
	var matches []GenomeMatch
	total := 0

	for _, v := range variants {
		// Filter by rsids if specified
		if len(rsids) > 0 {
			found := false
			for _, r := range rsids {
				if r == v.RSID {
					found = true
					break
				}
			}
			if !found {
				continue
			}
		}

		// Filter by gene(s)
		if len(genes) > 0 {
			found := false
			for _, g := range genes {
				if strings.EqualFold(v.Gene, g) {
					found = true
					break
				}
			}
			if !found {
				continue
			}
		}

		// Filter by search
		if search != "" {
			searchLower := strings.ToLower(search)
			if !strings.Contains(strings.ToLower(v.Gene), searchLower) &&
				!strings.Contains(strings.ToLower(v.Summary), searchLower) &&
				!strings.Contains(strings.ToLower(v.Subcategory), searchLower) &&
				!strings.Contains(strings.ToLower(v.RSID), searchLower) {
				continue
			}
		}

		// Filter by magnitude
		if minMag > 0 && v.Magnitude < minMag {
			continue
		}
		if !includeHidden && v.Magnitude > 4.0 {
			continue
		}

		// Filter out "Bad" repute variants by default (scary/negative results)
		if !includeHidden && strings.EqualFold(v.Repute, "bad") {
			continue
		}

		total++
		// Apply offset and limit
		if total <= offset {
			continue
		}
		if len(matches) >= limit {
			continue
		}

		match := GenomeMatch{
			RSID:        v.RSID,
			Genotype:    v.Genotype,
			Gene:        v.Gene,
			Matched:     true,
			Category:    tierCategories[v.TierID],
			Subcategory: v.Subcategory,
		}
		if v.Magnitude > 0 {
			mag := v.Magnitude
			match.Magnitude = &mag
		}
		if v.Repute != "" {
			match.Repute = v.Repute
		}
		if v.Summary != "" {
			match.Summary = v.Summary
		}
		matches = append(matches, match)
	}

	// Sort results (default: magnitude descending)
	switch sortBy {
	case "gene":
		sort.Slice(matches, func(i, j int) bool {
			return matches[i].Gene < matches[j].Gene
		})
	case "rsid":
		sort.Slice(matches, func(i, j int) bool {
			return matches[i].RSID < matches[j].RSID
		})
	default: // "magnitude" or empty - sort by magnitude descending
		sort.Slice(matches, func(i, j int) bool {
			mi, mj := float64(0), float64(0)
			if matches[i].Magnitude != nil {
				mi = *matches[i].Magnitude
			}
			if matches[j].Magnitude != nil {
				mj = *matches[j].Magnitude
			}
			return mi > mj
		})
	}

	resp := GenomeResponse{
		Matches:  matches,
		Returned: len(matches),
		Total:    total,
	}

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