"use client";

import { useState, useMemo, useEffect } from "react";
import Modal from "./Modal";
import { getModelsByProviderId, PROVIDER_ID_TO_ALIAS } from "@/shared/constants/models";
import { OAUTH_PROVIDERS, APIKEY_PROVIDERS } from "@/shared/constants/providers";

// Provider order: OAuth first, then API Key (matches dashboard/providers)
const PROVIDER_ORDER = [
  ...Object.keys(OAUTH_PROVIDERS),
  ...Object.keys(APIKEY_PROVIDERS),
];

export default function ModelSelectModal({
  isOpen,
  onClose,
  onSelect,
  selectedModel,
  activeProviders = [],
  title = "Select Model",
  modelAliases = {},
}) {
  const [searchQuery, setSearchQuery] = useState("");
  const [combos, setCombos] = useState([]);

  // Fetch combos when modal opens
  useEffect(() => {
    if (isOpen) {
      fetch("/api/combos")
        .then(res => res.json())
        .then(data => setCombos(data.combos || []))
        .catch(() => setCombos([]));
    }
  }, [isOpen]);

  const allProviders = { ...OAUTH_PROVIDERS, ...APIKEY_PROVIDERS };

  // Group models by provider with priority order
  const groupedModels = useMemo(() => {
    const groups = {};
    
    // Get active provider IDs
    const activeProviderIds = activeProviders.length > 0 
      ? activeProviders.map(p => p.provider)
      : PROVIDER_ORDER;

    // Sort by PROVIDER_ORDER
    const sortedProviderIds = [...activeProviderIds].sort((a, b) => {
      const indexA = PROVIDER_ORDER.indexOf(a);
      const indexB = PROVIDER_ORDER.indexOf(b);
      return (indexA === -1 ? 999 : indexA) - (indexB === -1 ? 999 : indexB);
    });

    sortedProviderIds.forEach((providerId) => {
      const alias = PROVIDER_ID_TO_ALIAS[providerId] || providerId;
      const providerInfo = allProviders[providerId] || { name: providerId, color: "#666" };
      
      // For passthrough providers, get models from aliases
      if (providerInfo.passthroughModels) {
        const aliasModels = Object.entries(modelAliases)
          .filter(([, fullModel]) => fullModel.startsWith(`${alias}/`))
          .map(([aliasName, fullModel]) => ({
            id: fullModel.replace(`${alias}/`, ""),
            name: aliasName,
            value: fullModel,
          }));
        
        if (aliasModels.length > 0) {
          groups[providerId] = {
            name: providerInfo.name,
            alias: alias,
            color: providerInfo.color,
            models: aliasModels,
          };
        }
      } else {
        const models = getModelsByProviderId(providerId);
        if (models.length > 0) {
          groups[providerId] = {
            name: providerInfo.name,
            alias: alias,
            color: providerInfo.color,
            models: models.map((m) => ({
              id: m.id,
              name: m.name,
              value: `${alias}/${m.id}`,
            })),
          };
        }
      }
    });

    return groups;
  }, [activeProviders, modelAliases, allProviders]);

  // Filter combos by search query
  const filteredCombos = useMemo(() => {
    if (!searchQuery.trim()) return combos;
    const query = searchQuery.toLowerCase();
    return combos.filter(c => c.name.toLowerCase().includes(query));
  }, [combos, searchQuery]);

  // Filter models by search query
  const filteredGroups = useMemo(() => {
    if (!searchQuery.trim()) return groupedModels;

    const query = searchQuery.toLowerCase();
    const filtered = {};

    Object.entries(groupedModels).forEach(([providerId, group]) => {
      const matchedModels = group.models.filter(
        (m) =>
          m.name.toLowerCase().includes(query) ||
          m.id.toLowerCase().includes(query) ||
          group.name.toLowerCase().includes(query)
      );

      if (matchedModels.length > 0) {
        filtered[providerId] = {
          ...group,
          models: matchedModels,
        };
      }
    });

    return filtered;
  }, [groupedModels, searchQuery]);

  const handleSelect = (model) => {
    onSelect(model);
    onClose();
    setSearchQuery("");
  };

  return (
    <Modal
      isOpen={isOpen}
      onClose={() => {
        onClose();
        setSearchQuery("");
      }}
      title={title}
      size="md"
      className="!p-4"
    >
      {/* Search - compact */}
      <div className="mb-3">
        <div className="relative">
          <span className="material-symbols-outlined absolute left-2.5 top-1/2 -translate-y-1/2 text-text-muted text-[16px]">
            search
          </span>
          <input
            type="text"
            placeholder="Search..."
            value={searchQuery}
            onChange={(e) => setSearchQuery(e.target.value)}
            className="w-full pl-8 pr-3 py-1.5 bg-surface border border-border rounded text-xs focus:outline-none focus:ring-1 focus:ring-primary/50"
          />
        </div>
      </div>

      {/* Models grouped by provider - compact */}
      <div className="max-h-[300px] overflow-y-auto space-y-3">
        {/* Combos section - always first */}
        {filteredCombos.length > 0 && (
          <div>
            <div className="flex items-center gap-1.5 mb-1.5 sticky top-0 bg-surface py-0.5">
              <span className="material-symbols-outlined text-primary text-[14px]">layers</span>
              <span className="text-xs font-medium text-primary">Combos</span>
              <span className="text-[10px] text-text-muted">({filteredCombos.length})</span>
            </div>
            <div className="flex flex-wrap gap-1.5">
              {filteredCombos.map((combo) => {
                const isSelected = selectedModel === combo.name;
                return (
                  <button
                    key={combo.id}
                    onClick={() => handleSelect({ id: combo.name, name: combo.name, value: combo.name })}
                    className={`
                      px-2 py-1 rounded-xl text-xs font-medium transition-all border hover:cursor-pointer
                      ${isSelected 
                        ? "bg-primary text-white border-primary" 
                        : "bg-surface border-border text-text-main hover:border-primary/50 hover:bg-primary/5"
                      }
                    `}
                  >
                    {combo.name}
                  </button>
                );
              })}
            </div>
          </div>
        )}

        {/* Provider models */}
        {Object.entries(filteredGroups).map(([providerId, group]) => (
          <div key={providerId}>
            {/* Provider header */}
            <div className="flex items-center gap-1.5 mb-1.5 sticky top-0 bg-surface py-0.5">
              <div
                className="w-2 h-2 rounded-full"
                style={{ backgroundColor: group.color }}
              />
              <span className="text-xs font-medium text-primary">
                {group.name}
              </span>
              <span className="text-[10px] text-text-muted">
                ({group.models.length})
              </span>
            </div>

            {/* Models as wrap chips - compact */}
            <div className="flex flex-wrap gap-1.5">
              {group.models.map((model) => {
                const isSelected = selectedModel === model.value;
                return (
                  <button
                    key={model.id}
                    onClick={() => handleSelect(model)}
                    className={`
                      px-2 py-1 rounded-xl text-xs font-medium transition-all border hover:cursor-pointer
                      ${isSelected 
                        ? "bg-primary text-white border-primary" 
                        : "bg-surface border-border text-text-main hover:border-primary/50 hover:bg-primary/5"
                      }
                    `}
                  >
                    {model.name}
                  </button>
                );
              })}
            </div>
          </div>
        ))}

        {Object.keys(filteredGroups).length === 0 && filteredCombos.length === 0 && (
          <div className="text-center py-4 text-text-muted">
            <span className="material-symbols-outlined text-2xl mb-1 block">
              search_off
            </span>
            <p className="text-xs">No models found</p>
          </div>
        )}
      </div>
    </Modal>
  );
}