import { defineStore } from "pinia";
import {
  MinFullNameSearchLength,
  bbClassRe,
  contextClassRe,
  dayMap,
  englishClassRe,
  firstPhaseClassRe,
  toTime,
} from "../helpers";
import {
  TaughtClass,
  ClassSelectorColumn,
  Ordering,
  FilterRule,
  ModuleLanguages,
  ClassesVersion,
  SemesterConfiguration,
} from "../types";
import { useClassVersionStore } from "./ClassVersion";
import { useModulesStore } from "./modules";
import { usePlanningStore } from "./planning";
import { useStateStore } from "./state";
import { useStudenthubStore } from "./studenthub";

// eslint-disable-next-line
type SortingFunction = (o1: any, o2: any) => number;

export const useClassesStore = defineStore("classes", {
  state: () => {
    const stateStore = useStateStore();
    const cvStore = useClassVersionStore();

    return {
      data: {} as Record<string, ClassesVersion>,
      filterRules: [
        {
          column: ClassSelectorColumn.Degree,
          filterData: { degree: `${stateStore.lastSelectedDegreeProgram}` },
          pk: Math.floor(Math.random() * 1e20),
          enabled: true,
        },
        {
          column: ClassSelectorColumn.Module,
          filterData: { term: "" },
          pk: Math.floor(Math.random() * 1e20),
          enabled: true,
        },
      ] as FilterRule[],
      sortBy: {} as Record<string, SortingFunction>,
      cvStore,
    };
  },

  getters: {
    allClasses(): TaughtClass[] {
      const cd = this.currentData;
      if (cd == null) return [];
      return [...cd.taughtClasses, ...cd.blockClasses];
    },
    classesFilteredByCompletion(): TaughtClass[] {
      const stateStore = useStateStore();
      if (!stateStore.hideCompletedClasses) return this.allClasses;

      const studenthubStore = useStudenthubStore();
      return this.allClasses.filter((c) => {
        const m = c.module;
        if (m?.module_id == null) return true;
        return !studenthubStore.hasCompletedModule(m.module_id);
      });
    },
    getAllSortedClasses(): TaughtClass[] {
      const keys = Object.keys(this.sortBy);
      const numberOfProperties = keys.length;
      let modules = [...this.classesFilteredByCompletion];

      if (numberOfProperties > 0) {
        modules = modules.sort((obj1, obj2) => {
          let i = 0;
          let result = 0;

          while (result === 0 && i < numberOfProperties) {
            result = this.sortBy[keys[i]](obj1, obj2);
            i++;
          }

          return result;
        });
      }
      return modules;
    },
    filteredModules(): TaughtClass[] {
      let classes = this.getAllSortedClasses;

      const transformedRules = {} as Record<ClassSelectorColumn, FilterRule[]>;
      this.filterRules.forEach((rule) => {
        if (!rule.enabled) return;
        if (rule.column in transformedRules)
          transformedRules[rule.column].push(rule);
        else transformedRules[rule.column] = [rule];
      });

      Object.keys(transformedRules).forEach((column) => {
        const foundClasses = [] as TaughtClass[];
        let didFilter = false;

        if (column == ClassSelectorColumn.Time) {
          transformedRules[column].forEach((rule) =>
            foundClasses.push(...filterTimeColumn(classes, rule)),
          );
          classes = [...new Set(foundClasses)];
          return;
        }

        if (column == ClassSelectorColumn.Degree) {
          let shouldFilter = true;
          transformedRules[column].forEach((rule) => {
            const degree = rule.filterData?.degree ?? "";
            if (degree.length == 0) {
              shouldFilter = false;
              return;
            }
            didFilter = true;
            foundClasses.push(
              ...classes.filter((c) => c.degree_prg == rule.filterData.degree),
            );
          });

          if (shouldFilter && didFilter) classes = [...new Set(foundClasses)];
          return;
        }

        switch (column) {
          case ClassSelectorColumn.Module:
            transformedRules[column].forEach((rule) => {
              const term = rule.filterData?.term?.toLowerCase() ?? "";
              const checkName = term.length >= MinFullNameSearchLength;
              if (term.length == 0) return;
              didFilter = true;
              foundClasses.push(
                ...classes.filter(
                  (c) =>
                    c.name.toLowerCase().includes(term) ||
                    (checkName &&
                      c.module?.name.toLocaleLowerCase().includes(term)),
                ),
              );
            });
            break;

          case ClassSelectorColumn.Room:
            transformedRules[column].forEach((rule) => {
              const term = rule.filterData?.term?.toLowerCase() ?? "";
              if (term.length == 0) return;
              didFilter = true;
              const clsss = classes.filter((c) => {
                if (c.rooms.length == 0) return false;
                return c.rooms.join(" ").toLowerCase().includes(term);
              });
              foundClasses.push(...clsss);
            });
            break;

          case ClassSelectorColumn.Class:
            transformedRules[column].forEach((rule) => {
              const term = rule.filterData?.term?.toLowerCase() ?? "";
              if (term.length == 0) return;
              didFilter = true;
              foundClasses.push(
                ...classes.filter((c) => c.class.toLowerCase().includes(term)),
              );
            });
            break;

          case ClassSelectorColumn.Lecturer:
            transformedRules[column].forEach((rule) => {
              const term = rule.filterData?.term?.toLowerCase() ?? "";
              if (term.length == 0) return;
              didFilter = true;
              foundClasses.push(
                ...classes.filter((c) =>
                  c.teachers.join().toLowerCase().includes(term),
                ),
              );
            });
            break;

          case ClassSelectorColumn.TeachingType:
            transformedRules[column].forEach((rule) => {
              if (rule.filterData.teachingType?.length == 0) return;

              didFilter = true;
              foundClasses.push(
                ...classes.filter(
                  (c) => c.teaching_type == rule.filterData.teachingType,
                ),
              );
            });
            break;

          default:
            console.warn(`Filter type ${column} is not supported!`);
            return;
        }
        if (didFilter) classes = [...new Set(foundClasses)];
      });

      return classes;
    },
    degreePrograms(): string[] {
      const cd = this.currentData;
      if (cd == null) return [];
      return cd.degreePrograms;
    },
    currentData(): ClassesVersion | null {
      const version = this.cvStore.semVer;
      if (version == null) return null;
      if (!(version in this.data)) {
        console.error(`The version ${version} has not yet been loaded!`);
        return null;
      }

      return this.data[version];
    },
  },

  actions: {
    fetchData(version: string | null = null): Promise<null> {
      if (version == null) {
        version = this.cvStore.semVer;

        if (version == null) {
          // console.error("The current semester/version was unexpectedly null!");
          return new Promise((res, rej) => rej);
        }
      }

      // Check if the data has already been loaded
      if (version in this.data)
        return this.data[version].ready ?? new Promise((res, rej) => rej);

      const semVer = version;
      this.data[semVer] = {
        version: semVer,
        ready: null,
        loaded: false,
        teachers: [],
        rooms: [],
        classes: [],
        days: [],
        taughtClasses: [],
        blockClasses: [],
        degreePrograms: [],
        config: { blockclass_file: "block.pdf" },
      };

      const semVerFolder = this.cvStore.semVerFolderFromSemVer(semVer);
      const semesterFolder = this.cvStore.semesterFolderFromSemVer(semVer);

      this.data[semVer].ready = new Promise((resolve, reject) => {
        const fe = fetch(`${semVerFolder}/classes.json`);
        const bc = fetch(`${semesterFolder}/blockclasses.json`);
        const sc = fetch(`${semesterFolder}/config.json`);
        const modulesStore = useModulesStore();

        const addModuleGetters = (cls: TaughtClass) => {
          Object.defineProperty(cls, "module", {
            get: function () {
              return (
                this._module ||
                (this._module = modulesStore.fromModuleShort(cls.name))
              );
            },
          });
          cls.isBB = cls.class.match(bbClassRe) !== null;
          cls.isFirstPhase = cls.class.match(firstPhaseClassRe) !== null;
          cls.isEnglish = cls.class.match(englishClassRe) !== null;
          cls.isContext = cls.class.match(contextClassRe) !== null;
          cls.languageString = cls.isEnglish
            ? ModuleLanguages.EN
            : ModuleLanguages.DE;
          cls.executionTime =
            cls.weekday !== null
              ? `${dayMap[cls.weekday]}, ${toTime(cls.from)}-${toTime(cls.to)}`
              : "Blockmodul";
        };

        /**
         * Process the block modules
         */
        const bmReady = new Promise((resolveBM) => {
          Promise.all([bc, modulesStore.ready])
            .then((response) => response[0].json())
            .then((data: TaughtClass[]) => {
              data.forEach(addModuleGetters);
              this.data[semVer].blockClasses = data;
              resolveBM(null);
            })
            .catch((error) => {
              console.error(error);
              this.data[semVer].blockClasses = [];
              resolveBM(null); // We will resolve and not reject, as it's okay to not have a blockmodules.json on the server
            });
        });

        /**
         * Process the semester config
         */
        const scReady = new Promise((resolveSC) => {
          Promise.all([sc, modulesStore.ready])
            .then((response) => response[0].json())
            .then((data: SemesterConfiguration) => {
              this.data[semVer].config = data;
              resolveSC(null);
            })
            .catch((error) => {
              console.error(error);
              this.data[semVer].config = { blockclass_file: "block.pdf" };
              resolveSC(null); // We will resolve and not reject, as it's okay to not have a blockmodules.json on the server
            });
        });

        /**
         * Process the standard classes
         */
        Promise.all([fe, bmReady, scReady, modulesStore.ready])
          .then((response) => (response[0] as Response).json())
          .then((data: TaughtClass[]) => {
            data.forEach(addModuleGetters);
            this.data[semVer].taughtClasses = data;
            this.updateUniqueDegreePrograms(semVer);

            this.data[semVer].loaded = true;

            const planningStore = usePlanningStore();
            planningStore.loadFromStorage();
            resolve(null);
          })
          .catch((error) => {
            console.error(error);
            this.data[semVer].taughtClasses = [];
            reject(null);
          });
      });

      return this.data[version].ready ?? new Promise((res, rej) => rej);
    },
    updateUniqueDegreePrograms(version: string) {
      this.data[version].degreePrograms = [];

      this.allClasses.forEach((m) => {
        if (
          m.degree_prg.length > 0 &&
          !this.data[version].degreePrograms.includes(m.degree_prg)
        )
          this.data[version].degreePrograms.push(m.degree_prg);
      });

      this.data[version].degreePrograms.sort((a, b) =>
        a.toLowerCase().localeCompare(b.toLowerCase()),
      );
    },
    getById(module_id: string): TaughtClass | null {
      const matched = this.allClasses.filter((c) => c.id == module_id);

      if (matched.length == 0) return null;
      return matched[0];
    },
    updateOrdering(col: ClassSelectorColumn, dir: Ordering) {
      const colName = col.valueOf();

      if (dir == Ordering.None && col in this.sortBy) {
        delete this.sortBy[col];
        return;
      }

      switch (col) {
        case ClassSelectorColumn.Time:
          this.sortBy[col] = (a: TaughtClass, b: TaughtClass) => {
            const ta = 86400 * (a.weekday ?? 0) + a.from;
            const tb = 86400 * (b.weekday ?? 0) + b.from;
            return (ta - tb) * dir;
          };
          break;

        case ClassSelectorColumn.Lecturer:
          this.sortBy[col] = (a: TaughtClass, b: TaughtClass) => {
            const ta = a.teachers.join("").toLowerCase();
            const tb = b.teachers.join("").toLowerCase();
            return (ta < tb ? -1 : ta > tb ? 1 : 0) * dir;
          };
          break;

        case ClassSelectorColumn.TeachingType:
          this.sortBy[col] = (a: TaughtClass, b: TaughtClass) => {
            const ta = a.teaching_type;
            const tb = b.teaching_type;
            return (ta < tb ? -1 : ta > tb ? 1 : 0) * dir;
          };
          break;

        case ClassSelectorColumn.Room:
          this.sortBy[col] = (a: TaughtClass, b: TaughtClass) => {
            const ta = a.rooms.join("").toLowerCase();
            const tb = b.rooms.join("").toLowerCase();
            return (ta < tb ? -1 : ta > tb ? 1 : 0) * dir;
          };
          break;

        case ClassSelectorColumn.MSP:
          this.sortBy[col] = (a: TaughtClass, b: TaughtClass) => {
            const aMSP = a.module?.hasMSP === true;
            const bMSP = b.module?.hasMSP === true;
            return (aMSP == bMSP ? 0 : aMSP ? -1 : 1) * dir;
          };
          break;

        case ClassSelectorColumn.Module:
        case ClassSelectorColumn.Class:
          this.sortBy[col] = (a, b) =>
            (a[colName] < b[colName] ? -1 : a[colName] > b[colName] ? 1 : 0) *
            dir;
          break;

        default:
          console.error("Unhandled sorting!");
          break;
      }
    },
    insertFilter(afterFilter: FilterRule | null) {
      const emptyFilter = {
        column: ClassSelectorColumn.Module,
        filterData: { term: "" },
        pk: Math.floor(Math.random() * 1e20),
        enabled: true,
      } as FilterRule;

      if (!afterFilter) {
        this.filterRules.push(emptyFilter);
        return;
      }

      const idx = this.filterRules.findIndex((r) => r.pk == afterFilter.pk);
      if (idx == -1) {
        this.filterRules.push(emptyFilter);
        return;
      }

      this.filterRules.splice(idx + 1, 0, emptyFilter);
    },
    removeFilter(filterRule: FilterRule) {
      const idx = this.filterRules.findIndex((r) => r.pk == filterRule.pk);
      if (idx == -1) {
        console.error("Failed to find the filter rule in the current set!");
        return;
      }
      this.filterRules.splice(idx, 1);
    },
    classesForModule(short: string): TaughtClass[] {
      const cd = this.currentData;
      if (cd == null) return [];

      return cd.taughtClasses.filter((c) => c.name == short);
    },
  },
});

function filterTimeColumn(
  modules: TaughtClass[],
  filterset: FilterRule,
): TaughtClass[] {
  const timeData = filterset.filterData as Record<string, number>;
  const start = timeData.startTime;
  const end = timeData.endTime;
  if (start == undefined && end == undefined) return modules;
  let startingDay = -1;

  if (start != undefined) {
    if (start < 0) {
      const pStart = -1 * start;
      modules = modules.filter((m) => m.from >= pStart);
    } else {
      startingDay = Math.floor(start / 86400);
      const startingTime = start - startingDay * 86400;
      modules = modules.filter(
        (m) =>
          ((m.weekday ?? 0) == startingDay && m.from >= startingTime) ||
          (m.weekday ?? 0) > startingDay,
      );
    }
  }

  if (end != undefined) {
    let aEnd = end;
    if (aEnd < 0) {
      if (startingDay >= 0) {
        const endingTime = aEnd * -1 - startingDay * 86400;
        modules = modules.filter(
          (m) =>
            (m.weekday ?? 0) == startingDay &&
            (endingTime == 0 || m.to <= endingTime),
        );
      } else {
        aEnd *= -1;
        modules = modules.filter((m) => m.to <= aEnd);
      }
    } else {
      const endingDay = Math.floor(aEnd / 86400);
      const endingTime = aEnd - endingDay * 86400;
      modules = modules.filter(
        (m) =>
          (m.weekday ?? 0) < endingDay ||
          ((m.weekday ?? 0) == endingDay &&
            (endingTime == 0 || m.to <= endingTime)),
      );
    }
  }
  return modules;
}