package main

import (
	"encoding/csv"
	"fmt"
	"os"
	"strconv"
	"strings"
)

type StateData struct {
	State     string
	Votes     int
	Party2000 string
	Party2004 string
	Party2008 string
	Party2012 string
	Party2016 string
	Party2020 string
}

func readStateData() ([]StateData, error) {
	var statesData map[string]StateData = make(map[string]StateData)
	var years = []string{"2000", "2004", "2008", "2012", "2016", "2020"}

	/* Electoral votes for the 2004 election*/
	votesFilename := "data/electoral-college-votes.csv"
	votesFile, err := os.Open(votesFilename)
	if err != nil {
		return nil, fmt.Errorf("error opening the votes file: %v", err)
	}
	defer votesFile.Close()
	votesReader := csv.NewReader(votesFile)
	if _, err := votesReader.Read(); err != nil { // Skip header
		return nil, fmt.Errorf("error reading votes header: %v", err)
	}
	for {
		record, err := votesReader.Read()
		if err != nil {
			break // EOF or an error
		}
		votes, err := strconv.Atoi(record[1])
		if err != nil {
			continue // Error in converting votes, skip this record
		}
		state := record[0]
		if _, exists := statesData[state]; !exists {
			statesData[state] = StateData{State: state, Votes: votes}
		}
	}

	/* Election results */
	for _, year := range years {
		resultsFilename := fmt.Sprintf("data/results/%s.csv", year)
		resultsFile, err := os.Open(resultsFilename)
		if err != nil {
			return nil, fmt.Errorf("error opening the results file for %s: %v", year, err)
		}
		defer resultsFile.Close()
		resultsReader := csv.NewReader(resultsFile)
		if _, err := resultsReader.Read(); err != nil { // Skip header
			return nil, fmt.Errorf("error reading results header for %s: %v", year, err)
		}
		for {
			record, err := resultsReader.Read()
			if err != nil {
				break // EOF or an error
			}
			state, party := record[0], record[1]
			data, exists := statesData[state]
			if !exists {
				continue // State not found in votes map, skip
			}
			// Update the party winning in the specific year
			switch year {
			case "2000":
				data.Party2000 = party
			case "2004":
				data.Party2004 = party
			case "2008":
				data.Party2008 = party
			case "2012":
				data.Party2012 = party
			case "2016":
				data.Party2016 = party
			case "2020":
				data.Party2020 = party
			}
			statesData[state] = data
		}
	}

	// Convert statesData map to a slice for returning
	var dataSlice []StateData
	for _, data := range statesData {
		dataSlice = append(dataSlice, data)
	}

	return dataSlice, nil
}

func main() {
	stateDatas, err := readStateData()
	if err != nil {
		fmt.Println("Error:", err)
		return
	}

	// Example states to query
	states := []string{"California", "Texas", "Florida"}
	for _, stateData := range stateDatas {
		for _, state := range states {
			if strings.EqualFold(stateData.State, state) {
				fmt.Printf("%s: Votes: %d, Winners: 2000 - %s, 2004 - %s, 2008 - %s, 2012 - %s, 2016 - %s, 2020 - %s\n",
					stateData.State, stateData.Votes,
					stateData.Party2000, stateData.Party2004, stateData.Party2008,
					stateData.Party2012, stateData.Party2016, stateData.Party2020)
				break
			}
		}
	}
}