/*
Fonctions d'interaction avec la base de données
*/
#include <stdio.h>
#include <stdlib.h>
#include <sqlite3.h>
#include <unistd.h>
#include <assert.h>
#include <string.h>

#include "include/colors.h"
#include "include/config.h"
#include "include/struct.h"


char* get_db_path() {
    #ifndef DB_FILE
        //! We should check that $HOME/.config already exists even if it should be the case
        char* base_path = ".config/takl.sqlite3";

        char* home_dir = getenv("HOME");
        assert(home_dir != NULL);

        char* db_path = malloc(sizeof(char)*(strlen(base_path)+strlen(home_dir)+1));
        sprintf(db_path, "%s/%s", home_dir, base_path);

        return db_path;
    #else
        char* db_path = malloc(sizeof(char)*(strlen(DB_FILE)+1));
        memcpy(db_path, DB_FILE, sizeof(char)*(strlen(DB_FILE)+1));

        return db_path;
    #endif
}


sqlite3* get_db() {
    sqlite3* db;
    char* db_path = get_db_path();

    if (access(db_path, F_OK) != 0) {
        // Create DB
        sqlite3_open(db_path, &db);

        char* zErrMsg = NULL;
        int ret = sqlite3_exec(
            db,
            "CREATE TABLE tasks ( \
            id INTEGER PRIMARY KEY,\
            text TEXT NOT NULL,\
            done INTEGER, \
            due_to INTEGER \
            );",
            NULL,
            NULL,
            &zErrMsg
        );

        if (ret != SQLITE_OK) {
            fprintf(stderr, "(db creation) SQL error: %s\n", zErrMsg);
            sqlite3_free(zErrMsg);
        }

        sqlite3_close(db);

        printf(GREEN "OK" RESET " Base de données créée\n");
    }
    
    int ret = sqlite3_open(db_path, &db);
    if (ret != SQLITE_OK) {
        fprintf(stderr, "(get_db) Unable to open db\n");
    }

    free(db_path);
    return db;
}


int add_task(task_t t) {
    sqlite3* db = get_db();
    sqlite3_stmt* stmt;

    int ret = sqlite3_prepare_v2(db, "INSERT INTO tasks (id, text, done, due_to) VALUES (?1, ?2, ?3, ?4);", -1, &stmt, 0);

    if (ret != SQLITE_OK) {
        printf("(get_task) failure fetching data\n");
        return 1;
    }

    char str_id[10];
    sprintf(str_id, "%d", (int)t.id);
    sqlite3_bind_text(stmt, 1, str_id, -1, SQLITE_STATIC);
    sqlite3_bind_text(stmt, 2, t.text, -1, SQLITE_STATIC);

    char str_done[2]; // Just a boolean
    sprintf(str_done, "%d", t.done);
    sqlite3_bind_text(stmt, 3, str_done, -1, SQLITE_STATIC);

    char str_due_to[15];
    sprintf(str_due_to, "%ld", t.due_to);
    sqlite3_bind_text(stmt, 4, str_due_to, -1, SQLITE_STATIC);


    ret = sqlite3_step(stmt);

    sqlite3_finalize(stmt);
    sqlite3_close(db);

    if (ret != SQLITE_DONE) {
        if (ret == 19) {
            printf("Identifiant déjà utilisé\n");
        } else {
            printf("Return value: %d\n", ret);
        }

        return 1;
    }
    return 0;
}

int update_task(task_t t) {
    sqlite3* db = get_db();
    sqlite3_stmt* stmt;

    int ret = sqlite3_prepare_v2(db, "UPDATE tasks SET text=?2, done=?3, due_to=?4 WHERE id=?1;", -1, &stmt, 0);

    if (ret != SQLITE_OK) {
        printf("(get_task) failure fetching data\n");
        return 1;
    }

    char str_id[10];
    sprintf(str_id, "%d", (int)t.id);
    sqlite3_bind_text(stmt, 1, str_id, -1, SQLITE_STATIC);
    sqlite3_bind_text(stmt, 2, t.text, -1, SQLITE_STATIC);

    char str_done[2]; // Just a boolean
    sprintf(str_done, "%d", t.done);
    sqlite3_bind_text(stmt, 3, str_done, -1, SQLITE_STATIC);

    char str_due_to[15];
    sprintf(str_due_to, "%ld", t.due_to);
    sqlite3_bind_text(stmt, 4, str_due_to, -1, SQLITE_STATIC);


    ret = sqlite3_step(stmt);

    sqlite3_finalize(stmt);
    sqlite3_close(db);

    if (ret != SQLITE_DONE) {
        printf("Return value: %d\n", ret);
        return 1;
    }
    return 0;
}


void delete_task(int id) {
    sqlite3* db = get_db();
    sqlite3_stmt* stmt;

    int ret = sqlite3_prepare_v2(db, "DELETE FROM tasks WHERE id=?1;", -1, &stmt, 0);

    if (ret != SQLITE_OK) {
        printf("(get_task) failure fetching data\n");
        exit(1);
    }

    char str_id[10];
    sprintf(str_id, "%d", id);
    sqlite3_bind_text(stmt, 1, str_id, -1, SQLITE_STATIC);

    sqlite3_step(stmt);

    sqlite3_finalize(stmt);
    sqlite3_close(db);
}


void get_task(int id, task_t* t) {
    t->id = -1;

    sqlite3* db = get_db();
    sqlite3_stmt* stmt;

    int ret = sqlite3_prepare_v2(db, "SELECT id, text, done, due_to FROM tasks WHERE id=?1;", -1, &stmt, 0);

    if (ret != SQLITE_OK) {
        printf("(get_task) failure fetching data\n");
        exit(1);
    }
        

    char str_id[10];
    sprintf(str_id, "%d", id);
    sqlite3_bind_text(stmt, 1, str_id, -1, SQLITE_STATIC);

    ret = sqlite3_step(stmt);
    if (ret == SQLITE_ROW) {
        t->id = strtol((char*)sqlite3_column_text(stmt, 0), NULL, 10);
        t->done = strtol((char*)sqlite3_column_text(stmt, 2), NULL, 10);
        t->due_to = strtol((char*)sqlite3_column_text(stmt, 3), NULL, 10);

        char* text = (char*)sqlite3_column_text(stmt, 1);
        t->text = malloc(sizeof(char)*(strlen(text)+1));
        strcpy(t->text, text);
    }

    sqlite3_finalize(stmt);
    sqlite3_close(db);

    // t->id will be (-1) if not found
}

int list_tasks(bool show_completed) {
    sqlite3* db = get_db();
    sqlite3_stmt *stmt;

    int ret = sqlite3_prepare_v2(db, "SELECT id, text, done, due_to FROM tasks;", -1, &stmt, NULL);

    if (ret != SQLITE_OK) {
        printf("(get_task) failure fetching data\n");
        return 1;
    }

    time_t now = time(0);
    while (sqlite3_step(stmt) == SQLITE_ROW) {
        task_t t;

        t.id = strtol((char*)sqlite3_column_text(stmt, 0), NULL, 10);
        t.text = (char*)sqlite3_column_text(stmt, 1);
        t.done = strtol((char*)sqlite3_column_text(stmt, 2), NULL, 10);
        t.due_to = strtol((char*)sqlite3_column_text(stmt, 3), NULL, 10);
        //* Warning: t just lives here (particularly t.text)

        if (t.done) {
            if (show_completed) {
                printf(BOLD GREEN); // Task completed
            }
        } else if (difftime(now, t.due_to) <= 0 || t.due_to == 0) {
            printf(BOLD YELLOW); // Task not completed but that is fine
        } else {
            printf(BOLD RED); // Task not completed but should be !
        }

        if (!t.done || show_completed) {
            printf("[%d]" RESET " %s\n", t.id, t.text);
        }
    }

    sqlite3_finalize(stmt);
    sqlite3_close(db);

    return 0;
}

int get_new_task_id() {
    task_t t;

    int new_id = rand() %MAX_TASK_ID;
    t.id = new_id;

    int i=0;
    while (t.id != -1 && i < NEW_TASK_ID_MAX_RETRIES) { // If t.id==-1, task is not found so the id is sage to use
        new_id = rand() %MAX_TASK_ID;
        get_task(new_id, &t);
        i++;
    }

    if (i == NEW_TASK_ID_MAX_RETRIES) {
        printf(RED BOLD "Il semblerait que vous ayez un nombre de tâches se rapprochant de %d.\n" RESET, MAX_TASK_ID);
        printf(YELLOW "Il peut être judicieux de supprimer les tâches effectuées pour libérer de la place (et des identifiants).\n");
        printf("Vous pouvez également modifier la limite du nombre d'identifiants et recompiler le projet.\n" RESET);
        return -1;
    }

    return new_id;
}